73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: Jakethesnake73 on March 25, 2017, 02:19:23 pm
-
After i drive down the highway against the wind the truck drops in idle when i stop. Also i have my idle at 800ish when i hit the gas really quick from a stop and let off it wants to die or does die. I have a new fuel pump and filter. Could this be a carb issue? Im thinking its more related to plugging of the in tank screen. It runss great oherwise
Sent from my SAMSUNG-SM-G891A using Tapatalk
-
I would look at your linkage, it sounds like it may be hanging up and not fully dropping off the high idle cam. At least that is where I would start.
-
transmission?
is the 800 rpms set at cold?
year, make and model?
-
Other possibilities are weak idle solenoid, worn throttle shaft bore, poor state of engine tune....
-
I have the opposite issue most of the time. Sometimes the idle will drop, but it usually just keeps building up as I drive, it'll start at 750 warm, then after 10 minutes of traffic it will be at 800, then 900, then 950, then I have to shut it off in gear or it will diesel, and even then sometimes it picks up enough to diesel in gear although that's rare. The timing is at 2° advance, new distributer, old quadrajet. The carb is likely the issue in my case as I can adjust the idle mix screws with no change until either the throttle opens and closes or I shut it down and restart it.
-
I have the opposite issue most of the time. Sometimes the idle will drop, but it usually just keeps building up as I drive, it'll start at 750 warm, then after 10 minutes of traffic it will be at 800, then 900, then 950, then I have to shut it off in gear or it will diesel, and even then sometimes it picks up enough to diesel in gear although that's rare. The timing is at 2° advance, new distributer, old quadrajet. The carb is likely the issue in my case as I can adjust the idle mix screws with no change until either the throttle opens and closes or I shut it down and restart it.
i would be looking at a vacuum leak. prob the base plate at the carb or even the throttle bushings
-
Irish, I just put a new carb on this weekend and it seemed to have solved that issue as well as many others. It picks up a little idle speed still, but not near as much.
-
if youre sure theres no vacuum leaks i would set timing and make sure your vacuum advance is hooked up to manifold vacuum and working