318 Troubleshoot

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thejohnnyguy

thejohnnyguy

Young Gun
Joined
Oct 7, 2010
Messages
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Location
Charlotte
Symptoms:
Starts up (usually have to hold my foot to the floor)
The choke revs her up and all's well...
She comes back down to an idle and things get kinda rocky...
It idles half decent for a little bit then sounds like its running very lumpy, as if a few cylinders flood out and eventually it shuts off.

I'm just wanting a few suggestions as to what the problem may be if you guys have any guesses... I do plan on borrowing a timing light and checking the timing. Do these symptoms sound related to being out of time?
 
Two BBL? pull the fuel line at the carb,take the brass fitting out that screws into the carb,dont lose the needle that is in the fitting.Check to see if any dirt or varnish is in the seat.Clean with carb cleaner-spray.Replace fitting with needle intact,replace fuel line.If not-post again
 
Checking the timing is a good starting point. Then again, it could be so many other things causing this. Just make a checklist and keep crossing stuff off as you troubleshoot.
 
d5667 said:
Two BBL? pull the fuel line at the carb,take the brass fitting out that screws into the carb,dont lose the needle that is in the fitting.Check to see if any dirt or varnish is in the seat.Clean with carb cleaner-spray.Replace fitting with needle intact,replace fuel line.If not-post again
Click to expand...

4 barrel edelbrock 600cfm. recently rebuilt the carb. it still seems to drip a little when I shut the engine off though...
 
Can't see it from here but sounds like you have your floats set too high.Did you rebuild it or someone else?
 
Sorry,I gotta go.Run your jet screws in snug then back them out two and a half turns each.That should get you in the ballpark,when you check your floats,make sure your seats are tight-no trash in the seats-all screws are tight.Let me know
 
d5667 said:
Sorry,I gotta go.Run your jet screws in snug then back them out two and a half turns each.That should get you in the ballpark,when you check your floats,make sure your seats are tight-no trash in the seats-all screws are tight.Let me know
Click to expand...

Thanks i'll give that a shot. Which screws do I adjust though? are they the 4 screws near the bottom? or are you referring to the idle mixture screws?
 
Forgot to add that I recently pulled the plugs and cleaned them as they all had a black soot-like coating.
 
Lowered the floats a little, I may have been 1/8" off... re-adjusted the idle mixture screws to 2.5 turns out. Can't test it today though, I work from 1 - 10 so I gotta get ready. after work I'de piss too many people off with the noise (living in apartments sucks) So Wednesday being my next day off I should have a timing light and knock it all out then! I'll keep ya posted!
 
Ok;don't sound like a timing problem,may be out a little but more of a flooding problem.Make sure that your choke is letting off after it warms up.Later
 
Choke should be all the way open after it warms up and if it leaks gas into the intake after its warm and you shut it off then it sounds like heat soke. Edelbrocks are known for that, they make a heat sheild plate to put under them to help with that problem.
 
plymouth67 said:
Choke should be all the way open after it warms up and if it leaks gas into the intake after its warm and you shut it off then it sounds like heat soke. Edelbrocks are known for that, they make a heat sheild plate to put under them to help with that problem.
Click to expand...

Just looked into that, Only thing is that this happens before any heat really builds up. Happens after maybe 15 seconds of running... I'm hoping the float adjustment fixed it. Makes sense that if it was filling up too much and fuel was spilling into the intake that it would flood. As for the choke, I'll check that Wednesday when I can roll her out of the garage and fire her up. I've set off too many carbon monoxide detectors at this apartment complex already... :p they're very sensitive.
 
No go.... Damnit!
Start her up, Choke's bringing RPMs up as it should, Down to idle and it slowly dies. I get out and look at the carb and it's still trickling gas from the round thingy... I'll get a pic and illustrate... Also the maintainance guy stopped by and said it may be related to the vacuum advance??? He crazy? or could this be the case?
 
He crazy. Vacuum advance only comes into play on acceleration. "the round thingy" is this a new technical term? Maybe your idle adjustment is too low.
 
Sounds like you have too much fuel pressure at the carb or something in the needle and seat.
 
Round thingy = Venturi booster, sorry... lol to me it's the round thingy... I had the vacuum advance in the wrong inlet and the correct one was capped off, I switched them, ill try again tomorrow. Also it used to run great when the fuel tank vent was plugged off with a bolt, I took the bolt out you think it's relevant? I'll plug it up and try again tomorrow. I'll also get a FP gauge and check it... Ive checked over the needle/seat situation multiple times and they're brand new... *sigh*
 
UPDATE: Saved by Mr.Gasket's in-line fuel pressure regulator. No more issues in that department, Now just gotta set the timing, get new belts, and see how comfy she is driving around the complex. Hopefully have her out on the road soon! im getting eager!
 
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