Volvo Penta 5.7Gxi engine misses above 2500 rpm

[JimmyD1966]

I had a new 5.7GXi-f long block installed one year ago. When I start the engine up it misses when the rpm gets about 2500 rpm. The interesting thing is after 30-45 minutes it disappears and is fine. I've replaced the distributor cap, plugs, and spark plug cables but still not fixed. very frustrating...any insight would be appreciated

 

[alldodge]

Re: Volvo Penta 5.7Gxi engine misses above 2500 rpm

I had a new 5.7GXi-f long block installed one year ago. When I start the engine up it misses when the rpm gets about 2500 rpm. The interesting thing is after 30-45 minutes it disappears and is fine. I've replaced the distributor cap, plugs, and spark plug cables but still not fixed. very frustrating...any insight would be appreciated

:welcome: to iboats

Was this a new or remanufactured engine?
If reman, do you trust the engine rebuilder where you got it?
What weight of oil are you using?
What are your oil pressure readings at, idle, on plane and after coming off plane back to idle?
Do you hear any kind of a tick while it's running before it starts running fine?

 

[bajaunderground]

Re: Volvo Penta 5.7Gxi engine misses above 2500 rpm

How long has this been going on? Does it do it all the way to WOT or only at/about 2,500rpm? Does it only see to do it when cold/just Starting up? Maybe EFI computer has an issue in "cold operation" until it gets warm?

Check all electrical connections for continuity and all fuel lines/filters for flow...if after running for a 30-45 minutes it runs "fine" maybe some electrical connections need to be heated up for proper connection or a restricted fuel line expands enough to allow proper flow (doubtful, shot in the dark)?

 

[JimmyD1966]

Re: Volvo Penta 5.7Gxi engine misses above 2500 rpm

Thanks for the help. Answers to your questions are below

:welcome: to iboats

Was this a new or remanufactured engine? New from Volvo

If reman, do you trust the engine rebuilder where you got it? As much as you can trust Volvo

What weight of oil are you using? Not sure. I just had an oil change done by the marina but not sure what they used.

What are your oil pressure readings at, idle, on plane and after coming off plane back to idle? I can't remember the pressure exactly (will check next time I'm at the marina) but at idle the needle is half way on the gauge and at full throttle it's pretty close to the maximum reading (slightly less than max)

Do you hear any kind of a tick while it's running before it starts running fine? No ticking, but some squeeking which sounds like the belts need to be adjusted.

 

[alldodge]

Re: Volvo Penta 5.7Gxi engine misses above 2500 rpm

My questions were coming from a posability you may have had some clapsing lifters, now I don't think that is the problem. Now maybe a sensor is the issue until it warms up. Need the Volvo guru's to comment here. Is it carb or EFI and what year is your boat?