Weird engine issues

[Jshock]

So I was adjusting timing today and using it to set my rpm after overhauling my carb (an edelbrock 750 performer w/ electric choke) and I noticed that after playing with the throttle that the rpm wouldn't return back to my 850 it would stay at like 1100. Checked the cable and its loose. Checked with vacuum gauge and vac is normal. Sprayed around all intake areas for vac leaks with carb clean and no changes. Pressed on linkage and idle dropped back down. Raised rpm and it stuck again until I pressed linkage. Then the rpm went all erratic and it died. Now it won't restart. Checked for spark good. Made sure it still had gas (no gauge) good. This ones got me stumped! Help please! Engine is a semi built sbc 355.

 

[Jshock]

Oh man I forgot to mention. I pulled out a spark plug and it looked oil fouled. The threads were a tad wet too. Slight smell of fuel. I know to change the oil tomorrow so I don't wipe bearings but I'm a tad scared and not sure where to proceed. The linkage has me stuck too

 

[Jshock]

Nothing? No ideas? Come on you guys are geniuses! Someone's got an answer

 

[crotchss]

Try checking the choke to make sure it wasn't on a little bit, keeping the idle speed up slightly. If it was up slightly and on the choke and you turned out the idle screw to slow it down then "blipped" the throttle it may slow it down low enough not to idle. Also what is your base timing set at?

 

[Jshock]

Choke full open at operating temperature. Base timing at 10 degrees. Was thinking of putting it to twelve but then had those issues. I'm at a loss unless I had a head blow but I saw no signs. No coolant or anything. Idk I'm stumped

 

[foxtrot]

You must have a vacuum leak or the choke cam is bound up holding the throttle open.

 

[Grandprixpaul]

Sounds like the fast idle cam on the carb may be stuck in the wrong position. Check to make sure the set screw is in place on it,if its set wrong it will idle high or low.

 

[Jshock]

Well thanks guys ill check the vacuum again today after I do the oil change and il look into the fast idle cam. So correct me if I'm wrong but the setscrew for the fast idle cam is supposed to line up between the two marks right? Although I've had this car and a carb for 14 years now I still haven't completely figured em out. So much for ASE certs they don't teach you about carbs anymore ..

 

[foxtrot]

If it is a vacuum leak causing the high idle you possibly won't see the issue on the vacuum gauge. The leak could be between the manifold and carb or the head.

 

[Jshock]

I was spraying carb clean all around the base of the carb and the manifold gaskets and the heads wih no change in rpm. Normally if there's a leak it'll suck the flammable in and increase rpm. But keep the ideas up I am gonna check them all!