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Old 09-02-2013, 09:45 AM
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JimN JimN is offline
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Originally Posted by Mark rsa2au View Post
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?
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.
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