6.5td stalling and throwing code 35

[gccompton1988]

hi I have a 95 C3500 6.5 td automatic tranny. the problem is it starts then dies and does this for about 15minutes. its also throwing a code 35. i had a bad ip about a year ago so i bought a brand new stanadyne with new pmd as well as the lift pump and oil pressure sensor. I moved the pmd to the top of the engine with a cooler on it. ran fine for about 8 months. then it started dying while i drove started using diesel fuel additive some stp stuff ran fine till now. Gonna change the fuel filter on friday when i can but dont know if that will affect anything considering i change it out about every 4-5 months. i could really use advice cause i really dont know all to much about diesels. thanks

[Yukon6.2]

Hi
And Welcome to the page.
You need to get the PMD out of the engine bay,especialy since you live in the heat.
What kind of PMD?.
Not sure about the code,havn't looked up any for a while,but someone will chime in with the info soon.
If you get a longer harness for the PMD make sure it's a good one.And the bigger the cooler the better.
Thats all i have...for now
Thomas

[gccompton1988]

thanks for this. the pmd is whatever came with the new standayne ip. its the grey one if that makes a difference. i heard about people moving it to the bumper area with an extention on the harness but there seemed to be some debate because of the extended length of the harness. i have been thinking about that though. any suggestions on the location to relocatethe pmd. and i read about people adding 2 stoke oil to there fuel like 200 to 1 ratio any thoughts on that. i have pleanty of that stuff laying around from my bikes. i can try.

[greatwhite]

You're prob not going to want to hear this, but stalling and code 35 ( pulse width error too short) is indicative of a bad pmd.

You can relocate it, but once they start doing this they are only going to get worse.

Unfortunately, replacement is the ony cure.

Ive got a pmd replacement from Bill Heath which comes with a new pmd on a large heat sink and an extension harness that mounts it up front under the bumper.

Its been on there 3 years now with no issues other than having to clean a bit of corrosion shorting on the resistor as a bit of water managed to find it's way into the connector. Not sure if that was the kits fault or mine as i used an old extention harness I had on the truck because the po had hacked it in there. He had cut the pump harness and extended the wiring to mount a pmd on the front acc brackets, so a standard extention harness wouldn't work. I had to remove the lower intake manifold to change the pump harness but I was lazy at first, just used the harness he had hacked up (would have had to remove lower intake to change pump harness) and my laziness probably bit me in the butt. Changed out the pump harness and used the extention harness that came in the kit and my problems went away.

Just an fyi, the PO acc mounted pmd was relocated (by me) to the front bumper nostril after i bought the truck, but it still died the same horrible death. Once theyre damaged, relocating them doesnt help. They will eventually die.

Don't worry about harness length, the one the PO built on the truck was about 5 feet long, some kind of house wiring, a mix of globby solder joints and electrical tape but it worked fine while on there. The new harness i have is 6 feet long. No issues with pulse width or signal tranmissions. The talk about harness length and problems is mostly speculation and largely bunk imho. If there was any truth to it, that cludged together harness that was on there when i bought the truck would have given lots of running problems and it didn't. Just get a good quality extention harness and you're good to go.

Thing is about mounting the pmd on a heat sink hanging off the intake is you can be exposing it to the same (some say worse) heat as on the pump down in the engine valley.

A year in that environment could very well kill the module.

Wish i had better news for ya but there it is.

One thing you can try is pull the connectors apart and inspect for corrosion and filth in there. You many get lucky and that be your problem.

I used to use two stroke (ashless, wc2 code iirc), but dropped it after pulling out my injectors and seeing what to did to them as opposed to good clean straight diesel. I also tried the 30w nd oil thing. Same results. Ash, coking and just a general mess. I would run stanadyne additive if I could get it here, but its not available. I run power service white or silver depending on time of the year. Nowhere near as good as stanadyne stuff, but at least it's engineered to lubricate a pump system and pass through the engine relatively unobtrusively...it's also the best stuff available locally. I'm in a somewhat remote location and you have to take what ya can get sometimes.

If you do run an additive, make sure it specifies "alcohol free" or doesnt list it as an ingredient. Alcohol and stanadyne pumps dont mix well....

Cheers

[Robyn]

I agree

There are a few different PMD based failures.
The stall and code 35
The stalling/restart/ stall and no code
The stall and no restart with no code
The engine goes to full fuel and screams then dies normally with no codes

The first three are anoying, the later can get exciting. :eek:

Try a fresh PMD located to the bumper.

Missy

[gccompton1988]

alright sounds good. im gonna order a new pmd and relocate it in the front. thanks for the advice and ill post my results when i get it done.