I've got a problem I was hoping someone could help me out with. After I've been driving for a while and I’ve gotten up to normal operating temp (205-210) if I stop at a stop light it starts to act like it's starving for fuel and wants to sputter out. I have to keep the RPM's up to keep it running. If it does die it acts like it was flooded. I don’t have any problems on the highway when staying on the throttle. Just when it’s idled for a little. I mean a stop light or two, not standstill traffic or long periods of time.

For example this morning I drove to the gym. From the house till I got off the highway it ran great (2 stop signs and wide open road). After I exited, I hit 2 stop lights and one stop sign. When I pulled into the parking lot it started to act up. I killed it and went in to workout and once I got back in, it started up just fine like nothing ever happened. But once I got back into my neighborhood it started to act up again. I pulled into the garage, put it in park and let it run for a little to see if it would stall out…nothing. Put it in gear…nothing. I can’t seem to recreate it at home. I could be wrong but it only seems to do it when the engine is under a load.

I've got a high performance cam (300/312), 13:1 compression, and alot of other goodies. Used to have a mechanical fuel pump but once this started happening I changed to a Holley blue elec pump. Still wants to stall out. This is driving me nuts...I can't seem to figure out what is causing it. Any ideas????

 

I assume the compression listed is a typo? What carburetor do you have and have you checked the float levels? What temperature thermostat do you have? Is there a fuel return line anywhere in the system? Did the mechanical pump have a return line?

 

I have had this problem pop up every now and then, never found out what it really was, but I bumped the idle up to 950 and it seems to solve it most of the time.
I suspect that the carb gets overly hot, and would like to try a carb insulator to see if that fixes it.
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No typo on the comp. The carb is a quik fuel 850 and the thermostat is a 185. No return lines now or before with the mech. pump. Could that be the problem? Have not checked the float levels. How do you? Could it be the timing? I'm at a loss. Any of you engine guru's have any ideas? I can provide more detail as to what all is on the engine if needed.

 

Happens to me when I don't let the engine warm all the way in P. When put in R or D, RPM goes down from 700 in P to 600ish in D (with lights on, 550 or so) and it feels like it wants to stall. Setting the idle speed screw higher seems counter productive if it's SUPPOSED to idle at 600 with or without a load while in D.

Long and short, I feel your pain. Nights where I put car in N at long stop lights just to get an extra 100 RPM for peace of mind. Not sure what causes that problem though.

One problem my mechanic did fix was a rough idle that would cause the body to shake. Apparently there was oil gunk clogging one of the spark plug annodes. Maybe that is what causes the RPM to drop? I don't know.