Hi:

New guy here. Once upon a time, I had a Maxima Diesel. Flash forward 18 years; my wife wants something that seats 8, is in good shape, and can be taken on long road trips with the kids. We live in Nebraska, so we also want something with 4WD.

I saw an ad for a 1997 diesel 1500 Subuurban with 150,000 miles. Dealer states one owner (truth - confirmed); pictures showed an immaculate interior with leather and all power options working. Exterior has one silver-dollar sized ding by a headlamo, but otherwise is dent/scratch/rust free and appears to have been garage kept.

I paid $6K. The dealer is in Long Island. I drove the Suburban from NY to 20 miles from Omaha, where it died on I-80.

Any thoughts you have are appreciated. From reading the forums, I see the fuel pumps (lift & injector) as possible culprits, as well as the fuel pump module, and I believe I read about an oil pressure sending unit.

1. Describe the problem you are having in detail: Vehicle was running and quit on the highway. Crank/no start. Dealer initially said that they were able to get it to start, but it needed alternator, fuel filter, and air filter. We dd that, and now it won't start, and the tech is stumped.

2. Year of truck/engine. 1997 Suburban 6.5 Diesel
3. Odometer reading (indicate miles or kilometers). +/- 151, 500
4. Indicate the model number on the Injection pump (starts DS4 or DB2......).
:confused:

5. Indicate if you know if it’s a 1500, 2500, 2500HD, 3500, 3500HD.


6. Do you have an EGR on the enginehttp://images.intellitxt.com/ast/adTypes/2_bing.gif (http://www.dieselplace.com/forum/showthread.php?t=42248#)? (An F or an S engine code 8th VIN digit)

7. Air Filter condition (visual check). Tech stated AF was dirty and I told im to replace
8. Fuel filter condition (freshly changed, mileage since changed). Tech stated FF was new, but was aftermarket, and changeout had been done wrong. Result was new filter, but lots of crud in the filter housing area. Replaced with stock filter.
9. Location of PMD/FSD (http://www.dieselplace.com/forum/showthread.php?t=39436)? (ex. on pump/remote over intake, behind bumper).
:confused:
9a. If remote mounted, describe wiring harness (homemade or purchased from which vendor).
:confused:
9b. Indicate the location and condition of the FSD/IP grounding wire.
:confused:
10. Outside Temperature (C or F). 12° F

11. Service Engine Light while running?- on/off/intermittent
11a. Service Engine light does glow during start/cranking/bulb check: Yes/No
12.Have you scanned for engine codes? Yes/No Tech scanned; I don't know what came up
12a. List exact results on engine codes (http://www.dieselplace.com/forum/dtc.php).
:confused:

13. Condition of Battery terminals (removed, cleaned and tightened).
Tech said upon arrival, ground terminals were loose. He stated at that time, he tightened and was able to crank and start engine.
14. Known condition and age of Batteries.
:confused:
14a. Are batteries a matched set of same age?
They appear to be
15. Condition of Major Grounds (http://www.dieselplace.com/forum/showthread.php?t=157085) (removed, cleaned and tightened)
:confused:

16. Does engine crank, or "turn over"?
At this time, crank, but no start
16a. Does engine start and run?
No
17. If engine does not start- Crack injector line (http://www.dieselplace.com/forum/showthread.php?p=2188140#post2188140): do you have fuel? Yes/No
Last report I got was the tech broke two lines open and got weak flow

18. Does your Wait To Start light come on?

Yes
18a.Number of seconds WTS light is lit.

When it was running, WTS light came on for about 5-7 seconds, went put, and flashed 1-3 times after a cold start
19. Engine Cranking speed (if you have an accurate tachometer).
:confused:

20. Are you experiencing Stalling?
No
20a. Describe the event (upon startup only, down the road, hit a bump, etc...)
I stopped briefly to get a drink and noticed a whine or howl. I'd been driving the vehicle in snow, and it had been running strong; I mistakenly assumed wet belt. About 20 more miles, vehicle died at highway speed. No gauge or warning light indications beforehand. Upon stopping, I attemted restart. Vehicle cranked and sounded like it wanted to start, but would not start. I had it towed to a Chevy dealer. They said they initially tightened the grounds, and got it to crank and start. The tech said alternator output was low, and theorized this as the primary cause. Also stated vehicle needed air and fuel filters. Tech said serp belt was good.
20b. Do you notice loss of dash or instruments?
No
21. Check turbo inlet and air filter for obstructions.
:confused:
22. In a no-hot start, pour a bottle of room-temp water on the injection pump. Does it start now?
:confused:
23. Lift pump test (http://dieselplace.com/forum/showthread.php?t=39350) - Describe results.
I don't know that the lift pump has been tested yet
24. Upon cold start, does the radiator hose get hard quickly? Yes/No
:confused:
25. Upon cold start, do you have excessive white smoke? Yes/No
Keeping in mind the vehicle is new to me, I'd say no
26. Do you have excessive cranking time before the engine starts? Yes/No
When it was starting, no
27. Have you used the block heater? Does it affect engine starting? (only try for starting problems).
N/A
28. Are all glow plugs in proper working order (http://www.dieselplace.com/forum/showthread.php?t=39182)?
Tech says "yes"

29. During hard acceleration, do you have excessive black smoke? Yes/No
30. Do you have any unusual exhaust smoke issues?
No
31. Turbo check out (http://dieselplace.com/forum/showthread.php?t=39368) - Pass/Fail
:confused:, but I will say that vehicle ran strong at highway speeds for over 1,200 miles prior to breakdown
32. Indicate fuel that you are using: Bio-Diesel, #2 Diesel, SVO/WVO, other
32a. If running Veggie Oil fuel setup, indicate details of your conversion (homemade or packaged system). N/A
33. Are you using any fuel additives? If so, please list.N/A
34. Upon unscrewing fuel cap, do you have a large vacuum formed in the tank? Yes/No Define large. There is a vaccum like most any other gas cap
35. Do you have any service history available that might pertain to the problem you are having?
No
36. Please indicate any modifications to the vehicle that might help us diagnose better.
Vehicle has aftermarket exterior lighting and what appear to be the remnants of an aftermarket alarm system.

In addition to AF/FF & Alt, the 4WD Hi Lo switch was intermittent inop, and was replaced. Tech confirmef 4wd does function normally when old swith was bypassed, and I was able to use it on trip from Long Island to Omaha.

Tech stated that vehicle also has leak at the oil cooler lines, needs a gasket at a coolant crossover pipe, and has a leak at an oil filter adapter.

On the headlamp switch, I noted a buzzing when the switch was placed in the middle position. Tech thinks this is related to the alternator.

Tech is frustrated. He is now thinking it may be a FP Module. Service Writer said it might be lift pump, and indicated that is a $1,200 part (heck -- I didn't the LP was that much -- the injector pump, yes, but not the LP; he may have misspoken, or they may be trying to rob me).

Sounds like it could be a pmd. It should be relocated from the stock position. 1200 for a lift pump is robbery.

Sounds like a failed PMD, The lift pump could be tested, by putting 12V to it, and opening the tvalve to check for fuel flow. The PMD failing will just make truck die, some times it will restart, some times not. It throws No codes when it fails. =(
DO NOT let them sell you and Injection pump!! They come with the PMD on it,, and Most of the time it's the PMD that fixes it, and NOT the injection pump, PMD is $300, IP is ALOT more!! The GM tech, all great guys, are Not that versed on the 6.5
Go to the FAQ section of our forum, and read. as you have some down time till the shop reopens, and get some info from us guys, as WE know butt load more then the tech's do! Most of us have been where you are. You got a great burban there, and with some help from us, a few modifcations, you'll be happy with it for a long time!

I second that!

I appreciate the quick and informative responses, and I will be pouring over the FAQ.

Just to make sure I understand: PMD = pump module, correct?

If one relocates the PMD, where should it be placed, and is this something a GM tech will do, or will I need to do this myself/get an indy shop to perform?

If they do make a compelling case that the lift pump is at fault, what should we be talking? My understanding was that the IP is about $1,300, but the lift pump is like $200-400 bucks (+ labor, of course).

I live in Omaha, but my work takes me to Des Moines, Sioux Falls, Lincoln, Grand Island, and Kearney. Not to knock the guy who is working on the vehicle now, but if anyone knows a top notch diesel shop in this part of the world, please send a PM. Once we overcome these current issues, the plan to have this Suburban for at least 150,000 miles.

GM lift pump is only about $100 and way under one hour to install.

If you need a mechanic in that area, let me know. I am originally from Glenwood, and my father is a well known mechanic. He has never worked much on 6.5's but knows plenty of other mechanics who have and would be happy to help you out and for a good price. Just PM me.

BTW, whereabouts in Omaha are you from?

~Will Courtier~

i vote for the pmd...been there, as have many others... i put a heath diesel on mine, more expensive, but i liked the warranty...

Depending on where your located at i can get you a pmd like 150. Also the lift pump can be replaced in like 10 minute by anyone with basic mechanical knowledge

When the vehicle died, was it just like the key had been turned off, or did it stop responding and kept idling down, until it shut down because it couldn't stay running?

Knowing how it died will help us out too with diagnosis.

Because these beasts from 94+ were electronic injection if the alty craps out, or even if the main line from the alty to the batteries comes loose, these things will die once battery power is gone. (This would be noticeable though)

If it's the PMD that's your issue it'll stall out just as if you turned the key off, once the solder connection inside them breaks apart from heat damage. if the damage isn't too bad inside the unit, usually you can restart right away, or after a min or 2 of cooling.
When I worked for a Diesel shop, we'd even tell guys to pour water over the PMD to get it to restart so they could get to the shop.

If it's really bad, the solder just won't reconnect and you'll need a new one.

See if you can find a local 6.5er with a good PMD(also called FSD) and if you can swap to the known good one, if your truck starts, you'll KNOW you need a new one, vs guessing and racking up your parts bill further.

As for where to mount the unit, Heath's kit mounts to the black skid plate under the bumper, and most people take their old one, if it's still good, and save a chunk of change by doin it themselves and stick it behind the bumper, or in one of the bumper nostrils. For that you'd need an extension harness. Kits include everything, but cost a pretty penny.

www.pmdcable.com Shoot this guys a email,,, maybe he could send you a whole setup PMD, cooler, and ext cable for a great price, and have someone put it in for you,,

If the tech needs any help understanding the 6.5 point him here and tell HIM to read the FAq's. LOL

Good luck to ya!

When the vehicle died, was it just like the key had been turned off, or did it stop responding and kept idling down, until it shut down because it couldn't stay running?

No, it just quit. Tach went to 0; steering became tough ad there was no assistance from the pump. At the time, I was doing highway speed (65-70). It was night time and it was cold.

If it's the PMD that's your issue it'll stall out just as if you turned the key off, once the solder connection inside them breaks apart from heat damage. if the damage isn't too bad inside the unit, usually you can restart right away, or after a min or 2 of cooling.

When I worked for a Diesel shop, we'd even tell guys to pour water over the PMD to get it to restart so they could get to the shop.

If it's really bad, the solder just won't reconnect and you'll need a new one.

See if you can find a local 6.5er with a good PMD(also called FSD) and if you can swap to the known good one, if your truck starts, you'll KNOW you need a new one, vs guessing and racking up your parts bill further.

The SW says that the tech wants to see if he has one laying around over the weekend. Hopefully he finds one. Obviously, once we get this running, the first order of business will be to find somebody who knows 6.5s in the area.

When it went down, I tried to restart it, and it sounded like it wanted to go, but wouldn't. As I said before, the tech said he was able to fire it off when it first came in; from what everyone here says, that's not inconsistent with a PMD failure.

As for where to mount the unit, Heath's kit mounts to the black skid plate under the bumper, and most people take their old one, if it's still good, and save a chunk of change by doin it themselves and stick it behind the bumper, or in one of the bumper nostrils. For that you'd need an extension harness. Kits include everything, but cost a pretty penny.

Thanks for the advice. It may cost money, but if PMD failure is going to become a regular, recurring theme, I'll spend the money, get the kit, and get it corrected.

I would try the PMD replacement as well.

As I said before, the tech said he was able to fire it off when it first came in; from what everyone here says, that's not inconsistent with a PMD failure.


A PMD failure comes in a few diff flavors, the little black box has quite a few small solder connections inside, as the PMD goes thru heat cycles, over time, a connection will fail with heat. then when it cools down, sometimes it will com back in contact. and the truck will start. heats up, and stalls. Some times it will fail once and restart and run for a few weeks. Some times it will never restart. Thats what makes it hard for those who don't know this to get the Diag correct. Also this is why someone mentioned that pooring cool water on the PMD, will help it to restart. Maybe after it sits all day sunday, it might fire right up for the tech. maybe not.

Hope he has a spare, to try, then you can get one to get you home. But when you get it home, look into getting a remote mounted unit. and leave the one they sell you on the IP as a spare.

Hey man i live in omaha too and i would come to you and we could hook up my pmd to your truck and see if your truck will start. Ill pm you my number and you can call me if you would like me to do that. Also have a friend that has all the parts you need to fix it and i can get you a pmd for like 100-150.

Hey man i live in omaha too and i would come to you and we could hook up my pmd to your truck and see if your truck will start. Ill pm you my number and you can call me if you would like me to do that. Also have a friend that has all the parts you need to fix it and i can get you a pmd for like 100-150.

Bingo. From a guy who's been on the side of the road too, I thank you for being in a position to help him AND are willing to do so. His wife has got to be giving him 'that look' and you'll help him there as well as you'll save him a ton-o-$ and he'll be that much more self sufficient too.

I love being a good samaritan to those in need.

His wife has got to be giving him 'that look'

I'm very lucky -- so far, I've escaped serious wifely criticism. OTOH, if I'd ended up paying for an IP I didn't need, @ $1, 300 +, I'd hear about it when I'm 80. My wife has a good memory that way -- she can remember pretty much every mistake I've made for 25 years ;-).

and you'll help him there as well as you'll save him a ton-o-$ and he'll be that much more self sufficient too.

I love being a good samaritan to those in need.

I very much appreciate his offer, but actually, everyone here has been exceptionally helpful. The Suburban is at a Chevy dealer right now. You have no idea how valuable it is just to have people here pointing me in the right direction, and giving me the knowledge to either say "yes, this makes sense" or "no, button it up -- I'll call a wrecker and have it towed to someone who knows what they are doing."

Sounds to me like a classic PMD problem. Your not the only to have this problem.. DO NOT GO TO THE STEALERSHIP to buy a PMD.. They want like 20x's more money then they are worth. Go through Heath, Summit, Otterzone (Autozone) or somewhere else. What ever you do DON'T BUY FROM THE DEALERS!!! The screwed me for more then a few things!

The dealership is gunna "love" you if the IP "actually" went bad though.. But in that case take it to a Diesel Mech in town.. Try to stay away from dealr as much as possible..

Sorry about my anti-dealership rant.... Lord I apologize.. http://www.youtube.com/watch?v=SdjAw0IhZS4

Now that there is funny.

My first stop at a Stealership resulted in "your truck is too old for us to work on." That cost me $45.

I'm new to Chev diesels, so the first question I have....are you sure the fuel gauge is accurate?

X2 on fuel guage also add some anti jell additive and top off tank with some #1 diesel. Make sure the fuel filter heater is working! You have been in some real cold driving conditions latelyand the above could be a factor. Good posts here as usual:)

Fuel gauge on my truck I guess would qualify as messed up "I think" Because half a tank of diesel fuel in muy truck is 18 gallons of a 32 gallon tank.. But if you top it off and know how many miles you average per tank their is no need for a gauge. It may sound stupid but it makes sense?

I have actually seen some on replace a 6.5 b/c they thought the thing blew up put a new motor in a nothing happened fuel guage even said empty put fuel in it started nice waste of money. needless to say he wasnt in charge any more.

big time double check on the fuel gauge- gm level sensors never have issues. . . (sarcasm)