Question about intermittently loading up/running rich.....>>>>>

[Johnny SixPack]

My 496 stroker was warming up the other day and next thing I knew is went from idling smooth and strong to gasping and barely keeping an idle of 200 (normally idles in neutral @ 1100).

I knew I wasn't out of gas, but put 4 gallons in just to be safe, but it didn't help.

What began to happen is that when you shut the car off (remember, all this was happening when the car was totally cold) and restart it, it would run like a champ for no more than 30 seconds, and then it would go back into the asthmatic routine. You could shut it off and restart it all day long and it would consistently follow that pattern (engine temp did not seem to effect the issue).

Tried revving it up while it was running OK in the hopes that I just had some bad fuel in the carb, but no love.

Then I took it to a shop today it seemed to magically fix itself.

The mechanic still decided to check the float bowl (was at first overflowing when the screw was out), adjust the idle and check for vacuum leaks, as we were still getting a little bit of blue smoke.

But his guess (and the only other option I had in mind) was that something small enough to get past the fuel filter, but small enough to keep the carb's needle valve from seating, had made its way into the carb, and with all the tinkering/revving was able to work it loose.

He recommended a fuel system cleaner, and said to keep an eye/ear on it.

Anyone else here had any similar problems, or have a better guess?

'Cause, as I've been told, engine problems don't fix themselves, they just show up later.

Thanks in advance!


Johnny