Please help!! 4.3l lx mercruiser

[jimmyw]

Someone please help me I am at a dead end. I have a 1988 mercruiser 4.3l lx. I am having trouble keeping the motor running. It will idle but alittle ruff. as soon as i give it some trottle it stalls out. thought it was the carb so I just got a rebuild carb. I have a new manual fuel pump. i have checked for cracks on the intake manifold. and made sure the gasket of the carb is on properly. I just dont know. Someone help me. thanks

 

[Steph_RS]

Re: Please help!! 4.3l lx mercruiser

Check:

-Ignition Timing
-Spark plug condition
-Spark plug wire condition
-Cap/Rotor
-Be shure your rebuilt carb is calibrated for an 4.3 (Main jet ,etc...)
-Be shure they have no air leak between intake and head , intake and carb) Use Break cleaner or something like that all around this part , if the rpm goes up , you have a leak somewhere.

 

[JustJason]

Re: Please help!! 4.3l lx mercruiser

have you started with a full tune up including all fuel filters yet?

 

[jimmyw]

Re: Please help!! 4.3l lx mercruiser

thanks I have replaced the fuel filter, wires and the cap but I will check to see if I have a leak. If I do have a leak any good advice to fix besides a new gasket

 

[Bt Doctur]

Re: Please help!! 4.3l lx mercruiser

Compression test with the throttle wide open and post the results.
Try a remote tank with new fuel.
What condition are the tips of the spark plugs

 

[JJJ]

Re: Please help!! 4.3l lx mercruiser

If the fuel is old and stale it can also do what your symptoms are. How old is your gas?

 

[JustJason]

Re: Please help!! 4.3l lx mercruiser

Thanks I have replace the fuel filter, wires and the cap

Did you just change the fuel water seperating filter? Did you get the filter inside of the fuel pump, and the filter inside of the carb? How about the spark plugs and the rotor under the cap too? Did you double check to make sure the ignition is timed correctly? Theres more to a tune up then 1 filter, wires and a cap.

 

[BOB2009]

Re: Please help!! 4.3l lx mercruiser

Does It Have Thunderbolt Ignition? If So Check The Quick Connect Plug That Goes Into The Unit. Pull It Out Check The Pins Make Sure They Are Clean And Make Sure It Clips Tight Back Into Place, Vibration Could Shake That Baby Loose.let Me Know How You Made Out.

 

[jimmyw]

Re: Please help!! 4.3l lx mercruiser

Thanks again to all. I did some checking this weekend and the distributor cap is good and clean on the inside so are the plugs. fuel filter and filter in the carb was changed. just put fresh gas in the tank. I start it and the motor runs great when idling but as soon as you give gas it stalls. i will try the timming next. again thanks to all.

 

[jimmyw]

Re: Please help!! 4.3l lx mercruiser

ok timming is good. Just on a guess i removed the cable connected to the trottle and gave it trottle at the carb and it worked great. but then i noticed after running for a min or 2 that the carb started to overflow and gas was comming out of the accelorator pumb and the entire carb was covered in gas. any ideas anyone. its a rochester 4bb carb. thanks

 

[searay3]

Re: Please help!! 4.3l lx mercruiser

There is a problem with the float inside the carb. If you bought or had it rebuilt, you may be able to call them back and get some help. If it were mine and rebuilder won't help, I would buy a carb kit, float, etc and rebuild it again. Rebuilding carbs does not always work. Once it's apart you will be able to see whats what in there. If you can't/won't take the carb apart, I would buy new. Less chance of body deterioration and new carries a warranty against defects.