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Mark rsa2au
07-27-2013, 10:53 PM
Hi Guys, can any one tell me if there is an electronic rev limiter on the 310HP Preditor Motor/ 2001 350 TBI motor? If there is can I remove it? If not I still have a problem....

Once it gets to about 4500rpm, it seems to hit a wall and start to pull revs out to about 4300 then back up the 4500 etc. It is almost like a soft cut out rev limiter in a car, but lazy. Throttle is at about 2/3 and not full. Speed is about 38-39 mph.

Once run at high speed (Barefooting) and it hits this rpm, we shut down to get person in boat. Then I find the motor will start, kick over and die. It will do this untill I open the throttle and start on fast idle, then it starts ok and runs and starts fine.

Any ideas appreciated!!

Note the following parts have been replaced / repaired over the last 4 months:
Fuel filters, injectors, pump & pipes (pressure 25psi across the range). Also new sparkplugs, leads, distributer(cap and rotor), battery and cables. Also MAP and TPS, AIC. Also replaced all temp sensors, thermostats, impeller and pump.

Thanks a ton!

Mark rsa2au
07-30-2013, 06:26 PM
I am going to be installing an automotive ignition module that is commonly used to see if it the electronics pulling revs out. Pick it up tomorrow.

Also any clues on the max rpm of the motors? I thought it would be arround 4800 - 5000rpm.

Just a thought, if I tested it on the trailer and it revs up to 5000 then it would not be an electronic rev limiter but another fault? Might test it tonight.

maxpower220
07-31-2013, 08:31 AM
I believe the Indmar manual states a need for 30 psi. I don't know if that 5 psi difference would effect the boat like that or not. Sorry, my only thought.

JimN
07-31-2013, 09:35 AM
Hi Guys, can any one tell me if there is an electronic rev limiter on the 310HP Preditor Motor/ 2001 350 TBI motor? If there is can I remove it? If not I still have a problem....

Once it gets to about 4500rpm, it seems to hit a wall and start to pull revs out to about 4300 then back up the 4500 etc. It is almost like a soft cut out rev limiter in a car, but lazy. Throttle is at about 2/3 and not full. Speed is about 38-39 mph.

Once run at high speed (Barefooting) and it hits this rpm, we shut down to get person in boat. Then I find the motor will start, kick over and die. It will do this untill I open the throttle and start on fast idle, then it starts ok and runs and starts fine.

Any ideas appreciated!!

Note the following parts have been replaced / repaired over the last 4 months:
Fuel filters, injectors, pump & pipes (pressure 25psi across the range). Also new sparkplugs, leads, distributer(cap and rotor), battery and cables. Also MAP and TPS, AIC. Also replaced all temp sensors, thermostats, impeller and pump.

Thanks a ton!

Check the fuel pickup in the tank and the anti-siphon attached to the aluminum block on the top of that. If it doesn't have an anti-siphon, make sure the fuel shut-off is fully open.

Stop replacing parts unless you can prove they're bad. I seriously doubt the MAP, TPS or IAC were faulty and the whole reason these engines have trouble codes is so time, effort and money isn't wasted on replacing parts.

The rev limiter kicks in at about 5200 RPM. The IC module isn't at fault- you already measured low fuel pressure and you need to keep going in that direction, IMO.

Mark rsa2au
07-31-2013, 07:37 PM
Check the fuel pickup in the tank and the anti-siphon attached to the aluminum block on the top of that. If it doesn't have an anti-siphon, make sure the fuel shut-off is fully open.

Stop replacing parts unless you can prove they're bad. I seriously doubt the MAP, TPS or IAC were faulty and the whole reason these engines have trouble codes is so time, effort and money isn't wasted on replacing parts.

The rev limiter kicks in at about 5200 RPM. The IC module isn't at fault- you already measured low fuel pressure and you need to keep going in that direction, IMO.

Thanks Jim

Great info! RPM limit 5200, boat does not get even close to this, 4500 max rpm from 3/4 throttle to WOT.

I will check the anti-syphon / fuel shut off is all good. Fuel pump module was removed, cleaned and new filter installed. Loads of muck in fuel pump inlet screen, fuel system now clean and performance has improved.
I also read in the manual that the fuel pressure is meant to be 25psi, although I have measured this at ignition, idle, and up to 2000 rpm and it holds 25 psi.
Because of the inherrant risk of holding a fuel pressure guage on the motor at full throttle on open water I have not done so but will be installing a fixed guage (and then removing it) for a test. The PO I believe turned the screw on the bottom of the pressure regulator out by 3 turns (because of a previous over fueling issue) so I might screw this back in as well.

The list of parts was either checked / repaired or replaced. ( not all replaced) This was meant to give a little history so those more experienced than me can see what has been done so far and provide me with addidtional valuable info... Which is excatly what you have done. Thanks!!!

JimN
07-31-2013, 07:41 PM
Thanks Jim

Great info! RPM limit 5200, boat does not get even close to this, 4500 max rpm from 3/4 throttle to WOT.

I will check the anti-syphon / fuel shut off is all good. Fuel pump module was removed, cleaned and new filter installed. Loads of muck in fuel pump inlet screen, fuel system now clean and performance has improved.
I also read in the manual that the fuel pressure is meant to be 25psi, although I have measured this at ignition, idle, and up to 2000 rpm and it holds 25 psi.
Because of the inherrant risk of holding a fuel pressure guage on the motor at full throttle on open water I have not done so but will be installing a fixed guage (and then removing it) for a test. The PO I believe turned the screw on the bottom of the pressure regulator out by 3 turns (because of a previous over fueling issue) so I might screw this back in as well.

The list of parts was either checked / repaired or replaced. ( not all replaced) This was meant to give a little history so those more experienced than me can see what has been done so far and provide me with addidtional valuable info... Which is excatly what you have done. Thanks!!!

What manual? We were told the pressure should be 30 pounds. The regulator isn't user-adjustable. It's possible to adjust it, but it's NOT supposed to be without doing it without the proper procedures.

Mark rsa2au
07-31-2013, 09:34 PM
What manual? We were told the pressure should be 30 pounds. The regulator isn't user-adjustable. It's possible to adjust it, but it's NOT supposed to be without doing it without the proper procedures.

AAHh yes...... the on line manual that says 30psi:( oops you are right, my bad!
Yes the fuel pressure regulator is adjustable via a screw below the bowl, (although should not be required) and he did unscrew it 3 turns. :confused:

I dont know how this will affect the fuel pressure at full throttle, as my limited understanding suggests fuel flow / volume will be the issue. If there is insufficient fuel flow then the pressure may be acceptable at low - medium revs but when full throttle is called for, the lack of flow will starve the engine for fuel and result in a low pressure reading. This is why I am installing a fuel pressure guage.

Regardless I will install guage and measure... Will let you know

Mark rsa2au
08-04-2013, 03:56 AM
Ok so I pulled on the arctic gear, pulled the boat out the garage and started playing. First thing to note is how much water is needed... I sucked my 2000lt rain water tank dry (528 gallons):eek:

Timing: The last time I checked the timing it was set at about 10 degrees at 1000rpm (using paperclip), but as it was hunting arround I set it about in the middle. NOW after much work the mark was a lot more stable and seemed to be about 2 degrees out. Set is exactly on 10 degrees, checked, turned off and resterted and checked again... stable at 10degrees:D

Fuel pressure: At key up and idle it was about 25 to 26psi. Adjusted Fuel pressure regulator to 30psi at idle/1000/2000/3000 rpm.

Also changed oil and oil filter while I was there.

Does anyone think the 2 degrees timing and the 4psi fuel difference would solve the issue of the lack of revs??

JimN
08-04-2013, 07:42 AM
Ok so I pulled on the arctic gear, pulled the boat out the garage and started playing. First thing to note is how much water is needed... I sucked my 2000lt rain water tank dry (528 gallons):eek:

Timing: The last time I checked the timing it was set at about 10 degrees at 1000rpm (using paperclip), but as it was hunting arround I set it about in the middle. NOW after much work the mark was a lot more stable and seemed to be about 2 degrees out. Set is exactly on 10 degrees, checked, turned off and resterted and checked again... stable at 10degrees:D

Fuel pressure: At key up and idle it was about 25 to 26psi. Adjusted Fuel pressure regulator to 30psi at idle/1000/2000/3000 rpm.

Also changed oil and oil filter while I was there.

Does anyone think the 2 degrees timing and the 4psi fuel difference would solve the issue of the lack of revs??

Which way was the timing off- low, or high? If it was low, it can affect idle, but it shouldn't be a major factor. At WOT, it wouldn't have much affect because base timing + maximum advance at speed would be near 40BTDC vs 38 and shouldn't cost you 400RPM.

Did you put the ECM in diagnostic mode? If you saw the timing mark jumping around, your base timing ISN'T at 10. The mark jumping means sparl stabilization is still operating and in diagnostic mode, it isn't. This is mandatory for setting base timing. You can put it in foagnostic mode by inserting a paper clip into terminals A and B of the DLC and setting the idle at 1000 RPM. The timing mark should be rock steady. Set it at 10BTDC, snug the bolt, check it again and tighten it before removing the paper clip.

As far as 4psi, if the pressure isn't high enough, the fuel won't atomize properly and this is important because it needs to do this in order to burn completely. If it doesn't burn completely, you can't develop full power. Also, if you didn't check the pressure at WOT, it may be close, but not exact. However, it will be closer than before and noticeable.

Mark rsa2au
09-01-2013, 07:22 AM
I am now over this POS!

Today ran the boat on the lake, Fathers day over here and a very nice spring day to get out on the water.

Last few weeks checked everything I can think of. Fuel pressure ( on trailer 30psi and on lake full throttle approx 30 PSI across the range). Timing at 10 degrees as per manual. All sensors checked or replaced. Plugs, leads, distributer and rotor replaced. Battery cables and connections replaced, earth connections cleaned and checked.
Boat starts first time every time. Dash guage shows temp slowly warming up to 160 and stays there give or take slight movement. Then the engine check light comes on so I disconnect the switch ( note this is just the on off switch- set to 180F- to the check engine light not the temp sensor).

Boat is now running rich again... on occasion have black smoke (replaced everything related so far except ECU), and will still not run above 4500rpm with out spluttering and poping or misfiring. Below this it pulls like a freight train.

Then the water intake hose splits at shower connection, and we almost sink...water over the floor boards. Lucky we now always cary tools on the Disastercraft, so wrap plastic and race tape (strong Duct tape) arround the pipe and carry on. No apparant dammage to motor dispite not having water. ( did not care anyway I'm so over this thing) Impellar checked and all good.

Guages still work on and off when they feel like it. Oil pressure guage now no longer works after today. Speedo's still slow to react and still leak from below dash (have replaced with new tubes as well).

Used a full tank (32 gallons) in just short of 3 hours measured on Tacho. Mainly water skiing, some wake boarding and a couple of tube rides. Boat cannot get to barefooting speed so we cannot foot behind it.

Finally the check engine light came on at the end of the day and stayed on, we were worried it would not restart so we left the engine running untill we put it on the trailer. Now parked on the verge as I could not be bothered to park it in the garage. No I have not checked the code yet..

The Disastercraft is THE most unreliable boat I have ever owned ( 5th boat). I have never had to work so hard to get a boat to run properly especialy one with just 270 hours on it.

Of course the Malibu in the team keeps purring along perfectly as it has done for the last 5 seasons, and the Australian made Sleekline (also 350 chev motor) still runs like a Swis Watch after 20 years. We can no longer ski our favorite spots because the family are scared the Disastercraft will break down and not get us back.

Does anyone have any ideas on what to check/replace next? Or we will have to trade it before summer.

JimN
09-01-2013, 10:07 AM
I am now over this POS!

Today ran the boat on the lake, Fathers day over here and a very nice spring day to get out on the water.

Last few weeks checked everything I can think of. Fuel pressure ( on trailer 30psi and on lake full throttle approx 30 PSI across the range). Timing at 10 degrees as per manual. All sensors checked or replaced. Plugs, leads, distributer and rotor replaced. Battery cables and connections replaced, earth connections cleaned and checked.
Boat starts first time every time. Dash guage shows temp slowly warming up to 160 and stays there give or take slight movement. Then the engine check light comes on so I disconnect the switch ( note this is just the on off switch- set to 180F- to the check engine light not the temp sensor).

Boat is now running rich again... on occasion have black smoke (replaced everything related so far except ECU), and will still not run above 4500rpm with out spluttering and poping or misfiring. Below this it pulls like a freight train.

Then the water intake hose splits at shower connection, and we almost sink...water over the floor boards. Lucky we now always cary tools on the Disastercraft, so wrap plastic and race tape (strong Duct tape) arround the pipe and carry on. No apparant dammage to motor dispite not having water. ( did not care anyway I'm so over this thing) Impellar checked and all good.

Guages still work on and off when they feel like it. Oil pressure guage now no longer works after today. Speedo's still slow to react and still leak from below dash (have replaced with new tubes as well).

Used a full tank (32 gallons) in just short of 3 hours measured on Tacho. Mainly water skiing, some wake boarding and a couple of tube rides. Boat cannot get to barefooting speed so we cannot foot behind it.

Finally the check engine light came on at the end of the day and stayed on, we were worried it would not restart so we left the engine running untill we put it on the trailer. Now parked on the verge as I could not be bothered to park it in the garage. No I have not checked the code yet..

The Disastercraft is THE most unreliable boat I have ever owned ( 5th boat). I have never had to work so hard to get a boat to run properly especialy one with just 270 hours on it.

Of course the Malibu in the team keeps purring along perfectly as it has done for the last 5 seasons, and the Australian made Sleekline (also 350 chev motor) still runs like a Swis Watch after 20 years. We can no longer ski our favorite spots because the family are scared the Disastercraft will break down and not get us back.

Does anyone have any ideas on what to check/replace next? Or we will have to trade it before summer.

If you aren't the original owner, it's very possible that something happened before, that's causing your problems. MC used the same engines as Malibu/PCM/Mercruiser/Volvo-Penta and any other brand with a Chevy and Indmar supplied then to MC and Malibu, so it's not an inherent problem with that. The speedo(s) leaking is usually caused by not purging the water out of the tubes at the end of the season and if the temperature drops below freezing, the water damages the diaphragm in the control box for the gauges. Once the water gets in, the electronics fail- this gauge package is common and these problems occur with all of the brands using it, but we don't see the incidents because most of us aren't exposed to them. A hose splitting is odd, but if the oil cooler (IIRC, it's after the raw water pump on your boat) is clogged, it could cause this.

The temperature sender for the gauge has nothing to do with what the ECM sees, or the check engine light. The coolant temperature sender with yellow/black wires is the one you need to check and I suspect this sender is behind the black smoke/rich/check engine light.

I don't remember if we discussed checking for codes, but that's the first thing needed now.

Rossterman
09-01-2013, 12:12 PM
Check engine to find the code using the paperclip method. As to what can illuminate the CEL, there are several items. One (i recently dealt with) was caused by a faulty high temp sensor. As was stated, this is different than the temp sender the ecu reads to determine if engine is hot or cold. If that sensor is reading cold when engine is warmed up, it will run too rich but i believe this feeds the dash guage too so probably is OK. . Knock sensor could be retarding timing if bad as well. You can buy one of those adhesive timing tapes from a speed shop that you put on the harmonic damper and check with a timing light if advance is working for ~ $10 if you want to 100% rule this out.

Sorry to hear you are having so many problems. Usually these boats are pretty trouble free ( provided they recieve the proper maintenance) but sometimes a boat just turns out to be a turd no matter how well maintained. No different than buying a car and getting a lemon.

One point in you note still puzzles me- why the PO was adjusting the fuel pressure regulator? These boats are FI so could be that the injectors are leaking by which can cause a rich idle if the temp sensor turns out to be OK. You may want to look in the throttle bore while at idle and at speed to see if they are both working correctly as well. These were used on tons of early chevys so you can look for ideas on the web there to get ideas. I remember one post where the injector was cutting out at high rpm due to loose wiring connection.

Good luck with your investigation and let us know what you find
Ross

Mark rsa2au
09-01-2013, 07:23 PM
Thanks JimN and Rossterman, sorry about the rant but I am so frustrated at the amount of time and money I am throwing at this boat. I do appreciate your replys!!

While the motor is a generic block, it is the Mastercraft specification / indmar electronics that seem to be causing the issues. I know these motors should be reliable which is why I bought one.

The Temp sender unit was replaced with a generic unit that was close to origional but not exact, so I replaced with an Indmar version. Boat does same with either Temp sender unit.

Melbourne does not get below freezing so I am not sure if the diaphram at fault. Started boat this morning on the verge and Oil guage is working again......? Might have to order a new MDC and guage pack.

Hose split at shower connection, plastic connection failed. Trans oil cooler checked and cleaned before it was put into the water.

We had an over fueling issue and the PO decided to take 3 turnes out of the fuel pressure regulater to try to reduce the overfueling. Now back to Standard

Checked code this morning = 44: (seen this one before and replaced MAF sensor)
Did not know if this motor has an O2 sensor.. Maf Sensor is new. Fuel Injectors are new, Fuel Pressure is 30psi across the range (approx at 4500rpm as it was hard to hold on at WOT and the motor popping and stuttering). Have run several tanks of fresh fuel, drained and cleaned fuel tank and replaced fuel filters, and cleaned fuel pump wire mesh. Cant understand Lean condition with black smoke out the back that smells like fuel.
Maybe the fuel pump is failing and is intermittant causing lean conditions then over fueling?
CODE 44
Trouble Code 44 indicates that the O2 sensor is showing a persistently high exhaust oxygen content (lean), despite the efforts of the ECM to increase injector on-time (thus increasing fuel delivered). Integrator and BLM numbers may indicate > 128 by a substantial margin.
The conditions for setting this code are:
no Code 33 or Code 34 (MAF Error) present, and
the O2 sensor voltage remains below 250 mVolts, and
the ECM is in Closed Loop control, and
the above conditions exist for more than 50 seconds.
Typical causes for this code include:
1) O2 sensor defective or lead shorted
2) Lean injectors (dirty or blocked)
3) Water in fuel
4) Exhaust leaks upstream of O2 sensor
5) Fuel pressure or volume too low
6) MAF sensor reading lower airflow than is actually present

Appreciate any ideas? Just not the one that suggests I take it into the MC Stealership....

Rossterman
09-02-2013, 02:46 AM
You sure you have a tbi predator? These don't have a maf sensor, rather use a map sensor for measuring manifold pressure. If tbi you will have a small round flame arrestor sitting where a carb would normally sit. If it has a big aluminum plenum and a throttle body pointing down at the front (or back depending if dd or vd), then it's a 330hp ltr with injector for each cylinder. Take a pic and we can confirm.

There is no 02 sensor so wierd that the code is saying that.

Just Checked online and code 44 is for a bad knock sensor not o2 sensor. If bad, it will reduce the timing and power...

Here's a post including info on the fact it can be bought at a auto parts store since isn't a marine specific part:

http://www.mastercraft.com/teamtalk/showthread.php?t=41782

Mark rsa2au
09-02-2013, 04:18 AM
Hey Rossterman, Thanks.

Is is a 310hp TBI Preditor motor with the 2 injectors on the top of the throttle body. Yep sorry MAP sensor that attaches to the throttle body. It was replaced like for like.

I will investigate the knock sensor!

Rossterman
09-02-2013, 04:28 AM
Here's the indmar MEFI book showing codes, how to check all sensors, etc

[PDF]Indmar Diagnostic Manual - Bakes Online
www.bakesonline.com/images/MediaLibrary/Indmar_MEFI4manual.pdf

Rossterman
09-02-2013, 04:34 AM
Saw one of your earlier post and how much crap was in the pump and filter. If stuff got past the filter and into the pump, it's through the whole system. You could have junk in the injectors causing them to leak by at idle and be flow restricted at speed. They are very intolerant of any debris.

Mark rsa2au
09-02-2013, 05:21 AM
Saw one of your earlier post and how much crap was in the pump and filter. If stuff got past the filter and into the pump, it's through the whole system. You could have junk in the injectors causing them to leak by at idle and be flow restricted at speed. They are very intolerant of any debris.

That fuel filter was shot!!! I have flushed the fuel lines and replaced the injectors with new ones. No harm pulling it out and cleaning again. The injectors dont leak/drip at idle or when shut down, and the spray pattern looks nice and even to the naked eye...?

and thanks for the diagnostic manual, some bedtime reading...

petermegan
09-02-2013, 05:47 AM
Man o man, you are having some problems. No help from me, but I did say just bring the slab not the boat for my Lake opening :) I am sure you will get this sorted. I have a spare brain box for your gauges if you want a loan?? Just let me know and can pop in the mail. Have Fun...

JimN
09-02-2013, 08:54 AM
Check engine to find the code using the paperclip method. As to what can illuminate the CEL, there are several items. One (i recently dealt with) was caused by a faulty high temp sensor. As was stated, this is different than the temp sender the ecu reads to determine if engine is hot or cold. If that sensor is reading cold when engine is warmed up, it will run too rich but i believe this feeds the dash guage too so probably is OK. . Knock sensor could be retarding timing if bad as well. You can buy one of those adhesive timing tapes from a speed shop that you put on the harmonic damper and check with a timing light if advance is working for ~ $10 if you want to 100% rule this out.

Sorry to hear you are having so many problems. Usually these boats are pretty trouble free ( provided they recieve the proper maintenance) but sometimes a boat just turns out to be a turd no matter how well maintained. No different than buying a car and getting a lemon.

One point in you note still puzzles me- why the PO was adjusting the fuel pressure regulator? These boats are FI so could be that the injectors are leaking by which can cause a rich idle if the temp sensor turns out to be OK. You may want to look in the throttle bore while at idle and at speed to see if they are both working correctly as well. These were used on tons of early chevys so you can look for ideas on the web there to get ideas. I remember one post where the injector was cutting out at high rpm due to loose wiring connection.

Good luck with your investigation and let us know what you find
Ross

The ECT (Engine Temperature Sender) with two wires ONLY sends signal to the ECM, not the gauge and your comment contradicts itself.

JimN
09-02-2013, 09:45 AM
Thanks JimN and Rossterman, sorry about the rant but I am so frustrated at the amount of time and money I am throwing at this boat. I do appreciate your replys!!

While the motor is a generic block, it is the Mastercraft specification / indmar electronics that seem to be causing the issues. I know these motors should be reliable which is why I bought one.

The Temp sender unit was replaced with a generic unit that was close to origional but not exact, so I replaced with an Indmar version. Boat does same with either Temp sender unit.

Melbourne does not get below freezing so I am not sure if the diaphram at fault. Started boat this morning on the verge and Oil guage is working again......? Might have to order a new MDC and guage pack.

Hose split at shower connection, plastic connection failed. Trans oil cooler checked and cleaned before it was put into the water.

We had an over fueling issue and the PO decided to take 3 turnes out of the fuel pressure regulater to try to reduce the overfueling. Now back to Standard

Checked code this morning = 44: (seen this one before and replaced MAF sensor)
Did not know if this motor has an O2 sensor.. Maf Sensor is new. Fuel Injectors are new, Fuel Pressure is 30psi across the range (approx at 4500rpm as it was hard to hold on at WOT and the motor popping and stuttering). Have run several tanks of fresh fuel, drained and cleaned fuel tank and replaced fuel filters, and cleaned fuel pump wire mesh. Cant understand Lean condition with black smoke out the back that smells like fuel.
Maybe the fuel pump is failing and is intermittant causing lean conditions then over fueling?
CODE 44
Trouble Code 44 indicates that the O2 sensor is showing a persistently high exhaust oxygen content (lean), despite the efforts of the ECM to increase injector on-time (thus increasing fuel delivered). Integrator and BLM numbers may indicate > 128 by a substantial margin.
The conditions for setting this code are:
no Code 33 or Code 34 (MAF Error) present, and
the O2 sensor voltage remains below 250 mVolts, and
the ECM is in Closed Loop control, and
the above conditions exist for more than 50 seconds.
Typical causes for this code include:
1) O2 sensor defective or lead shorted
2) Lean injectors (dirty or blocked)
3) Water in fuel
4) Exhaust leaks upstream of O2 sensor
5) Fuel pressure or volume too low
6) MAF sensor reading lower airflow than is actually present

Appreciate any ideas? Just not the one that suggests I take it into the MC Stealership....

Close doesn't work when electronic systems are concerned- the ECM is programmed to operate within specific ranges and if a sensor is outside of this range, you won't get what you're looking for. Being in Australia, you won't find OEM-spec parts as easily as we do, but I would think a Holden dealer could help you, since they're affiliated with GM.

I had forgotten that the fuel pressure regulator was altered- replace it. These aren't adjustable without the correct info or the rig for setting one up- you don't have these. It's vacuum-regulated to much tighter specs, not like the ones that can be added to a carbureted engine, where its not nearly as critical or accurate. You wrote that the PO adjusted the regulator by three turns and you turned it back- you may have put it back WRT physical position of the screw, but that doesn't mean it's regulating the fuel to spec.

You replaced the wrong part when you saw a code 44- download the codes and print them, so you don't continue to replace the wrong parts. If you had a manual, you could see the theory behind some of what's happening when the engine is running, the role of the senders/sensors, what to look for and the troubleshooting section for each area of the engine (Ignition, Control, Senders/sensors, etc). You also can't download just ANY code list- marine injection systems of your boat's vintage aren't closed loop. You don't have a MAF sensor or O2 sensor(s). If you were to google 'Indmar Predator engine', you would find some of the info you need.

You can't have a lean condition when black smoke is present. If it smells like gasoline and black smoke is present, it's either delivering too much fuel, or the fuel isn't burning completely. The ECT having high resistance would cause excessive fuel delivery.

I can understand being completely frustrated by the problems you're having with your boat, but:

-You complained about the shower hose failing- that was probably added by the dealer or the previous owner, not MC.
-The regulator was adjusted by the PO, not by a trained dealer or MC.
-You're replacing parts using what's referred to as a 'parts cannon' and working without correct troubleshooting info, training and diagnostic tools.

You're placing blame on MC when they had nothing to do with the problems. These engines are extremely reliable, the injection system is extremely reliable (the engines came off of the assembly only line needing a few accessories (raw water pump, fuel lines, marine starter/alternator, marine exhaust) and the harness that was designed for use in these boats, but the rest is all GM and its suppliers. There's almost no difference between this engine as delivered to Indmar and what went to Mercruiser, Volvo-Penta, PCM or anyone else. The ECM, harness, controller and programming were up to the shop that is owned by the person on the LT-1 high temperature technical bulletin and he definitely knows how to design, test, set up, program and troubleshoot these engines/systems and not only has he done development work for MC, he also did this for Indmar, GM and Delphi. He now does quite a bit for government agencies which place reliability above just about anything else, among others.

Anecdotally, I had a Chevrolet pickup with what's basically the same engine- 5.7L TBI and I never had any of the problems you are experiencing. I also don't remember seeing this set of problems in the time I have worked with boats/engines without some external cause, whether it was someone messing with a regulator when they didn't know what the he!! they were doing (the PO), mistaken diagnosis, incorrect parts or bad info. Personally, I would never have touched the fuel pressure regulator and I was trained to work on MC boats at the shop where the systems were designed, developed and tested, by the people who designed, developed and tested them.

You wrote that the injector spray looks good to the naked eye- use a timing light to see it better- it's like a snapshot when you check it this way. If it has any "tears" (meaning, gaps, like it was a torn paper cone) in the spray cone, you'll see it a lot more easily.

Rossterman
09-02-2013, 11:14 AM
The ECT (Engine Temperature Sender) with two wires ONLY sends signal to the ECM, not the gauge and your comment contradicts itself.

Jimn,
I think you are saying that that there is a temp switch, a temp sender, and a MEFI temp sensor as well? The switch has a single wire and is up by the thermostat at the front of the engine and screws into a horizontal opening. it causes the CEL/ alarm when above 181 degrees and the bimetallic switch closes the single wire link to ground (through the MEFI). This may affect other aspects of the engine operation- I'm not sure. This doesn't feed the temp guage ( through the mefi or directly) as is only open or closed signal. The second single wire sensor in the manifold that sits nearby and screws in vertically and feeds the temp guage. My temp temp switch was bad but ran boat for a week with the CEL and couldn't tell the difference in performance so believe it acts solely as a warning w/o affecting anything else (realize later models have limp mode to better protect engine but if a 2001 tbi does, mine isn't working).

The temp sender (2wire plug you refer to) provides variable resistance signal to the MEFI to tell iit how hot it is so as to adjust one aspect of the fuel curve map. If bad, it will cause engine to run rich. As said, There is also another single wire sensor in the manifold so that one must feed the gauge correct? So gauge could read fine showing the engine is up to operating temp but MEFI thinks engine is cold and dumps in more fuel than needed? Changing any of the single wire sensors won't fix the rich condition. He needs to check the sensor that has 2 wires and determine the resistance hot and cold then replace if out of spec

Jimn- is this logic correct?

Cheers
Ross

JimN
09-02-2013, 01:16 PM
Jimn,
I think you are saying that that there is a temp switch, a temp sender, and a MEFI temp sensor as well? The switch has a single wire and is up by the thermostat at the front of the engine and screws into a horizontal opening. it causes the CEL/ alarm when above 181 degrees and the bimetallic switch closes the single wire link to ground (through the MEFI). This may affect other aspects of the engine operation- I'm not sure. This doesn't feed the temp guage ( through the mefi or directly) as is only open or closed signal. The second single wire sensor in the manifold that sits nearby and screws in vertically and feeds the temp guage. My temp temp switch was bad but ran boat for a week with the CEL and couldn't tell the difference in performance so believe it acts solely as a warning w/o affecting anything else (realize later models have limp mode to better protect engine but if a 2001 tbi does, mine isn't working).

The temp sender (2wire plug you refer to) provides variable resistance signal to the MEFI to tell iit how hot it is so as to adjust one aspect of the fuel curve map. If bad, it will cause engine to run rich. As said, There is also another single wire sensor in the manifold so that one must feed the gauge correct? So gauge could read fine showing the engine is up to operating temp but MEFI thinks engine is cold and dumps in more fuel than needed? Changing any of the single wire sensors won't fix the rich condition. He needs to check the sensor that has 2 wires and determine the resistance hot and cold then replace if out of spec

Jimn- is this logic correct?

Cheers
Ross

The one-wire temperature sensor is for the gauge. The MIL (Malfunction Indicator Lamp/Light) which is sometimes called the CEL is triggered by the ECM, nothing else. RPM Reduction, which far too many take to be "limp home mode" is triggered by the ECT and controlled by the ECM, nothing else. RPM Reduction was introduced as soon as injection was added, but they may have used a bi-metal switch as a backup on the '93-'94 models- I would have to refer to my first notes and manual for later TBI to be absolutely sure. I don't remember being told about anything happening at 181F- overheat is triggered at 200F, although boats used in hotter locations can be recalibrated to avoid hot start issues when heat soak occurs. There's really no reason to add a switch and the associated problems that come from another sensor when the ECM is already programmed to perform these functions, other than a level of redundancy. Relying on one sender for voltage signal when the resistance could vary isn't the most fail-safe situation, but a bi-metal switch isn't infallible, either.

The logic is correct WRT actual temperature vs two-wire sensor's resistance, but it could fail with lower OR higher resistance, so low resistance would cause hard cold start problems, yet it could run fine at normal operating temperatures if the resistance is within tolerance in that range. If the resistance is too low, it would immediately go into RPM reduction. If the resistance is extremely high, it will run rich at all temperatures and be very hard to start when hot.

Again, I would have to refer to my notes and manuals to be absolutely sure about the temperature switch, but I seriously doubt that's causing any of the problems on this boat. Rich fuel ratio could be a combination of faults, too. Bad ECT and TPS or MAP sensor (or both), leaky valves/rings with extremely bad compression loss could all contribute but, unless the engine was abused, I don't think the cylinders/rings/valves are so bad although no actual proof has been presented.

Rossterman
09-02-2013, 03:43 PM
Jimn,
On my 2001 tbi motor there is a 1 wire temp switch for hi temp right near another 1 wire thermistor sensor for the guage. As you said, the one towards the front of the motor connects to the MEFI and sets a CEL for hi temp. The replacement has 181 stamped on it. Possibly on at 200 degrees and off at 181?

The other as you said feeds the gauge.

Didn't see the 2 wire sensor but probably down on the side of the block where it can't be easily seen. Here's a picture of the 2 single wire ones with the orange wire boots:

Mark rsa2au
10-10-2013, 05:47 AM
Ok, having run every possable electronic measurment mensioned on this and other forums ( and now the Indmar manual) I believe that all the current sensors on the boat are all within spec.

So far I have replaced both thermostats (origionals so replaced for insurance), the ecm temp sensor (faulty), and the impeller (insurance). The MAP sensor replaced (not sure if it was faulty) the throttle position sensor (bad readings), the Air Idle Screw (broken). This week I replaced the Knock sensor, and its connector as it was throwing a code.

The spark plugs, plug leads, distributer, rotor, and coil lead have all been replaced and firing order checked ok.

This week I replaced the fuel system. Fuel Filter, Walbro fuel pump (67 gallons per hour, and up to 90 psi), intank fuel lines and clamps. Also replaced fuel lines from the tank to the motor, and the return lines. Replaced pressure regulator and had the new injectors (30 hours) cleaned just in case. Installed fuel pressure guage and pressure sits steady at 31 PSI at all revs on the trailer (yes full throttle on water is the only real test).

Also pulled the valve covers off to check for broken valve springs, scored cams etc and can see nothing out of the ordinary. Also compression is steady across all cylinders.

Last thing to do is drain some oil from the motor as I have over filled it during the oil change I did. It's about 3 mm over the high mark on the dipstick.:confused:

Will be taking it out to the lake on Saturday for its final test, if it runs perfectly we keep it and I replace the MDC and/ or the guages as they have all sh@t themselves as well. If not.....:firejump:

I do note that my previous 4 boats ( 2 X Yamaha, Sea Ray and Malibu) required no parts replacement other than normal servicing while I had them. They started easily and ran perfectly for the 3 to 5 years I owned each. None of them ever let me down and they were older than 10 years when I purchased them. I purchased a Mastercraft expecting to have a higher quality & reliability but sadly either due to poor desighn, poor quality, or poor maintainence this has not happened. I hope after testing / repairing / replacing everything possible I might find that legendary Mastercraft quality and reliability.

Ps Thanks to all that have helped so far, I will let you know on Saturday... or look out for the smoke signals....

JimN
10-10-2013, 09:42 AM
Ok, having run every possable electronic measurment mensioned on this and other forums ( and now the Indmar manual) I believe that all the current sensors on the boat are all within spec.

So far I have replaced both thermostats (origionals so replaced for insurance), the ecm temp sensor (faulty), and the impeller (insurance). The MAP sensor replaced (not sure if it was faulty) the throttle position sensor (bad readings), the Air Idle Screw (broken). This week I replaced the Knock sensor, and its connector as it was throwing a code.

The spark plugs, plug leads, distributer, rotor, and coil lead have all been replaced and firing order checked ok.

This week I replaced the fuel system. Fuel Filter, Walbro fuel pump (67 gallons per hour, and up to 90 psi), intank fuel lines and clamps. Also replaced fuel lines from the tank to the motor, and the return lines. Replaced pressure regulator and had the new injectors (30 hours) cleaned just in case. Installed fuel pressure guage and pressure sits steady at 31 PSI at all revs on the trailer (yes full throttle on water is the only real test).

Also pulled the valve covers off to check for broken valve springs, scored cams etc and can see nothing out of the ordinary. Also compression is steady across all cylinders.

Last thing to do is drain some oil from the motor as I have over filled it during the oil change I did. It's about 3 mm over the high mark on the dipstick.:confused:

Will be taking it out to the lake on Saturday for its final test, if it runs perfectly we keep it and I replace the MDC and/ or the guages as they have all sh@t themselves as well. If not.....:firejump:

I do note that my previous 4 boats ( 2 X Yamaha, Sea Ray and Malibu) required no parts replacement other than normal servicing while I had them. They started easily and ran perfectly for the 3 to 5 years I owned each. None of them ever let me down and they were older than 10 years when I purchased them. I purchased a Mastercraft expecting to have a higher quality & reliability but sadly either due to poor desighn, poor quality, or poor maintainence this has not happened. I hope after testing / repairing / replacing everything possible I might find that legendary Mastercraft quality and reliability.

Ps Thanks to all that have helped so far, I will let you know on Saturday... or look out for the smoke signals....

At any point, did you measure the resistance from the ground at the rear of the engine to the negative battery post? Not the cable clamp, the post. If you see more than about .1 Ohm of resistance, you need to find out why. Do the same on the positive cable going to the starter.

Mark rsa2au
10-10-2013, 04:45 PM
At any point, did you measure the resistance from the ground at the rear of the engine to the negative battery post? Not the cable clamp, the post. If you see more than about .1 Ohm of resistance, you need to find out why. Do the same on the positive cable going to the starter.

Yep thanks Jim, I did this when I found the loose battery clamps a few months ago. I do not think the resistance was above .1ohm but will check again to be sure.

Mark rsa2au
10-12-2013, 02:14 AM
Yes!! Success At Last!!!!!

Took the boat out today and ran it hard for over an hour. Fuel pressure held steady at 32psi, and while we maxed out at 4500 rpm (new prop), there was no hessitation, no misfire spluttering, or farting. Pulled like a freight train.

I could hear the new fuel pump when running on the trailer but could not hear it when on the water.

No Codes either.

New prop is a 3 blade 12.5 inch diamter, 15 pitch. Runns easily to 45mph at 4500 rpm and wake is noticably flatter with no rooster tail out of the back. Even the kids noticed the flatter wake at 20 mph. Bad for our wakeboarders but we will fill the ballast bags for them.

Only issue was a nasty vibration from a full bore pull off, as if the prop was cavitating, but as soon as we picked up speed or backed off the power a little, the vibration went?

hewlett6621
10-12-2013, 05:10 AM
We'll done mate you must be over the moon after all the problems you have had. Summer is here early ,just go and enjoy.

Mark rsa2au
10-12-2013, 07:48 AM
We'll done mate you must be over the moon after all the problems you have had. Summer is here early ,just go and enjoy.

Thanks Mate! 3 weeks to Melbourne cup weekend, taking 4 days at Lake Eildon... cant wait!