rough idle?

[sniekamp]

318 in a 74 dart with a 2 barrel carb. Exhaust choke coil.


Okay so her are my symptoms, start the car and it starts off fine. Pulloff works good (checked it). But after it runs for about 5 seconds it idles a little rough, doesn't die though. Then when I put it into gear, reverse or drive, and step on the gas or acts like its about to die and almost stops running, then acts like it gets a bunch of gas and takes off. I was wondering about why its idling rough and what causes the hesitation when I hit step on the gas? Also this is only when the car is started. Once i? drive around the hesitation doesn't happen and everything runs real smooth.

 

[KitCarlson]

Check the vacuum pull-off that opens the choke slightly when the engine starts. The pull-off can develop a leak, or the linkage can get twisted and stuck.

 

[sniekamp]

I have checked the pull off, that's what I thought it was too. But there is no leak in the vacuum pull off :/.

 

[KitCarlson]

There is a setting on the pull-off by bending the U in the linkage. I think it should open the choke about 1/8". May want read a manual or carb kit instructions on the setting and measure method. It may also be that the choke setting is too lean.

You may also have a weak ignition system, or other problem.

 

[Snake]

Heat cross over in intake gummed up with carbon

 

[BillGrissom]

My 69 slant acted like that for years until I finally got a carburetor that made it run unbelievably smooth. I think all the others (Holley 1920) were making it idle lean. There are many bad rebuilt carbs out there. I don't think the cross-over would affect it much if it still happens in hot weather. My accel pump was OK. Indeed, I had to give it a short squirt when leaving a stop light or it would tend to die. If you really want to know what is going on, install an O2 sensor with a lean/rich box or go big and get a wideband O2 sensor.