Bandit60

I am not technically proficient so what I say is second hand information from a very accomplished tech. The car is a 70 442, 455 four speed. Edelbrock Q jet carb. When starting the car cold the choke is actuated. Due to fuel evaporation to get it started can take a while. With the choke actuated it will start and high idle. When you use a quick acceleration on the engine the car will not back off to low idle. You can lightly touch/push the counterweight and it will back off to low idle. With the engine warmed up it will start and go to low idle immediately. The carb has been off the car lubricated and checked and appears normal. We are mystified why the carb will not back off to low idle when warm and the throttle quickly applied. What else can we do to sort this out. The tech has a ton of experience with Q jets and is mystified.

Sugar Bear

Is the choke blade completely open meaning exactly straight up and down when the high idle cam will not drop?

Had this once, it was the linkage on the side of the carb that moves the idle cam up and and down. Was going crazy and older experienced tech saw a shiny spot on the linkage, turned out that was the problem spot. Relieved the friction and problem was gone.
Good luck!!!

joe_padavano

Well, the first problem is that Edelbrock Qjet carbs are calibrated for Chevy motors. In your case, either the choke isn't adjusted properly or the linkage is binding somewhere. The fact that the engine goes to low idle when warm is a further suggestion that the choke is working properly but the coil just isn't adjusted correctly. This is trial and error of moving the choke coil one notch toward lean and trying it, Keep doing that until you go too far then go back.

Bandit60

Sugar Bear and Joe. Thank you for your insight on this QJet. Our problem is solved using both of your suggestions. It now works as designed.

Sugar Bear

Glad you got it working, go drive it a lot!!!