Engine Idle

[Richard Phillilps]

1988 GMC Sub 2500 7.4 L  idles a little off. Just put in a remanufactured engine. New map, new computer, new coil, new matched injectors, added 1 inch spacer for the TBI, cleaned TBI, new cap and rotor, new plugs, new egr new ign wires, new harmonic damper.  Starts right up but the idle just doesn't seem right. Plenty of power.  Start up went well, 2100 rpm for twenty min.  Timing 4 BDC with the thingee unplugged. no vaccum leaks

I have a new distributor but have not installed it.  

Someone else had a similar issue, but I could not find if they had a solution.

 

 Thanks,

Richard

[Logan Lanfear]

I believe that these trucks had a sensor that controlled the idle on the passenger side of the TBI intake.  The sensor can be rotated to adjust idle but sometimes it has to be clearanced.