Volvo penta 5.0 GI PEPS not going over 3.000 rpm

[Andrecosta]

I've read a lot of topics with the same problem and had tried much of the solutions proposed on them, but my problem doesnt seem to be solved.

I have a 2000 chris craft with a twin 5.0 volvo penta GI ( throttle body injectors). The starboard engine runs good, but the port side engine doesnt what to raise rpm. It goes fine all the way to 2.000 rpm, but after that it struggles to gain more rpm, if i " pump " tha throttle is goes slowly to 3k rpm, but if i mantain the throttle, is goes back to 2k 2.2k rpm. And i can hear couple backfires when im trying to " force the engine ".

Parts i have already replaced or switched with the other engine:
- spark plug
- spark plug wires
- distributor cap
- distributor rotor
- fuel pumps ( whole assembly)
- fuel tank ( switched lines with the other side )


What im thinking to try next is check ignition timing and injectors.

Anyone have any hunt on what i should try?

Video showing what is happening

Thanks

 

[Bondo]

Ayuh,..... Welcome Aboard,..... Sure sounds like a fuel delivery issue,.....

What's the fuel pressure on that motor,..??

 

[Andrecosta]

I didnt check the fuel pressure because i dont have the gauge. How do i check the high pressure on a tbi injector? I dont have the fitting to check it

 

[dypcdiver]

Here are the fuel pressures.

 

[dypcdiver]

You might like to watch this TBI overhaul.

 

[Andrecosta]

Found it guys, it is on the TBI, but not sure exactly what is, i will do a completely tune up and injector cleaning.

Swapped tbi between engines and the problem went to the other engine, so we found where it is. One advantage by having 2 engines.

Do you guys think i should buy new injectors or just clean an test those ones?

Thanks everyone who helped!

 

[alldodge]

You can have the injectors cleaned and flow tested by a "marine" facility. Don't have it done at a auto shop because they may not test it under high rpm

That said most likely the injectors will need to be replaced. If you do get replacements, don't get them from ebay or Amazon, you want New not reman. Onces on ebay and amazon are junk. You cannot remanufacture a injector

 

[Andrecosta]

Just to close the topic, got all the TBI cleaned and the injectors cleaned on the ultrasom machine for 2 hours, installed back and the boat is running good! Thanks for everyone help

 

[Monterey296Twin5.0Gi]

Just to close the topic, got all the TBI cleaned and the injectors cleaned on the ultrasom machine for 2 hours, installed back and the boat is running good! Thanks for everyone help

Just noticed your thread. We had a similar problem with one of our TBI 5.0Gi motors, it was like a dead spot in the power and we could get past it on occasion and get up to 3000rpm. It first happened when I came off the throttle too quickly, and then wouldn't throttle back up. Mechanic that came out ended up saying it was the oil sending unit on that engine, hard to believe, but we have a new sending unit and the problem hasn't come back. FYI.