4.3 volvo engine putters

[wiegs]

I have notice that sometime when I turn the engine (4.3 carb 190hp) off it keeps running and putters for a bit then finally stops. Any idea why this is?

 

[fossill]

Re: 4.3 volvo engine putters

It's called "dieselling".
Common causes: too high idle speed...most common, carbon build up on pistons causing a hot spot, timing off, spark plugs wrong heat range...too hot, rich idle mixture setting.
You want to correct asap or risk possible water ingestion into the engine cylinders.

 

[wiegs]

Re: 4.3 volvo engine putters

wow, that is a lot of possibilities. The engine temp is good, so I wonder if it is the plugs or timing. I may try mid grade gas to see if that helps. I was running WOT just before I pulled into the dock and the engine was running for 2 hours plus.

 

[fossill]

Re: 4.3 volvo engine putters

Yup, a good tune up should take care of all of them.

 

[Bondo]

Re: 4.3 volvo engine putters

I was running WOT just before I pulled into the dock and the engine was running for 2 hours plus.

Ayuh,... Let it idle a couple minutes,....

Dieseling will turn the motor, into an Anchor, Quickly...

 

[wiegs]

Re: 4.3 volvo engine putters

The engine was probable idling for a couple minutes by the time a coasted into the docks. Im going to put higher grade gas in for this weekend. I will also let the boat idle longer before turning it off. If it continues, I will take it in for a tune up. With only 70hrs Im surprised that is needed. Hope it doesn't turn into a money pit.

 

[Bondo]

Re: 4.3 volvo engine putters

ooops,... edit...

 

[wiegs]

Re: 4.3 volvo engine putters

Ok so I finally got the book out. First off the 4.3carb requires 89 or better octane fuel. I have been using 87. Also says the idle rpm should be 550-650 in forward gear. My idle rpm is 1000. Seems like the idle rpm is high. Can I adjust that somehow?

 

[Bondo]

Re: 4.3 volvo engine putters

Ayuh,... Back off the idle adjustment screw...
It's on the side of the carb, at the end of the throttle cable...

 

[wiegs]

Re: 4.3 volvo engine putters

Will that impact my wot rpm? I just got a new prob and the wot rpm is perfect at 4500.

 

[Bondo]

Re: 4.3 volvo engine putters

Ayuh,.... It's the Idle adjustment screw,... Not the WOT adjustment screw...

 

[wiegs]

Re: 4.3 volvo engine putters

sorry dont mean to be a complete moron but there are about 3 screws in the area around the throttle cable end. Any more specifics. I have posted a pic.