Hi, I have a 7041544 Q-Jet on my '71 350. Carb. was professionally rebuilt about 5 years ago & has run flawlessly until this week. Only about 4000 miles on it. Engine was completely rebuilt to stock specs. one year or 1000 miles ago. I believe I have a choke issue but please let me know where to start. On cold start-up I set the choke with the pedal. Engine cranks for a few seconds & fires. Idles at high for a few seconds & then dies. Restarts after a few cranks & I can let it warm up. Any thoughts?
Sounds to me like the bowl is draining so it has to refill with fuel. The accelerator pump has some fuel maybe and is enough to get it started. Does this only happen when it sits for a while, overnight or longer?
I bet that is the problem if everything else runs fine. Bowl drains out and has to refill to keep running. It's not a huge problem, more of a pain in the rear. Probably would benefit from another rebuild in the future.
Mark, Where is draining from....cracked casting, bad valve....? I did notice a bit of gas smell in the garage. Wasn't sure if from the car or the kids leaving the gas jug open for the lawn mower.
Steve, Next time the car is cold, take the air cleaner off, push the throttle back by hand, and have a buddy crank it up. Willing to bet that the primary pulloff has given up, or needs a tweek. JW
Jim, That's exactly what my buddy said about it yesterday. He offered to look at it as I'm looking at a book of Greek when it's a carb.. I'll pull the breather tonight & have a general look see. Might be a simple hose connection too.
Steve, if you can get a vacuum pump and pull the choke open (cold) I think your looking for a 1/4" opening, AL.
Jim, Just swapped the pull-off with a new unit. Started the car from cold per my usual routine. Everything seems in order. Went to hi-idle & stayed there. Light tap on the pedal brought the rpm's down a bit. Another light tap brought it down to operating idle. Simple job to change the pull-off. Appreciate the on-line diagnosis. This is what counts, knowing what to do & what not to do. The slot used for the control rod on the old one has gradually been turned into an oval shape, over time with wear & tear. Cheers,
