I have a k1500 4x4 manual with a 4.3 in it. For some reason while in 1st and 2nd gear, when I press the clutch in and come to a stop, the idle drops really low as if it were to die, but then come right back up. No engine light, and hard to diagnose myself.

Any input?

 

Does the truck bog getting out of first gear also?

 

Sometimes. Timing has been a pain. Factory setting is at 0 degrees, but my truck dies at 0, so I have it at 4, and is running really rich.

Sorry for not replying for a bit, I figured no one knew what it could be.

 

I'm not expert by any means but it sounds like it could possibly be the mass air flow sensor. I still get the same problem

 

what year is it?? TBI or port injection??

I would remove the idle air control motor and clean the pintle and air passages for starters.