Random Reving

[DaveBr]

My truck will randomly rev for a split second like someone gave the go pedal a quick shot. This has been going on for a few months now. Today it did it twice. Both times the truck was idling in gear. Could this be the last days for the PMD? or is it something else?

Cheers

[DaveNY]

Same thing been happening with my truck for 8 or so years since Ive had it.
feels almost like some one bumped you at a light or the truck just pops in and out of gear very quickly.
I have replaced PMD for an unrelated failure and that little quirk is still there very infrequently,so I just live with it.
I have seen threads that others experience the same Phenomenon, I do not think it is a serious issue.
Dave

[DaveBr]

Time to give this thread a bump. The matter is getting worse. Bouts of spastic reving repeatedly going on. It stops when I let my foot off the go pedal. Some days it's fine but others it becomes quite a rodeo. Any thoughts?

[sctrailrider]

Might need to get some contact cleaner and clean all the wire connections & the ground points before winter gets here....

It does sound like a PMD symptom, might wiggle the harness around and see if you can make it rev while you are wiggling the wires, may be loose somewhere....

[DieselDavy]

The foot pedal is a potentiometer. Could it be that the "pot" is dirty and now intermittent? This could cause a intermittent reading of wide open, idle or anywhere in between.
I've never looked at the schematic of the thing but some of the brands (probably all) use dual "pot" so that they can detect dirty segments of the "pot" and set a code.
Hoping someone else like "DMav" or "More Power" can jump in here and comment.
Dave

[DmaxMaverick]

The foot pedal is a potentiometer. Could it be that the "pot" is dirty and now intermittent? This could cause a intermittent reading of wide open, idle or anywhere in between.
I've never looked at the schematic of the thing but some of the brands (probably all) use dual "pot" so that they can detect dirty segments of the "pot" and set a code.
Hoping someone else like "DMav" or "More Power" can jump in here and comment.
Dave

Not the APP (pedal). It has 3 independent circuits. Any of the 3 failing will set the STS (Service Throttle Soon) lamp and code. 2 failing will set limp mode, and 3 failed won't respond at all. Even if only intermittent.

[DaveBr]

I have no codes. What are the possibilities it is IP related? This is really weird. I have a remote pmd and a known good pmd still attached to the pump. I will plug in the one on the pump and see what happens.

[DaveBr]

It was cold this morning and the colder it gets the worse the situation becomes. Seems to resolve itself as it warms up. It was so bad this morning she finally went into limp mode. I pulled off the road and restarted it and all is well. I'm scratching my head.:confused:

[DaveBr]

I plugged in the original PMD on the IP and the situation seems to have resolved itself. I will repost in a week to give it a fair test. Supposed to snow here on Tuesday.

[DaveBr]

Problem fully resolved. It was the FSD. I don't think I heard of one going south with these particular symptoms. It was a Dtec remote mounted.

[Yukon6.2]

Hi Dave
How long did the Dtech last?Months KM's?
Any comparison to previous FSD's in longevity?

Thanks Thomas

[DaveBr]

It lasted less than two years. The Stanadyne on the pump is older than that and still works. However you can't make a decision based on one case. I will replace it with another Dtech and we shall see how it goes.