I bought my '95 auto back in March with 278K on the clock. Now I have 282,xxx.

It has a lopey idle. It's not real bad...it's not getting worse but it is there. NO other symptoms at all.

I have put in a new overflow valve. I just did my KDP and put on a new harmonic balancer. (I didn't expect the balancer to fix anything but the old one's rubber was hard and cracked).

Anyway the truck has plenty of power for being stock and runs smooth while accelerating and cruising. My boost and egt gauges show nothing out of the ordinary. It just has the lope at idle.

So I am wondering if it could be injectors starting to go south. I am certain they are stock and original.

I have not yet checked the valves so they may be out...but I would think they would create more noise if they were far enough out and not cause it to idle funny.

 

What is your idle speed. I know it sounds like a simple kind of question, but that may be part of it. I know aftermarket injectors can cause a lopey idle, my 97 does, but only when its really cold.

 

It idles right around 750 +-. It doesn't fluctuate really at all.

It does it in park, neutral and in gear.

 

Hmm.. The only thing I would check then would be fuel pressure possibly. If its bone stock I have a hard time believing it is governor related.

 

Sounds like a gov issue to me. They usually do that when the governor wears... (not P-Pumps specifically, just injection pumps in general) But check the fuel pressure to be sure.

 

http://www.cumminsforum.com/forum/94...-12-valve.html

 

I think I am just going to go ahead a replace the lift pump.

I know I could check the fuel pressure but the truck has 282K on in and I don't know the service history so for $100 it's worth it. It may be the original.

if that doesn't fix it I will have the injectors tested next.