For the last four or five days I slowly, but steadily developed a rather annoying idle surge. Almost a stumble that got to the point that I though it was going to stall at stoplights, though it never did.

So yesterday at lunch I popped the hood in the parking lot at work intending to look at the IPR, and discovered the wiring connector for the fuel heater had come unplugged. Plugged the heater back in and the surge is gone....all the rest of yesterday and no trace of it still today.

I'm not sure how the fuel heater being deactivated could cause an idle problem, especially on a warm engine on an 80 degree day....anybody care to speculate?

 

Just for grins, could you disconnect that fuel heater wire again and see if the surging returns?

I can't see the correlation.

Pop

 

Probable indirectly related. I'm guessing it wasn't the fact that the fuel heater was inoperable, but more likely because some part of the PCM that monitors that connection was seeing an "open" and responding with some kind of default value to some table. Just a guess...

 

I did, and it didn't. I have not driven it again with it unplugged, and it did take a few days to manifest itself the first time. I'll take it for a ride this evening and see if anything happens.

 

Hmmm, did you touch the IPR plug at all? Even the smallest bit of corrosion in the contacts for various sensors can make the ECU go wacky. Moving it would have cleared the connection and restored drivability.

 

Oh, and another thing. Don't you have a chip? It's not working loose at all is it?

 

Maybe the IPR plug....Don't think I reached in that far, but who knows. Couldn't have done anything beyond just bumping it if I did touch it. Definitely not a loose chip.

 

Sometimes even tugging on the wiring harness is enough to move things.

 

Evidently that was enough.....idles smooth as a baby's behind, and I CND the problem, so I'm calling it fixed.

 

Old aviation saying:

"Problems that go away by themselves, come back by themselves."

Pop

 

Indeed, but with no more symptoms to troubleshoot there's no where for me to go....until they return.

 

Yea, that's what we used to tell the pilots, too!

Gives 'em a warm, fuzzy, feelin' of confidence! ;-)))

Bwaa ha ha!

Pop

 

We tell our pilots the same thing. Stroke their ego's a little bit and they're fine.

 

COOKIE88. Im not sure if this will help you but here goes.on my truck I went thru the same type of problem, and I pulled acode up and one of the codes was icp sensor. and I ordered one and put it on and that fixed the erratic idle and stalling.. my truck only acted up when it was really and fully warmed up. colder weather the problem never showed up. I noticed on the package that the icp sensor came in








COOKIE88, hi I had a similar problem on my truck.erratic idle and some stalling.I got a new icp sensor #pf6tz-9f838-a for $95.45 from powerstrokeshop.com and that fixed my problem. on my truck it only acted up when it was completely warmed up. hope this can help you. and thanks for your help on my question about the wiring on my aic problem. 01psd

 

Thanks for the part # 01psd. I'll keep it in mind if the symptoms return.