Stalling after coming off plane

[Cootkiller]

I have a 2005 Volvo Penta 5.0 OSI-EF that stalls coming off of plane. I have had idle issues for awhile and just can't seem to nail it down. So far during the troubleshooting process I have had the boat scanned with no codes, replaced the IAC Valve, Throttle Position Sensor, Temp sensor for the ECU and the PCV Valve. I checked for vacuum leaks none found changed the plugs, fuel filter. I have checked the butterfly in the throttle body its good, what am I missing? The boat starts fine on the trailer as well as first start in the water, I am missing the warm-up cycle when cold starting the engine idles at 650-700rpms. Just a thought do you think it could be a stuck injector flooding the engine when I come off of plane as well as causing a rough idle, I could run some Seafoam through it with the small fuel tank I have.

 

[Don S]

Re: Stalling after coming off plane

You need to operate the boat and watch the scan tool to see what is happening. Don't just look for codes. The problem could be caused by a sensor sending wrong information to the ECM, but not something that would set a code.
But, before you do all that, what about the basics, when was the last time it had new spark plugs, cap, rotor, new fuel filter (and the old filter checked for water & contamination)

 

[Cootkiller]

Re: Stalling after coming off plane

I changed the plugs since the symptoms appeared about a month ago, the fuel filter was replaced after the symptoms, and the tech at the shop looked at the numbers coming off the scan tool and didn't notice anything out of the ordinary. Haven't replaced the cap and rotor, and I can't say when it was last replaced. I threw a lot of parts at it and I would like to narrow the problem down as much as possible before putting more money in without knowing if that will fix it.

 

[Cootkiller]

Re: Stalling after coming off plane

Anybody have any ideas?

 

[pvmtsux]

Re: Stalling after coming off plane

What does OSI-EF stand for? I'm with Don, sounds like you need to do a basic tune up first. Check the gap on those new plugs, pull your cap and rotor, replace the plug wires. I'd look into whats going on with the carb when the boat falls off. The butterfly might look ok but something is making her stall out. Too much or not enough air, fuel, or fire.

 

[Don S]

Re: Stalling after coming off plane

I would like to narrow the problem down as much as possible before putting more money in without knowing if that will fix it.

If I had the OEM service manuals for your engine, my diagnostic computer, DVM, fuel pressure gauges, compression tester, leakdown tester, etc. and the boat so I could test run it, I could tell you what was wrong. But to set here on a computer with only the the info that your mechanic said everything checked out and a list of the parts you replaced, is just not enough to make a proper diagnosis on an EFI engine of anykind.

 

[Cootkiller]

Re: Stalling after coming off plane

So I put a pressure gauge on the fuel line, and ran fuel system checks. Fuel pressure regulator working fine cleaned a little bit of debris off the screen. High pressure pump key on 58psi, running 50psi. Had the ecu reflashed/updated, but didn't fix the problem. A question I do have is concerning the specs on the low pressure pump, when key on pressure at 10psi, but key off bleeds the pressure down quickly is that normal? I can't locate the specs in my Seloc manual for the low pressure pump. So far the IAC,TPS,Temp for the ecu, PCV replaced, ECU updated Plugs changed, Fuel filter replaced, Fuel pickup checked and cleaned. Could the temp sensor on the exhaust manifolds cause any of my symtoms?