Chev. 350 rough idle & eng. loads up and quits.

[AltonR]

Still battling problems with my 1985 Cobalt Chevy 350. Previously I had the standard ignition changed to electronic and the 4 barrel carb overhauled. Today I Pulled plugs and all were wet & black with carbon. Replaced ignition wires and put in hotter plugs. Set the timing to 10 Degrees BTDC and leaned & adjusted the idle to maximum RPM. Engine surges, over loads and quits. Oh yes! I drained all the old gas (emptied fuel/water seprator - no water) and put in High Test. Im stumped! Any ideas? Thanks!

 

[CharlieB]

Re: Chev. 350 rough idle & eng. loads up and quits.

What model and serial, what carb?

Float too high or blown power valve will run too rich at and just off and idle, loading up plugs and killing the engine.

 

[ziggy]

Re: Chev. 350 rough idle & eng. loads up and quits.

maybe go back to square one. compression test so ya know ya got something to work with.
tuneup. using the proper parts. like the right spark plugs. and setting the timing to spec. which best i can see is 8*btdc. replace fuel filters. replace cap and rotor. get it all set to specs. if the problem still persists, then move to fuel systems. carb. could easy be your problem as it's already been gone through it sounds like. but now you don't know whether it's ign. sys. or fuel sys. to approch. that's why i think start from square one and confirm everything is set to and within spec.....

 

[blousteau]

Re: Chev. 350 rough idle & eng. loads up and quits.

I agree with Bubba1235, you are running way to rich. Don't blow your money on stuff we know is working, fix the fuel overload first.

 

[Silvertip]

Re: Chev. 350 rough idle & eng. loads up and quits.

Start by looking at the choke. On a stone cold engine it should be closed. Warmed up, regardless how the engine is running, it should be wide open. I suspect this is where the problem is.

 

[AltonR]

Re: Chev. 350 rough idle & eng. loads up and quits.

Thanks for the help! My Carb is a Rochester Quadrajet Model#1324 as near as I can locate on the throttle body. Other longer # is: 17059286. The butter fly opens as the engine warms. I replaced the coil and distributer cap in an tune up one year ago. Haven't found a fuel filter other than the water separator. Hope this helps narrow things down. Rich

 

[JustJason]

Re: Chev. 350 rough idle & eng. loads up and quits.

there should be a fuel filter inside of the mechanical fuel pump, there should also be 1 inside of the carb fuel inlet.
Set your idle timing to 8btdc, in neutral check that it advances properly.
head up to the "Adults only" section and check out how to check a boats fuel syste.
After you've checked that, or even before it doesn't really matter because you need to do both. Check your engine compression.
If the compression and the boat fuel system check out then it's probably time to rebuild your carb.

Oh and another thing... get rid of theh "hotter" plugs and go back to MR43T's

 

[AltonR]

Re: Chev. 350 rough idle & eng. loads up and quits.

What's so frustrating is I expect the engine in the boat to run smooth like a car engine. A Chevy V8 with 500 hours should be barely broken in. I have been sorely disappointed so far. If my plugs are fouled and wet and the engine floods out. Shouldn't the conclusion be that too much fuel is being delivered thus elimenating fuel blockage at the filters, carb. and fuel pump Is it necessary to rebuild the Carb to adjust or unstick the float. Rich