1fastC3

I drove my car (77 4spd) today for about 100 miles when I get off the expressway I put it in neutral and it drops down past the normal idle speed and seems like its going to die, I rev the engine until I got home to keep the car from quiting, when I do get home I checked everything out and it appeared to be ok, fired it up, it idled for about 10 seconds then died. The whole top end is new and I have not had this problem before, any ideas on what could be wrong?

-alex

txsilverado

My first thought is something may have worked it's way into the idle circuit of your carb. It may need to be cleaned. Before you take it apart, check to see if you can adjust the idle back up with the idle screw. I have seen the idle screw back out over time and cause the engine to idle too low and die. That would be an easier fix.

cchristo

Bad fuel filter?

BTW, noticed your CC (or is it now AC) patch. I used to be the SMI at UCLA.

1fastC3

I'll check out the idle adjust screw and the fuel filter only has about 300 miles on it.

-alex

Roughrider

There's the possibility it could be the sock filter on the sending unit back in the tank. After all these years, it could be getting clogged.

1fastC3

I pulled one of the plugs and it looked like ****, one of my buddies who works at a speed shop suggested it and also said I may want to look into getting an MSD box and how it cleared up fouled plug problems he had seen and experienced before. thanks for your input guys.

-alex

l8279vette

Is it a holley carb.? If so take air filter off,while it's running look in carb. see if boosters are dripping fuel.If they are the power valve is shot.

1fastC3

its a Barry Grant Speed Demon 750 electric choke with vacuum secondaries, the carb has maybe 8 hours of total run time.

-alex

l8279vette

I'm not that familar with the demon carbs.But i think it has a power valve so check it ,also check your float levels.Check the air filter base see if it has gas stains .

cchristo

It might, but it's just another expensive band-aid approach that won't solve the underlying problem.

frostbitten09

I have hte same problem with my quad. i set my idle screw in and it only dies and stalls when i drop into gear... but it will idle in park.... I have to get a new hose for my pcv valve, it was broken so the pcv inlet on the carb was wide open... i dont know if thats the problem yet.. I also just replaced my electricle made it better but not gone... let me know what you do to fix it

dmaaero

Did you try adjusting the idle screw? On my new rebuild i was checking the carb to see if it was opening all the way, engine was not running, when she warmed up it wouldn"t idle i assumed linkage sliped when i held gas pedle to the floor for someone to check carb opening. I idle it up with the idle screw not another problem. That 750 may require some adjustments to stop the plugs from looking like black.

1fastC3

it runs a little rich at idle, as for the idle in general, I looked at the idle adjust scew and have a few other ideas of potential problems, can't really check them out now, but the whole weekend is open.

-alex