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Did you make sure a Resistor was installed on the black PMD?
Did you eliminate the extension harness and plug in the PMD on the original IP harness
to rule out the extension being bad?
 

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Discussion Starter #22
Yep there is a resistor in the new one. Double checked it this morning, was hoping it was going to be something easy like it fell out when I was fitting it in the bumper but sadly it was still there. Ohmed it out and its correct for a #9. I even bent the little contacts on it to be sure it was making contact on the pins. At first it didn't seem that snug but after I bent em it felt tight.

Yes tried the new PMD direct and with the harness, no difference. When I plug the original back in no code so it seems to be somehow related to the new one rather than something else in the truck that just happened to fail at the same time. Will have to get to my other truck and swap some things around to see if I can move the issue. If it is the PMD guess I will see how that warranty works, luckily I get along pretty good with most of the guys at my local napa where it seems like I am spending way too much time and money lately.
 

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Yep there is a resistor in the new one. Double checked it this morning, was hoping it was going to be something easy like it fell out when I was fitting it in the bumper but sadly it was still there. Ohmed it out and its correct for a #9. I even bent the little contacts on it to be sure it was making contact on the pins. At first it didn't seem that snug but after I bent em it felt tight.

Yes tried the new PMD direct and with the harness, no difference. When I plug the original back in no code so it seems to be somehow related to the new one rather than something else in the truck that just happened to fail at the same time. Will have to get to my other truck and swap some things around to see if I can move the issue. If it is the PMD guess I will see how that warranty works, luckily I get along pretty good with most of the guys at my local napa where it seems like I am spending way too much time and money lately.

Unfortunately, being new out of the box isn't always so...
Could be a manufacture defect...
 

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Discussion Starter #24
That is what I was thinking. Will know more when I get to my other truck.
 

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Discussion Starter #25
I could not get both trucks together but did get my spare yesterday. Stuck my spare black stanadyne one on today sitting on the bumper (on a heat sync) and re connected batteries. Started right up and no light so figured great, bad dorman part. Mounted the spare in the bumper and got the new one packaged up and figured I would head for Napa. Started it back up and code 35 is back so I am puzzled again. Same as before does not matter if its on the extension or direct. Plugging in the original code goes away.

I don't get what is going on here. What really puzzles me is if I go back to the original code goes away. I would think if I had an air problem or other electrical issue (which is certainly possible on my rust bucket) that it would pop up with the original PMD too? I have driven it a few times and it seems to be running fine, no hiccups just the light.
 

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The grey PMD is stanadyne.

The Black PMD would be D-Tech or Flight Systems PMD
 

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Discussion Starter #27
The grey PMD is stanadyne.

The Black PMD would be D-Tech or Flight Systems PMD
Even the ones that say Stanadyne on em? I thought till 2005ish Stanadyne made their own and they were black? I noticed its flat like the gray ones vs having the bump up like the Dorman one.
 

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Stanadyne PMD used to be black. There is no recess on them.
The latest black Stanadyne no 34583 which is actually a good one compare to anything available now.

There were 3 different version of black Stanadyne PMD before FS/DTech came out.

In addition, as we discussed here, there is now Dorman Made In China PMD in addition to the Black Stanadyne, Grey Stanadyne and Black FS/DTech PMDs.
 

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I recently thought my extension harness was bad, but it was actually the injection pump PMD harness. The one that plugs into the wiring in the intake valley and has 2 wires that go to the Fuel Solenoid on the IP.

I could wiggle the plug at the PMD and it would get all sorts of angry, sputtering, and stalling. You could plug a pallet of PMD's in if this were the case, and have a different issue every time depending on how well it connected on that try.
 

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Whats happening is the Dorman is weaker than the Stanadyne therefore kicking out the DTC..

The PMD, like the PCM employees quad drivers to operate (switch and report) the Fuel Solenoid. Because the FS transistors generate some heat and is high voltage, GM added another set of quad drivers directly into the PMD specifically to further isolate the transistors while still protecting the PCM sensative microprocessors, converters, and voltage regulators from power spikes or sudden surges or brown/black outs...
PMD is a mere extension of the PCM..

Seriously.. the reason why those others are spitting DTCs and not the Stanadyne requires far more explaining than I am willing to commit to at this time..
Do yourself a favor and go over the fuel system with a fine tooth comb..
Better yet, use a hand op vac pump w/ gage.
Disconnect the Fuel Sender "suction" line and cap it off (seal it). Then disconnect the fuel supply hose from the IP. Insert vac pump into IP's disconnected fuel supply hose and apply 15-20" of vacuum while observing the gage. The gage should hold vacuum indefinitely. If not, you got a leak somewhere.
If leak(s) is detected, you could then carefully install a small tire valve stem in the IP disconnected supply hose and pressurize (no more than 20psi) the supply line to force fuel and/or air to leak out of the potential leaks to help track 'em down..
 

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Thats why the latest Stanadyne PMD has a matching gold laden IP harness.. The not so visiable PMD upgrades include much improved internal circuitry aka quad drivers.

Ive been reading about EMI's and the effects of "ringing" in some inferior harness's. All the electronic s'it is :Insane: :Insane: but necessary to understand if we are ever going to resolve the mystery of the infamous PMD Goblin..

The fretting corrosion has been a known problem for some time however it was GMs decission NOT to make the running production change in '98 to fix it in fears it would torpedo there case against Stanadyne who SUED GMCorp for tens if not hundreds of thousands of supposidely "defective" IPs (plus lost wages) that later proved to be perfectly good. Nearly ALL the "defective" IPs being replaced under factory warranty were simply misdiagnosed by inexperience untrained UNQUALIFIED factory authorized ASE service techs, and Stanadyne simply could no longer keep up with all the returns and several of GM production lines at the same time..

I personally recall a time in '97 that my stealership couldnt get a replacement IP (warranty) for several weeks (Stanadyne was NO longer supplying GM with warranteed remans) so GMCorp began to allow there incompetent but factory authorized service centers to subcontract the repair/reman/rebuild to local injection specialist in order to reinstalling them ASAP because for alot of 6.5 owners, our patience was wearing thin.
Suddenly those "outside" invoices began piling up and many went unpaid leaving the dealership to pay the IP shop and then fight with GMCorp to get reimbursed...
Most cases, the techs again failed to follow exact procedures GM service bulletins LITERALLY SPELLED OUT FOR THEM and many shops got burned for not strictly adhering to it.
Thats another reason why many techs who got there arses kicked and/or reemed out started avoiding EFI 6.5TD at all cost.. Once bitten...

I cant locate the Technical Service Bulletin instructing GMCorps authorized service centers "DO NOT SEND DEFECTS TO STANADYNE" yada yada yada that included a lengthy troubleshooting guide and report...


Fact is, it wasnt until GMs bankruptcy deal in 2008 that Stanadyne was no longer legally obligated to remain silent hence the new and much improved PMD and matching IP wiring harness was released soon afterwards.
Apr '09 Stanadyne Parts Bulletin- Subject: New PMD and Wiring Harness for DS Pump Models


bookmark
Service Bulletin- Subject: DS Tranfer Pump Regulator Changes w/ part #s

Service Bulletin- Subject: Engine Surge/ High Fuel Delivery/ Rotor Wear- GM
6.5L Applications With The Model DS PUMP





I recently thought my extension harness was bad, but it was actually the injection pump PMD harness. The one that plugs into the wiring in the intake valley and has 2 wires that go to the Fuel Solenoid on the IP.

I could wiggle the plug at the PMD and it would get all sorts of angry, sputtering, and stalling. You could plug a pallet of PMD's in if this were the case, and have a different issue every time depending on how well it connected on that try.
 

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Discussion Starter #32
So Heavy are you saying that I have a leak and with genuine Stanadyne PMD's its not a problem but with the looser tolerances of the Dorman it trips the code?

Interesting twist is that I had to move on to other things this morning so took another car. Got home tonight and had to shuffle things in the driveway. I'm pretty sure the light was on when I started it and moved it. I shut it off but then decided I needed to haul something so loaded up and hit the road. I can't say for sure if the light was on or off when I started it but part way down the block I noticed it was not on. The PMD that is currently running is the black Stanadyne one. Ran fine and light stayed off for the whole run which included a coupe restarts and about 45 miles.

From reading about the code 35 I got the impression it would never turn itself off. Did I apparently read that wrong? Or did my light burn out, I forgot to look for it when I started up again.
 

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Discussion Starter #33
Ran to the parts store this morning and it was fine and no light. Had to park in the street when I got home. Just started it up to move back into the driveway and light came back. Nothing has changed since last nights trips when the light turned itself off, still running the black stanadyne one.
 

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Are you getting 35 with the Black Stanadyne?
 

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So Heavy are you saying that I have a leak and with genuine Stanadyne PMD's its not a problem but with the looser tolerances of the Dorman it trips the code?

Yes, that is what I am saying.. poorly it seems.





Interesting twist is that I had to move on to other things this morning so took another car. Got home tonight and had to shuffle things in the driveway. I'm pretty sure the light was on when I started it and moved it. I shut it off but then decided I needed to haul something so loaded up and hit the road. I can't say for sure if the light was on or off when I started it but part way down the block I noticed it was not on. The PMD that is currently running is the black Stanadyne one. Ran fine and light stayed off for the whole run which included a coupe restarts and about 45 miles.

From reading about the code 35 I got the impression it would never turn itself off. Did I apparently read that wrong? Or did my light burn out, I forgot to look for it when I started up again.
:popcorn:
 

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Discussion Starter #37
Yes I am now intermittently getting the 35 with the black Stanadyne PMD. Steady 35 with the Dorman one. No code with the grey one but have not tried it for extended periods. Have not had the glitches since I quit running that one.

I have been out of town but the wife had to drive it a couple of times and she said the light has mostly been off but has come on a couple times. I have not had time to check it since I got back to see if its still just 35 or if something new has come up.

I figure the next thing will be to do some swapping with the other truck and see if I get any codes on the other truck. Also going to do some more exploring of the fuel system in general. The other trucks remote PMD is a grey one so I have a variety to play with.

So what may be happening with the tolerances is that maybe the original transistors had somewhat of a lag time in turning on and off so that was designed into the software and timing. Maybe the new dorman ones turn on faster so the result is too much fuel so the computer has to cut back so even though it can adjust for it and still run its tripping the code because its not what its used to ? And my black one is just on the edge so sometimes its alright and other times not?
 

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Discussion Starter #39
The ones I can see are 9's. I don't know what is on the 'original' grey one. I was thinking of picking up a 5 just for fun and seen if maybe that would help keep the light off.
 

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I was hoping you would say 5's. If I understand resistors correctly :confuzeld, the 9's should extend the closure time by providing slightly more fuel and the 5's should have a shorter closure time.

So a 5 might make it worse.

Do you have GMTDScan Basic/Tech? If so, check the "injection pulse width" aka closure time. Should be between 1.5ms and 1.9ms.

More info here: http://www.dieselplace.com/forum/63-gm-diesel-engines/21-6-5l-diesel-engine/655570-ds4-injection-pump-closure-time-follow-up.html#post6456546
 
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