418 Stroker - Opinion on fuel problem please?

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69CudaFormulaS

69CudaFormulaS

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My freshly built stroker is intermittently running really bad then really good. Oil is fuel fouled after only about 40 miles. Smokes (blue) when runnng bad, then seems to clear. I am not a mechanic but not an idiot either.

A float is stuck or something causing too much fuel to be dumped into the intake?????

Will fuel damage the rings if it is washing past them and out the exhaust?

Any help or suggestions for tests I can run to diagnose?

Dont think it matters but this is a 418 stroker .040 over, forged crank and ross pistons 10.5:1, W2 heads, hyd roller cam, Single plane intake and Holley 850.
 
That thing should fly when it's all sorted out.

Do you have a fuel reg on the car? what is it set at?

I would try another carb if there is one available. If that fixes it, then yours needs a rebuild, something isn't right with it. It isn't a tune issue, as it is intermittent.

Yes, the ring seal can go away on you if it keeps washing them down. Sounds like it is dumping a lot down too!

-Kenny
 
yea washing the cyl down with gas can ruin a set of rings and the finish of the bore...

as said check fuel pressure and float level? im guessing electric pump but if mechanical is the diaphragm leaking into the engine??

give us more info on like fuel pressure, part conditions, what were you doing when it started running bad...
 
A little more about the running bad also. Is it coughing or backfireing? also make sure the choke (if you have one) isn't shutting and opening on you.
As a rule of thumb...black smoke is fuel
blue smoke is oil
white smoke is coolant
and green smoke is : your burning money :angryfir:
 
Also check that you have the right power valve. If it is opening early it will dump fuel down the carb throat under light load. You may be able to see this at idle by looking down the throatm when it idles. Check it in drive if it is an automatic. Use a vacuum gauge at idle while in drive. Check the reading. Make sure the power valve is 1.5 to 2 steps lower than the vacuum reading you measured.
 
Thanks, will check it out in the AM. Also put in new fuel tank, new Carter super-mehanical pump, new fuel filter. Choke working OK. Will check vacuum and pressure.
 
not sure what oil is fuel fouled means but blue smoke is oil consumption not fuel if its fuel it would be black water would be white. from what you have wrote i would check the pcv valve make sure that it is baffled correctly and not pulling a bunch of oil. or posibly intake manifold leaking. just a guess.
 
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