Hi all,

I have a carb question. I need help. I have 70 Mustang 351c. It has a Holley 650 4bbl.

I let the car sit from 1998 -2003, and then got it up and running and have been driving it ever since.

It seems that when I start the car, the idle really hunts and surges. It will flucuate from 400rpm to 800rpm. Sometimes it will cut out, then it becomes hard to start. I let it warm up, and it will do the same thing at stop lights until I have driven it for about 10-15 miles. Then it idles ok. Not so much hunting. It will vary between say 600 rpm and 850rpm.

A couple of times the car has backfired through the carb. The good thing is, once it backfires through the carb it runs spectacular. The idle is steady at 900rpm, no stammering off the line. Smooth acceleration.

Here is my question: When the carb backfires what does that mean? I realize the fuel isn't being burned or mixed, but which is it?
Is the carb on ts last legs?
Could my fuel line be clogged?

Is there a danger of fire?
Is it something else?

The motor and carb are about 8 years old total. I had the motor tuned about 6 months ago - that is when this problem started. It ran fine for awhile until I let the car sit for about 2-3 weeks between drives.

Help!

Brustang