very low idle sometimes

[coolinit]

I hope someone can help me. My truck is a "92" 4x4,3/4 ton

manual trans. w/3. 55 gears & stock for the most part. My problem is that it idles fine sometimes and other times it drops down to 3 or4 hundred rpms. I can sometimes stomp the fuel peddle quick and it will fix itself,sometimes not. I've replaced the fuel filter and the transfer fuel pump thinking it was getting weak & not putting the correct pressure to my injector pump while idleing. It didn't solve my problem. The truck runs great other than the idle. If anyone can lend a thought, me and my truck would be thankful.

 

[Evan A. Beck]

First, make sure the throttle lever is sitting on the idle stop. Also, check the operation of the KSB solenoid and cold idle switch. On a cold start, there should be 12V at the soleniod until it warms up. If there is no power there, replace the temperature switch in the intake manifold.



If all the above checks out ok, it could be an internal injection pump problem. Seen this one a few times before... It's not a big deal to take care of, the pump just needs to be removed and sent out to a good pump shop. I have seen a lot of VE pumps in need of a rebuild, and crappy idling is one of the symptoms that rebuild time is near. Rebuilds are fairly inexpensive. Or you can always upgrade to a 3000 RPM 230 horse pump from BD...