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skiknox
04-26-2013, 11:07 PM
95 ps 205 lt1 1:1 acme 541 only getting 3800 at full throttle. Don't have a GPS speed. Pushing on the stick seems fine up to 3000 then I have a lot of room with the throttle but ad as you drop it further rpms and speed just seem not to increase. Almost like the trottle cable isn't pulling like it should

j.mccreight@hotmail.com
04-26-2013, 11:14 PM
Something is wrong, you should be pushing close to ~4800rpm @ wot. What was your rpm's before prop swap?

skiknox
04-26-2013, 11:23 PM
Boat was need to me last summer and only pushed it to 4000 with stock 13x13 oj. Could it be trottle cable ?

j.mccreight@hotmail.com
04-26-2013, 11:31 PM
Maybe, anything is possibly, can you rev it in neutral past 3800, you can disconnect cable from throttle body and have operate throttle body and see if thats your issue.

blackcreek
04-27-2013, 10:25 AM
Boat was need to me last summer and only pushed it to 4000 with stock 13x13 oj. Could it be trottle cable ?

Pop off the air cleaner and push the throttle all the way open and you should see the throttle butterflies at perpendicular (90 degrees) or nearly so.
http://i616.photobucket.com/albums/tt245/MungieCake/TPIS%2058mm%20Throttle%20Body%20LT1/IMG_0115.jpg


My first guess on an LT1 not getting full power would be fuel pressure. The pump intake screen on the rear passenger side of the motor
tends to clog up if you don't have an inline filter installed before the pump. If the intake screen clogs bad enough it wipes out the pump and you get low fuel pressure. Check the throttle opening and the fuel pressure and if they are good you need to start looking at tps,fuel pressure regulator,clogged injector, ignition,compression etc. Fuel pressure is easily checked at the port on top of the motor. There are a bunch of youtube videos on how to check LT-1 fuel pressure and the indmar lt-1 is the same. Depending on load my 97 205 with the LT-1 pushes at least 45 mph and 4500 rpm on a stock 13x13 prop and the 1 to 1 transmission.

JimN
04-27-2013, 10:32 AM
95 ps 205 lt1 1:1 acme 541 only getting 3800 at full throttle. Don't have a GPS speed. Pushing on the stick seems fine up to 3000 then I have a lot of room with the throttle but ad as you drop it further rpms and speed just seem not to increase. Almost like the trottle cable isn't pulling like it should

You should hit 5000 RPM @ WOT- clean the screen and MEASURE the fuel pressure. Don't guess, don't hope.

If you have old fuel filter(s), change now. Also, make sure the fuel pickup tube is clear of debris and the anti-siphon is working properly and make sure the shutoff valve is fully open.

skiknox
04-27-2013, 10:49 AM
when I winterized I changed both fuel filters, the one that comes right off the tank and the one on the motor. I will look into checking pressure and check throttle body. thanks everyone for the tips.

skiknox
04-27-2013, 10:52 AM
hey JimN where is the shutoff valve located?

Table Rocker
04-27-2013, 11:13 AM
hey JimN where is the shutoff valve located?JimN is offline, so I will answer that one. The fuel shutoff is on top of the fuel tank between the tank fitting and the hose that goes to the 1st filter. It is an aluminum fitting with a short lever on top and the fuel line is attached to it. Move the lever back and forth a few times. In line with the hose is "open" and perpendicular is "closed". See what it feels like. If it doesn't feel like it is working right, it is easy to remove and inspect.

skiknox
04-29-2013, 07:33 PM
Well today I was going to pull the fuel pump and check the screen an figured I would put the fake lake in it first. Well lt1 ran full rpm range with me manually actuating trottle body and with the stick. The only thing I did prior to starting is making sure valve on tank was in on pos and it was but turned it in and off and couple of times. I guess I won't fully know until I get it back on the lake but it should run and diff should it?

JimN
04-29-2013, 07:44 PM
Well today I was going to pull the fuel pump and check the screen an figured I would put the fake lake in it first. Well lt1 ran full rpm range with me manually actuating trottle body and with the stick. The only thing I did prior to starting is making sure valve on tank was in on pos and it was but turned it in and off and couple of times. I guess I won't fully know until I get it back on the lake but it should run and diff should it?

I hate to rain on your parade but on the trailer, it can do fine but what's important is how it reacts when it's under load. I used to see the same thing and it was always a fuel delivery problem.

skiknox
04-29-2013, 08:10 PM
Well sh*t thought I might be in the clear. I guess pull the pump and check pressure is on the list again.

JimN
04-29-2013, 09:01 PM
Well sh*t thought I might be in the clear. I guess pull the pump and check pressure is on the list again.

Leave it in place when you test pressure but do it at several RPM- the way we were taught by MC, it should be checked at Key ON/Engine OFF, Idle, 2000 RPM and WOT. You don't need to go too long at those speeds, but you should test it while someone else drives or drive while someone else tests it. Write all results down, so you have a record of it in case something changes.

skiknox
04-29-2013, 10:24 PM
Some Jim are you saying I have to pressure test on the water under load to get a accurate reading? Or where you just say running it like I did can give you a false range of full rpms

JimN
04-29-2013, 10:35 PM
Some Jim are you saying I have to pressure test on the water under load to get a accurate reading? Or where you just say running it like I did can give you a false range of full rpms

It needs to be run on the water, in gear, at the various RPM. In neutral, running it means nothing and I used to try justifying what I found when I would call MC and they (Mark at MC, Monty & Mark at Indmar) finally got me to understand this. It's a PITA to have to take it to the water, but if the weather is good and you have the tools, parts and time, it's not a bad way to spend some time on the water. Take your anchor and a long enough rope, in case you need to replace something away from shore.

skiknox
05-03-2013, 01:28 PM
Removed fuel pump today and screen was clean and clear. Loaned gauge from auto zone and headed to the lake to get some readings.

mikeg205
05-03-2013, 01:49 PM
good luck...

skiknox
05-03-2013, 06:08 PM
Results
Fuel psi at key on 42
At idle dropped to 38
Through full rpm range 42-43
Boat runs smooth and no hesitation to 4000 rpms but that's it
Butterfly's on tb are opening all te way took filter off to comfirm
GPS speed was 41.5 wot

Thoughts???? I'm stumped

JimN
05-03-2013, 06:51 PM
Results
Fuel psi at key on 42
At idle dropped to 38
Through full rpm range 42-43
Boat runs smooth and no hesitation to 4000 rpms but that's it
Butterfly's on tb are opening all te way took filter off to comfirm
GPS speed was 41.5 wot

Thoughts???? I'm stumped

What's the diameter and pitch of the prop? If it's cupped and the pitch is excessive, it won't rev as high as it should.

Did you verify base timing by putting the ECM in diagnostic mode? A couple of degrees off can affect top end. I would put the timing light on it and check this, and leave it on so you can see total timing advance when it's being driven. If you don't see a major change in total advance, something is wrong. You should be at 10BTDC at idle and it should be rock steady. If it jumps around, there's nothing wrong, but it's not in Diagnostic Mode. Use a paper clip as a jumper for terminals A and B on the ALDL (Diagnostic Port, at the rear of the engine- ALDL stands for 'Assembly Line Data Link). Do this with the engine off, start it and manually maintain 1000RPM when you check the timing. Set it to 10BTDC, snug the distributor hold-down, re-check/reset to 10 if it moved and tighten it. If it's off by 1, don't freak out but try to hit the number. After shutting it off, remove the paper clip and cover the ALDL before running it again.

The paper clip can also be used to read codes on the check engine light.

skiknox
05-03-2013, 08:10 PM
Thanks Jim
The prop is a brand new acme 541 13x12 this is out there but would over torqing a prop nut do anything??? and all the other stuff you mentioned I didn't check that's a bit over my mechanical ability and tools. I do have a buddy that's a good car mechanic and has diagnostic equip so he might be able to help.

mikeg205
05-03-2013, 08:25 PM
I had the same thing with my 95 PS205 - 41.5 is about top speed - I only got to 4200 with my 3B OJ legend and now get 4800 rpms on my OJ Force 4B... Try a different prop...if you can... just my .02 - sounds like everything normal... I wonder if tach is 100% if your hitting 41.5 - Rated speed on that boat/moter is 43 iirc.

skiknox
05-03-2013, 08:54 PM
My manual says with lt1 should be 47mph and 5000rpm wot

JimN
05-03-2013, 09:22 PM
Thanks Jim
The prop is a brand new acme 541 13x12 this is out there but would over torqing a prop nut do anything??? and all the other stuff you mentioned I didn't check that's a bit over my mechanical ability and tools. I do have a buddy that's a good car mechanic and has diagnostic equip so he might be able to help.

The prop nut wouldn't cause anything like this.

If your friend knows injection, have him check the TPS, MAP and ECT (coolant temperature sensor).

Verify that the spark plug gap is correct. Insufficient spark intensity will reduce power.

This is TBI and not LT1, right?

skiknox
05-06-2013, 11:41 AM
it is a 95 LT-1

skiknox
05-08-2013, 09:23 PM
Anyone know I good indmar mechanic particularly lt1 around Knoxville? I know America boat center is the mc dealer but would like to see if there are any other options?

JimN
05-08-2013, 10:26 PM
Anyone know I good indmar mechanic particularly lt1 around Knoxville? I know America boat center is the mc dealer but would like to see if there are any other options?

Just for grins, look at the crank position sensors- if they look like they have metal shavings covering the sensors, remove that and see if it changes anything.

Other than fuel pressure, what has been changed recently? Did you change plugs, are the plug wires original (if they are, they're WAYYYYYY too old). Did you check/clean the battery terminals, ground terminals on the engine?

skiknox
05-09-2013, 10:21 PM
Ran boat again today with the factory oj 13x13 boat ran 4200 at just below 40 on GPS. I did notice a rough shakey spot and a faint miss in rpms around 1200.

skiknox
05-09-2013, 10:22 PM
Ordered new plug wires and going to change plugs and see.

Mark rsa2au
05-09-2013, 11:54 PM
Let us know if you find a solution.

I have checked and changed everything except the fuel pump & filter (next on list), but I still cannot get the revs above 4200 with out it misfiring / backfiring. Somedays it will run to 4500rpm / 42mph and stay there on 3/4 throttle but stutter / mis etc on full throttle. Pulls like a steam train up to 4000rpm though, above this is where the challenge is!

CC2MC
05-10-2013, 12:13 AM
Sounds similar to what mine did, except all I got was 35mph. It was my fuel pump and I just cleaned it out and now I get 44.9mph.

JimN
05-10-2013, 12:30 AM
Let us know if you find a solution.

I have checked and changed everything except the fuel pump & filter (next on list), but I still cannot get the revs above 4200 with out it misfiring / backfiring. Somedays it will run to 4500rpm / 42mph and stay there on 3/4 throttle but stutter / mis etc on full throttle. Pulls like a steam train up to 4000rpm though, above this is where the challenge is!

Can you run it at night, in the dark? You would want to remove the engine cover for this but it's more loud than unsafe (unless someone tries to stick their fingers in the belt and pulleys. Look for arcing between the plug wires- I think I mentioned them before and I would bet they're not insulating the way they should. Cross-fire will cause exactly what you're describing.

Mark rsa2au
05-10-2013, 12:48 AM
Can you run it at night, in the dark? You would want to remove the engine cover for this but it's more loud than unsafe (unless someone tries to stick their fingers in the belt and pulleys. Look for arcing between the plug wires- I think I mentioned them before and I would bet they're not insulating the way they should. Cross-fire will cause exactly what you're describing.

Yep, ran it in the dark, (Scary at 40mph in the dark, but know the lake and did a slow cruise down first) no arcing. Replaced the plugs, plug wires, distributer & rotor. Used dielectric grease on all joins (not contacts of course). Have also removed all earth contacts and cleaned and replaced where necessary. No Change. Fully charged battery.

PS have also replaced, map sensor, TPS, idle controll valve(faulty), injectors(buggered), temp sensors (all 3), checked earth resistance and wired new earth lead to compare - no difference. Fuel pressure is as per manual at idle, and 2000rpm -sprung a leak at 3000 but still looked good, fuel was spraying over the motor by then so no test at 4000rpm and above.

JimN
05-10-2013, 12:52 AM
Yep, ran it in the dark, (Scary at 40mph in the dark, but know the lake and did a slow cruise down first) no arcing. Replaced the plugs, plug wires, distributer & rotor. Used dielectric grease on all joins (not contacts of course). Have also removed all earth contacts and cleaned and replaced where necessary. No Change. Fully charged battery.

PS have also replaced, map sensor, TPS, idle controll valve(faulty), injectors(buggered), temp sensors (all 3), checked earth resistance and wired new earth lead to compare - no difference. Fuel pressure is as per manual at idle, and 2000rpm -sprung a leak at 3000 but still looked good, fuel was spraying over the motor by then so no test at 4000rpm and above.

Ant testing of the Ignition Control module? Make sure the base of the distributor is clean and making GREAT electrical contact to the block- that's where it gets its ground reference, not any of the black wires. Also, make sure the IC module is grounded to the distributor body. In addition, make sure the spring clip on the rotor is making good contact with the center electrode.

Did you write that you verified base timing at 10BTDC in Diagnostic Mode?

skiknox
05-12-2013, 05:36 PM
Got new Taylor wires and plugs just finished putting them in and I think I found the culprit! I know it's obvious but when I fogged in fall last year plugs looked pretty good.

skiknox
05-12-2013, 05:40 PM
Wires are very nice 8mm taylors got info from a member posting on here they are from inboard online. The ones I had were Packard electric marine seem to be smaller maybe 7mm.

thatsmrmastercraft
05-13-2013, 12:00 AM
Got new Taylor wires and plugs just finished putting them in and I think I found the culprit! I know it's obvious but when I fogged in fall last year plugs looked pretty good.

That would do it.

skiknox
05-15-2013, 11:39 PM
Ran it today with new plugs and wires ran much better close to 44 on GPS at 4600 rpms I'm happy with that!!! I've heard of some better numbers with lt1 but this thing pulls hard.

thatsmrmastercraft
05-16-2013, 12:29 AM
:woohoo::woohoo::woohoo: