Hey guys I'm working on a 95 F-SUPERDUTY with Automatic tranny for my step dad. It has had what I would consider a rough surging idle for quite awhile but ran just fine. Well recently when you fire it up it misses something horrible if you rev the crap out of it for awhile it will come out of it. I got two codes off of it one was I'm trying to remember here high low voltage on #3 injector and the other one I can't remember something to do with #3 i think also.

So I'm planning on installing a new one tonight in #3 or am I missing something???? the sensor on the drivers side head when I unplug it it defently changes the idle but I wouldn't call it better or worse (even when it's not missing). I'm thinking that the #3 injector is either sticking or the solenoid is on it's way out.

And of course I will check all valve cover harnesses for issues.

Any advice is helpful!

 

On the rough surging idle you may want to look into the IPR mine was bad and caused that

 

Well I pulled it in the shop last night thinking it might be more related to the IPR because it would intermittently come out of it some and then quickly revert back to running like crap. So I pulled the fuel bowl out took the IPR out fulley dissembled including taking all plungers and needles and spool valve out and cleaned there was some build up but not much. Reinstalled no change... Crap...

Then started pulling harness plugs out of RH VC pulled both plugs off no change! Damn thing was only running on 4 cylinders! ultimately found #2 glow plug connector burned to a crisp shorting the entire front plug out.

But that still doesn't explain the problem with #3 so going to put new harness in and try it before changing #3

Wish me luck

 

A burned harness will cause the truck to shut down that bank to prevent more damage. Hopefully a new connector will fix your problem. How are you numbering the cylinders, as 2 and 3 would be on different banks. 1-3-5-7 are the passenger side, 2-4-6-8 are the drivers side.

 

Well tore into it farther found both harnesses bad replaced both sides last night running much better also tested glow plugs found one bad one each side had some used ones that were still good from doing a job on a buddy's 02 so couple freebees there!

but I'm still not completely satisfied with the way it sounds idles a lil rough and maybe I'm just used to my 03 but still. Also if I flat foot the pedal just sitting there in park the engine rev's to about 2000 then kinda pauses then up to say 3000 pauses then red line kind of like it has to think about it for a second?? Is that normal on these older trucks??

 

That pause at 2000 sounds like injector orings. That may be why its idling a little rough too. How's the fuel in the filter look?

 

Fuel looks good also has new filter. It almost seems to me like it's the hpop kicking up?

 

Generally with a pause/stumble at or around 2k on a free rev is a sign of orings going bad. How many miles on it?

 

About 165000 work truck miles Don't bad o-rings cause hard starting? This truck has always started quite well.