Stuck at full throttle

[Fogel]

I have a 1996 K2500 6.5TD Auto Trans. The only mods to it is a 4" exhaust. I was pulling a trailer on the freeway up hill. I went to pass a slower moving semi and found myself rapidly gaining speed with no pedal effort. After pulling it home I attempted a restart and the same occured - wide open and then it shut down all with no pedal effort. Finally I put my Solus on it (KOEO) only to find the engine load at 100% and no DTC's. Is it a possible APP sensor or............. Any help would be appreciated! Thanks

[Yukon6.2]

Hi
Sounds like a PMD failing.The same thing happened to my brothers truck,had more power at the time than any other time driving it,Installed a Dtec remote mounted driver and cured it.If you have a extra driver try swaping them and see if it cures it.
Good Luck
Thomas

[JohnC]

Problems with the app should set codes. You can monitor the three controls and see what they are doing with the scanner.

More likely the PMD is shorted or the fuel solenoid is stuck.

[Robyn]

What you describe is a less known failure of the PMD.
There is a circuit that burns through and the beast goes wide loose.

Full tilt until the ECM senses overspeed then it trips the fuel shutoff solenoid to stop the runaway.

Replace the PMD and your issues should go away.

I have seen two of these type failures. Both were when I was testing a handfull of used PMD's I got from the local Stanadyne repair shop.

It does get exciting for sure.

Saw one down town one day too, later model Burb galloping around a parking lot doing brodies and smoking the tires and rolling some serious coal.

Get a fresh DTECH PMD with a new resistor and remote mount if you already have not done so.

If you dont know what resistor is in the thing, a 5 will keep it happy.


Good luck

Missy

[Fogel]

Hey guys, thanks for all the help. I will replace the PMD and the resistor with a 9. The PMD is remote mounted but I am thinking of removing it from the engine bay. I found a supposed "buulet proof" one put out by Stanadyne http://www.hdiesel.com/product.asp?id=42. That's supposed to address this issue in particular. We'll see what happens and I will keep you posted. Robyn thanks for your insight and knowledge.

[Robyn]

IMHO
Between you, me and the dust on the floor, I would forget about the Stanadyne PMD and use a DTECH. It will plug right into your existing cable.

The DTECH has a real good track record.

The New Gray Stanadyne requires changing the wiring harness to the IP.

I will admit, that after all the years of failures and BS with the Stanadyne stuff, I simply dont trust them one little bit.


Good luck

Missy

[Fogel]

This was definately the problem. THe truck runs sweet now. BTW, the one that failed was a Dtech. Thanks Robyn!

[Robyn]

Now thats news. :eek:

Have not heard of any DTECH units failing.

Glad that the rig runs fine now.

Robyn

[Yukon6.2]

Hi
Robyn i posted my failed Dtech weeks ago:eek:.i was told of other failed ones at that time.Seems like they are just another electronic gadget that will fail like all the rest.I was really pissed about mine because the truck gets little use,less than 3000 miles.Plus mine was acting up right from new,i was fooled into chasing problems because i assumed it wasn't the Dtech.I now have a used stanadyne and the truck runs great.I will install my warrenty Dtech when it arrives,because i want to get as much use as i can befor the warrenty is up.
If you have a PMD/FSD on your truck no matter what make keep a know good one as a spare
Thomas

[racer55]

Around the various forums there have been a lot of reports of failing Dtech or flight systems pmd's in the past couple of months,the most common failure as reported above is "going all toyota"or uncontrolled racing of the engine.

[Robyn]

This is not a good thing.

Best to let DTECH know that this is what happened so that they can fix the issue.

The DTECH is better Potted and the components are rated for a higher temperature before failure.

The overall design is about the same though.

I do know that the original PMD from GM/Stanadyne was short lived in many cases.

I have seen Stanadyne PMD's fail in as little as a week.

Had one IP that was installed back in 95 on a "Then New" Burb run exactly one week to the day and then the PMD failed again.

The dealer had a fit but they replaced the IP again.

That truck had 6 Ip's on it in 65K miles.
We offed that rig after the last IP and bought a 454 powered Burb.
It was after that that I joined TDP.

It sucks that the DTECH's are failing though.

Good luck with the new one.


Missy

[JohnC]

the most common failure as reported above is "going all toyota"

Interesting metaphore....

Do they stall afterward? I hope D_tech didn't "solve" the stalling issue by taking a "finger stick" approach to solenoid closure time...

[phantom309]

i have a new standyne grey pmd mounted in the front bumper with an adapter harness,. stock gm on one end and grey stanadyne on the other,.

nick

[Yesterday]

I bought the new gray Stanadyne PMD when they first came out, it quit about
a month ago. Phoned the dealer today about my warranty claim, was told it
has been approved, along with three others. Apparently the first ones out were not very reliable. Was told the new ones are OK... :rolleyes:. We shall see..

Duane

[racer55]

Grey pmd's require gold plated connectors on the extension cable or a new IP harness with gold plated pmd connectors.
There is a couple of vendors on ebay offering an adaptor cable or a new extension cable.
It is possible to alter the older style cables to connect to the new plug design but the dissimilar metals between gold and copper can cause problems.