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Newbie help: step-by-step PMD replacement

natjwest

Member
Messages
35
Reaction score
7
Location
Portland, Orygun
I've spent a couple hours on the forums here, learning about PMDs and I think that's my problem. I'm not mechanically inclined, but I am good with tools (carpentry mostly) and generally fearless. I've taken the truck into a diesel mechanic (Parkrose Truck and Auto in Portland Oregon) and they couldn't find anything wrong. It stalled out on me on the way home, so I'm giving up on them. So I'm trying to figure out if I should do a PMD replacement myself or just pay to have it done.

I checked the technical library and it helped me find where the PMD and injector pump is and it looks like it's still there, but I can't be sure if it's ever been replaced or if there is a remote PMD. Not sure how to look for that.

I bought the truck in the spring so don't know much of these answers below.

Problem: Truck stalls as if no gas, electrics work, no codes.

Demographics:
- Year: 2000
- Truck model and class: k2500
- Automatic or Standard: Automatic
- Mileage: (indicate miles or km) 188,000mi
- Replaced parts and mods (IP, PMD, chip/PCM, TM, injectors etc): unknown
- Model: ‘S’ or ‘F’ engine, NA or Turbo, EGR?: Turbo, not sure about the others
- Ambient outside temp: 60-80F
- What fuel are you using?: #2 and B99, mostly B99 where available
- What fuel additives are you using?: None
- Where are you located?: Portland Oregon

General maintenance: inspect and evaluate the condition of each. When were they last changed?
- Air filter: inspected recently
- Fuel filter: two weeks, 1000 miles ago
- CDR Valve?: unknown
- Coolant – last flushed/replaced at: unknown
- Oil – synthetic/regular, changed at: regular about 6k miles ago
- Batteries – state of charge, (matched set) replaced at: Spring 2010, good charge
- Battery cables and grounds (removed, cleaned and tightened): Spring 2010
- Glow Plugs - how many miles on them?: unknown What type?: unknown
- Injectors - last changed at: unknown


History: (Describe how the problem first appeared.)
- What were you doing when it happened?: Cruise control about 65mph
- How was the truck running fine before this problem appeared?: Yes
- Has this problem ever happened before?: about 10 times since then. I changed the fuel filter and it stopped for 1000 miles or so.
- Describe any related factors that might be part of the problem: Switch to B99 early summer
- Have you checked for DTC (Diagnostic Trouble Codes)? (Y.N) Yes And? no codes


Diagnostics:

1] Starting:
1a] Does the engine start? Yes
1b] Does the engine crank over? Yes
1c] Are your batteries fully charged? Yes
1d] Have you removed, cleaned, and tightened all battery connections? Yes
1e] Does your Wait to Start light come on for a time? How long? Yes, about five seconds
1f] Does your glow plug light come on? don't think so, can't remember seeing a glow plug light? For how long? _________
1g] Do you see smoke from the exhaust while cranking? What color? briefly, a nice white puff only when cold
1h] Does the Service Engine Light Glow during Start/bulb check? Yes

2] Fuel Issues (if not running): runs fine, section skipped.

3] PMD / IP Issues
3a] Location of PMD (on pump, on intake, remote mounted): appears to be on pump
3b] Condition of Extension harness (if used) Vendor or Homemade? unknown
3c] Condition of grounds / ground wires to IP / PMD. Check Harness. unknown
3d] PMD Make: unknown
3e] PMD Age: unknown

4] Stalling Issues
4a] Do you experience stalling only when hot? so far, yes
4b] Does it stall under particular circumstances? (ie hit bump, or on accel) I think only under acceleration, but it can be mild. Stalled tonight backing up into my driveway
4c] Does pouring cool water over the IP seem to help with restarting? never any problem restarting after about a minute
4d] Is stalling momentary (engine recovers)? no, it dies all the way, then I wait a minute and it starts just fine.
4e] Does SES light come on when engine hiccups? don't think so, no
4f] Does cruise control quit working when engine hiccups? yes
4g] Does re-starting seem to reset engine, restoring cruise and power? yes
4h] Changes to dash lights or instruments during stalling events? check gages and battery icon are lit when engine stalls

5] Running Issues
none, other than stalling

6] Performance Issues
6a] Do you have gauges (boost, EGT) ? no
6b] Maximum boost under load? unknown
6c] Have you added a performance PCM (reflash) or Chip? no
6d] Have you changed exhaust / downpipe / crossover? no
6e] Wastegate – mechanical or vacuum (OEM)? appears OEM

7] Temperature-related Issues:
7a] Single or dual thermostats? single
7b] Have you replaced them lately? Manufacturer of replacements? unknown
7c] Have you pulled and cleaned Radiator and coolers lately? unknown
7d] Have you replaced the fan clutch? Manufacturer of replacement? unknown

List and describe any other factors which are not addressed in this checklist. We can’t see, hear, smell, or touch your truck, so the more descriptive information you can give, the more likely it is that somebody can assist you.
As I mentioned in the beginning, I switched to B99 in early summer when I bought the truck. It ran fine for about 2000 miles with a mix of B99 and #2. Then just last week on a trip to California, it stalled four time on the freeway with no load. I found a mechanic in Grants Pass who helped me replace the fuel filter (I had not done so since switching to B99) and the problem went away. Drove for another approx 1000 miles with no issues then stalled on my three times in one short ride home. Took it to the mechanic who couldn't find anything wrong, but I don't think they knew what they were doing. I have an appointment in two days with Green Drop Garage (Bio and Veggie specialists) for diagnostic.
 
best place to get the relocation kit.. http://www.pmdcable.com/

its pretty straight forward, you just unplug the one on the pump, plug in the extension cable and new pmd mounted behind the license plate...
 
If you had a plugged fuel filter you could have been starving the injection pump and that alone could lead to a pmd failure.
The pmd when mounted in the stock location on the side of the IP relies on fuel in the fuel well of the IP for cooling.

If you had ever had a remote mounted pmd the wiring harness for the pmd would no longer be plugged into the original pmd,the harness would be extended out away from the IP to an aluminum heatsink mounted on the intake manifold or connected to an extension harness that would most likely be routed towards the fron of the truck outside the engine bay.

If the pmd mounted on the pump still has a wiring harness connected you are still using it as the primary and likely the only pmd.A failed pmd mounted in the stock location can be left in place when remote mounting a new pmd.

I reccommend you buy a complete remote pmd kit consiting of: a new pmd,an aluminum heatsink,a new pmd resistor and a 6 foot extension harness.
Note:the new stanadyne grey pmd's require a different harness connector so whatever you buy get a complete kit.

The hardest part about installing a remote pmd kit is removing the stock pmd harness plug from the old pmd,after that routing the extension harness away from moving parts like the fan ect. towards the frt of the truck and mounting the pmd/heatsink combo behind the frt bumper or behind the grill is quite easy.

The resistor if not already mounted in the new pmd needs to be installed correctly with the resistor # facing you and bottomed on the connector pins of the pmd.
 
The hardest part about installing a remote pmd kit is removing the stock pmd harness plug from the old pmd,after that routing the extension harness away from moving parts like the fan ect. towards the frt of the truck and mounting the pmd/heatsink combo behind the frt bumper or behind the grill is quite easy.

It looks like i need to take of the manifold to get access to it. Am I right there? The whole PMD area is really buried. Do you know of any threads on this forum that are step-by-step replacements?
 
I have not done a search for any threads but when I did mine I left the upper intake on.
I used 2 long flat screwdrivers,1 to gently pry the connector tab away and 1 to push the connector back towards the firewall to unhook it.I then used a dental pick type tool to fish the harness up and out to where I could connect the extension harness,some folks just use a coat hanger or a stiff piece of bent wire.

Be gentle when pulling the harness out,sometimes if the IP has been changed lazy mechanics tangle it up under the intake and the harness will barely reach far enough to connect the extension.(like mine was)
Normally it should not be a problem but you never know untill you try.

Some vendors tell you to mount the heatsink/pmd combo to the upper intake so you don't need an extension harness-DON"T do it that way-move it outside the engine bay.
Those same vendors tell you to relocate the fuel solenoid ground to the heatsink as well-again DON"T do it that way.The fuel solenoid ground works best when left in its original place on top of the IP held down by an Optical Sensor screw.
 
Losing cruise is a good indicator the PMD is bad, bio diesel will clean a lot of crud and plug your filter. A new fuel filter wouldn't hurt.
 
Welcome aboard.

If you aren't mechanical, but good with tools, you are going to be mechanical in another year or 2 with a big old Chevy diesel.

It's pretty much dead on for PMD being your issue.

Shouldn't have to remove the intake. You may need long fingers, patience and a long skinny screwdriver for this job.
 
You should revist the fuel issues part of the checklist. Using B99 is not a good idea in general for this fuel system. A few gallons a tank would be fine, but unless you are an experienced bio/veggie type owner I wouldnt use all B99 ever. Significantly changing the opacity of fuel will affect the injection pump too if its different than normal fuel. You should revisit the fueling area because you should check your fuel pressure out the drain, then pull the IP inlet line off and test the fuel pressure there. That would show you if the LP is working, and if the filter is clogged. It could be a combo of both, LP not working and any filter clog would make it more and more difficult for IP to pull fuel from tank. Mechanics know nothing about these engines, not even the veggy specialist, but they will understand the importance of fuel filter and fuel pumps.

Not sure of Bio's impact to the optic lens in the IP, but Stanadyne wont guarantee their IPs if anything over B5 is used.

These are older engines too, unless using additional filtering or synthetic oils I wouldnt run it past 3000 miles, and youre at double that now. The new engines run extended intervals but this is a dinosaur design 30 years old in almost recent trucks.

The PMD is also a good place to be looking though, so I would also pursue that avenue for a reliable truck.
 
...Using B99 is not a good idea in general for this fuel system...
Yeah, I'm figuring that out now. I'm switching to B5 as of today. As an aside, are any newer trucks (2004+) just great for B99?

...Mechanics know nothing about these engines, not even the veggy specialist
Your recommendations sound like something I would need to learn to do. How do I check the fuel pressure out of the drain and at the IP inlet line?
 
If you check his website he sales the PMD also as well as the kit..

GM now uses the Dtech PMD as a replacement for the factory installed PMD. We are going to give a one year warranty on the Dtech PMD when you buy the Extension cable and heat sink combo for $338.99. We will extend the warranty to 7 years. We give you the option, you get the 7 year warranty when you buy the Dtech PMD, extension cable and heat sink combo for $549.00 You get the same exact parts but get to choose your warranty.

Also I doubt that any local parts house will carry it... And as far as the D-tech vs Stanadyne i think its 6-1 but the Stanadyne has a different style of connector..
 
Where do I get the actual PMD? Local shop like Kragen? Which is the better one to get DTech or Stanadyne grey?

You can purchase the PMD from pmdcable.com, a whole kit with PMD, extension cable and heatsink. Or you can get the Dtech PMD at Pensacola Diesel or any parts store (parts store probably charge more). The grey Stanadyne unit will cost you more, because the gold pinned cable runs more and you would have to change out the IP harness which involves removing the lower intake. So I would suggest the Dtech PMD.
 
I bought the pmd of pmdcable.com and it was super easy and good quality. I also have step by step pics of my install if you are interested feel free to pm me
 
Yeah, I'm figuring that out now. I'm switching to B5 as of today. As an aside, are any newer trucks (2004+) just great for B99?


Your recommendations sound like something I would need to learn to do. How do I check the fuel pressure out of the drain and at the IP inlet line?

You need to read this thread about 10 times to let it soak in http://www.thetruckstop.us/forum/sh...t-Pumps-amp-OPS-operation-and-troubleshooting

Need a fuel pressure gauge, like local parts store might have, hopefully cheap, $25 or less. They are usually fuel pump/vacuum gauges for carbeurated engines. That thread has all the information.

The drain valve with hose to drain it is on the thermostat housing, you should be running that out for several seconds with each oil change at least to remove water and crud from the filter housing. Its fuel that comes out, but water in it and sediment, so need to collect it in a bottle or something. The IP has the inlet on driver side, and its secured with a hose clamp, so you just loosen hose clamp and pull fuel line up to put the gauge on the end of it. The thread explains that your Lift Pump (LP) will come on during the WTS/glow plug cycle time, so you can turn ign to on and get pressure readings for about 10 seconds, or at least should, and there is also a diagnostic port by the fuse center that you could jumper 12V to run the lift pump. the drain is prefilter and the IP inlet is obviously post filter. The reason to test in both areas is to determine how clogged the filter or filter housing or fuel lines may be if there is a large difference in pressure between the two, when there should only be about 25% difference in pressure. If there is a 50% difference then change out the filter, and it that doesnt help then you may need to pull the filter housing out and clean it up. ]

B99 can also eat up seals and rubber line I think, so running it too long could cuase old fuel lines under the intake to rot and get cracks faster. Those are always suspect lines when having fueling issues, especially if you can smell fuel.

And not necessarily because of B99 but that it cleans stuff so well it could clog up your fuel tank sock.
 
Wow okay I have some work ahead of me. Thank you very much for taking the time to assist with another newb. I will put in an order for DTech from pmdcable.com tomorrow and skip the veggie mechanic appointment. I have a friend who is pretty handy with auto repair, maybe I can lean on him for a hand.
 
No one has mentioned the possibility of the vent in the fuel cap being plugged. When you open the fuel cap is there a vacume sound? If the vent in the fuel cap or the wrong cap[gasser] is plugged it can starve the fuel pump.Does your fuel cap say"diesel fuel only"?
Oh, Welcome to the best diesel site.
 
No one has mentioned the possibility of the vent in the fuel cap being plugged. When you open the fuel cap is there a vacume sound? If the vent in the fuel cap or the wrong cap[gasser] is plugged it can starve the fuel pump.Does your fuel cap say"diesel fuel only"?
Oh, Welcome to the best diesel site.

good point, another reason never to skip over the fueling issues part of the checklist
 
...When you open the fuel cap is there a vacume sound? ....Does your fuel cap say"diesel fuel only"?
When you say fuel cap, do you literally mean the cap on the fuel tank? Or do you mean the cap on the fuel filter? The fuel filter cap doesn't mention diesel, but I can't see how it would be the wrong one. The fuel tank cap does say "diesel only" and yes I get a vacuum-sucking sound when I remove it.

I went to the veggie mechanic today and he recommended I do the PMD replacement myself, so I put in an order for a DTech PMD from pmdcable.com, will get shipped on Monday. Also bought the fuel pressure and turbo boost bolt/sensors while I was at it. I'll replace the fuel filter at the same time that I do the PMD relocation. And probably another oil change while I'm at it.
 
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