JMD

But usually when a car runs this way, it is a vac leak..... I know you have checked for leaks outside the crankcase, but there might be one inside.

There is very little margin for error when installing gaskets on SBF's with aftermarket heads and intakes. It is NOT enough that the bolt holes line up, careful placement is a necessity.

kalli

ya, the issue is described is 100% vac leak, if the PVC didn't help see what happens if you spray down brake cleaner or WD40 along the lines of the inteke gasket while its running. if rpms go up or down. same with carburetor gasket.
Try as well with the hand blocking most of the carb if that changes anything. if you can get it to idle then or better it's some internal vacuum leak i'd say.
and JMD made a good point there with the gaskets. but usually if they're off you have water problems (at least I had).

JMD

The third time was a charm for my son and his 302 powered Falcon with aftermarket heads and intake....

This wasn't because he was careless but because the area where the gasket had to be was very thin.

IMO it would be possible for there to be an intake leak inside the valley cover where the traditional means of testing are ineffective.

Red hot exhaust manifolds/headers are another prime indicator of a big intake leak...

SuperHoss

Sorry for the long time between posts but the problem was found two weeks ago and I now have a temporary fix on it (that has it running like a champ). Even though I checked the grounds, bypassed the resistor and put a full 12 volts to the coil, checked the coil, replaced a lot of stuff that was in good shape (intake and carburetor gaskets, PC valve and hose, distributor cap, and the rotor), and saw to some stuff that needed maintenance (carburetor, plugs, and wires) the problem persisted.

The replacement module in the distributor was actually the source. I took the old module and "rigged" it where the wobbling (broken) post would not move, installed old module, fired it up with very little hassle, and turned the idle screw back to its normal position. Amazingly enough it ran pretty well after setting up for 9 months and having old gas in it. It was a little groggy when I started driving it but it came around without any trouble.

kalli

well ... glad you got it sorted, I would have never thought I once had a car with a ground issue on module and there the problem was when engine load was changed. vac advance moved baseplate, ground there, no ground. I would have never called the module to be the problem if it runs nice 1000+

SuperHoss

The only conclusion that I can draw is that the new module was defective. One of the connection posts on the old module cracked and would vibrate with engine and changes in advance; which caused the initial problem that showed up at any speed or RPM. I checked and rechecked all of the connections (and instructions) for the newer one and everything was hooked up properly, but it still refused to idle.

I used some wire insulation and tie-straps to hold the post on the old module in place so it's not pretty, it was aggravating to install it back in the distributor and not hit anything, but it solved the problem. I'm sending the faulty module to Accel in order to see what the problem was (out of curiosity) and get a replacement that works.

Hmmmm...being that the Billetproof line has been discontinued I may use this as an excuse to get a new distributor. Sounds like a plan.