Idle problems after carb rebuild

[astuckey]

Hi, I have a 1988 Gm 4.3l. that I just rebuilt the carb on. I rebuilt it because the acceleration was bad, and we weren't getting very high RPMs. Anyway, since I put the carb back on, I have had the following problems. At first, it took some time to start, but after a few days, that problem seemed to go away. The other problem I am having, is bad idle, primaraly when cold. Regardless of choke position, when the engine is cold, it will idle slowly, and slightly rough. (around 400 RPM) Also, it is not overly responsive when in this cold slow idle. If I move the throtle to get it to anywhere over 600, it runs perfectly! Both idle screws are set to 2 turns out, which seemes to work the best, and was recommended by the rebuild kit. I would just adjust the idle screw on the throttle, however, it idles at a smooth 600 when warm. (And when I say warm, I mean anywhere above about 145) Any help would be greatly appreciated!

Thanks

 

[LAC_STS]

Re: Idle problems after carb rebuild

Look in the FAQ. There is apart where it describes setting the idle mixture screws on the carb and setting the timing.

You need to set the screws. First turning one in until it stumbles then out till it stumbles counting how many turns it takes for each. Then split the difference. And also you need to make sure your timing and all is set right. Just to be sure.

Also maybe spray soome carb cleaner around the base of the carb and see if the engine stumbles. Did you use a new gasket to attach the carb to the intake?