Adjust throttle? VP4.3GL stalling

[birdpiper]

Engine: 1999 Volvo Penta 4.3gl
190 Horizon

The engine idles very low and unless it has been warmed up for about 30 minutes (giving it gas without prop engaged) it wall stall out while in neutral. Also, when I put the drive in gear I have to give it allot of gas or it will stall out. Once it is in gear it runs fine.

The issue has gotten progressively worse, the constant stalling makes maneuvering difficult (especially while docking!)

The high octane gas is new and the fuel filter has been replaced recently.

Can the throttle be adjusted and have higher RPMs while in neutral? If so, is this simple to do? Any other thoughts?

 

[Don S]

Re: Adjust throttle? VP4.3GL stalling

Sure, the idle speed can be adjusted, the problem is, why did it slow down that much to begin with. Was there any water in the filter? How long since the last tuneup? Have you done a compression test? maybe try adjusting the idle mixture?

 

[birdpiper]

Re: Adjust throttle? VP4.3GL stalling

Don, Thanks for the response.

I went ahead and replaced the oil filter and spark plugs to see if it was something simple. Everything looked good on the plugs and filter (no water), but the problem remained so I had a mechanic come out to the dock to take a look. He seems to think that one of the cylinders is not firing at idle. He removed and cleaned the distributor cap, but that did not solve the problem. He is coming back out to replace the distributor cap and cables. If that doesn?t solve the problem he wants to conduct a compression test.

The boat would not start at the end of last season. It turned out to be the relay (was able to diagnose and fix with the help of your electrical troubleshooting guide!). Could the new relay be causing this not firing issue?

Any other suggestions?

 

[Don S]

Re: Adjust throttle? VP4.3GL stalling

I went ahead and replaced the oil filter and spark plugs

I was referring to the fuel filter located under the fuel pump.

Could the new relay be causing this not firing issue?

No

 

[birdpiper]

Re: Adjust throttle? VP4.3GL stalling

Ahh yes, meant to type "I went ahead an replaced the fuel filter and spark plugs". Thanks for the feedback

 

[tk3c-pyce]

Re: Adjust throttle? VP4.3GL stalling

Unfortunately I don't know the way the engine idles (posting a video would be good). But generally what I would suggest is:
1) Cleaning the carburettor (take it off and soak it in gasoline or diesel or special agent)
2) Conducting the compression test (as advised)

 

[Maclin]

Re: Adjust throttle? VP4.3GL stalling

Does the owner's manual call for "high octane" gasoline?