I think I have become a PMD casualty

[96TD]

Well, it started last year, I think. My cruise control started working intermittently. I parked the truck for the Winter, so I didn't do anything about it. I just recently started driving it again, since we have had some rain wash away the salt. Anyways, when I first started driving it again, the cruise was working fine. Then it was working most of the time, then it wasn't working most of the time. It hasn't worked at all the last few times out with the truck. Well a couple of times when pulling on the highway/freeway/interstate/big road, I have experienced "fishbiting". The truck would buck if I had it floored or almost. But, it was usually when I was in 'D' and not 'OD', so I just figured that I was over reving it. Well, yesterday, I had some fishbiting while just cruising through town. Just twice, then coming around a corner, it just shut off. I threw it in neutral, and restarted it. Later on, on my return trip, I pulled around someone and stepped on it, and it had some more fishbiting. Then, it did it again when I again stepped on it. So, now I want to know what is causing it, so I stepped on it hard a few times, and it died. Had a little trouble restarting, and then babied it on the way home. When I shut it off and came back a few minutes later, it restarted no problem. When it died, I had dash lights.
I haven't had any time to look at it. Probably won't for a few days, so now I am stuck driving the gasser.
I'm going to be picking up a parts truck, as soon as I can get me trailer out from behind a snow bank, and get rid of a parts car or two. Why couldn't this have waited until I got the PMD off of the other one???

 

[Gunner0812]

It could be the PMD. Have you checked out the lift pump? My 96 is doing the same thing and my LP has crapped out! Tried to change out the OPS switch but the lower manifold is in the way. looking for 1 1/16" crows foot.

 

[buddy]

Where is the PMD located? And I assume youre not getting any codes, SES lights?

 

[JiFaire]

It wouldn't surprise me if you aren't getting any SES lights, but failing PMDs can evidence themselves in subcritical codes that hang in history and will definitely kick your Cruise out. You've got an OBD2, so you need a scanner to read them...

That's where I'd start, before taking anything apart or buying new stuff.

 

[96TD]

No codes. I have a ScanGauge.
PMD is still mounted in Death Valley.
Lift pump replaced with one for a 93 last year when I bought the truck and put in the HP4.
I've got today off of work, so I hope to find a little time to play with it today.
I drove the gasser to work yesterday, and the took the diesel out for a short maybe 10 mile trip, and it died on me a few times and didn't want to restart once. It did though and I made it home. Boy was I sweating it out in the drive up once a line of cars got behind me. There's no way I was going to be able to push that thing out of line if it died on me there.
Thanks guys.

 

[JiFaire]

Well, it smells like PMD, and it sounds like PMD, but usually when the cruise stops working for extended periods, there are sympathy codes, so that's a little weird, IMHO.

Want some unsolicited advice? If you can manage it, get a Heath PMD Isolator rather than dorking around with used PMDs... yeah, it's more expensive, but I just don't trust used PMDs - once they've been baked, they don't heal themselves, so it's just a matter of time, and as you mentioned, having your PMD crap out in a line-up or worse, while you're merging into traffic is a life-changing experience.

You wouldn't put used brakes on, would you?

I know, lots of guys do it, but if I was into saving money, I'd find other places to do it.

 

[96TD]

Wel, I had some time to work on it, and test a few things. Whatever it is(I'm still guessing PMD), it is real bad now.

I'll be calling Heath in a few minutes and will be ordering their relocator I think. I was going to go the used route, because I was going to get it on a parts truck, and mine was still working, but with mine not working (probably) a used one without a back up isn't a good idea.

Just for the heck of it, I did the check list, well, most of it.
I'm going to remove stuff that doesn't seem to apply just so there is less to sift through.
One other thing that I think is worth mentioning is that I think the PO ran a WVO setup at some point. The coolant line has been cut and patched together with heater hose, there is a 50 gallon tank in the back, and some wiring plugs that are no longer connected. Also there is a filter setup mounted to the frame rail, but not connected to anything. And I know that running WVO isn't good for the PMD when in the stock location, because the fuel is hotter and doesn't cool the PMD like it should.




- Year: 1996
- Truck model and class 3500
- Automatic
- 180,000miles
- Heath HP4 mechanical wastegate
- ‘F’ engine, Turbo
- Ambient outside temp: 40-60F
- What fuel are you using? Pump Diesel
- What fuel additives are you using?Power Service White bottle Winter mix anti-gel
- Where are you located? Masschusetts

General maintenance: inspect and evaluate the condition of each. When were they last changed?
- Air filter Last Fall
- Fuel filter Last Fall
- CDR Valve? ?????
- Batteries – Good charge, matched, clean connections

______________
- Glow Plugs - 60G look new
- Injectors - 8- don't know how old

History: (Describe how the problem first appeared.)
- What were you doing when it happened? City driving
- How was the truck running fine before this problem appeared? Fine
- Has this problem ever happened before? No
- Describe any related factors that might be part of the problem. See above, possibly ran WVO before.
- No DTCs


Diagnostics:


3] PMD / IP Issues
3a] Location of PMD Mounted on pump
3d] PMD Make: ???
3e] PMD Age: IP is dated 11-04 so probably same.

4] Stalling Issues
4a] Do you experience stalling only when hot? Warm, hot and now when barely warmed up
4b] Does it stall under particular circumstances? Mostly after hitting big pedal
4c] Does pouring cool water over the IP seem to help with restarting? Haven't tried. Always restarts
4d] Is stalling momentary (engine recovers)? Used to be now stalls dead
4e] Does SES light come on when engine hiccups? No
4f] Does cruise control quit working when engine hiccups?Cruise stoppped working altogether
4g] Does re-starting seem to reset engine, restoring cruise and power? Did, now it still dies when hitting the pedal
4h] Changes to dash lights or instruments during stalling events? Dash lights normal, SES comes on when it dies



6c] Have you added a performance PCM (reflash) or Chip? Heath HP4

Well, that is about it.

Anyone have any ideas other than PMD?

 

[JMJNet]

Did you test your LP?

 

[M123KT-450]

Yes definately do the Relocation i relocated the second my truck started having Funny issues it worked out great. ... . these guys helpped me figure out what it was gave plenty of good info i then built my own harness is i was low on fundage and truck as been doing ok. . .

Mike

 

[96TD]

Lift pump is putting out. I can't find my pressure gauge right now, but it seems to be putting out some good pressure when I check the t-valve. It's tought to be sure, because it always restarts. It just takes longer every time. I have to clean the garage and find that pressure gauge so that I can tape it to the windshield.

JiFaire: Unsolicited? Nope, that's why I posted here. I welcome advice. Well, I ordered the PMD. I should have it mid next week. Hopefully that was it. If not, then at least I won't have to worry about the PMD again.
After I poked and prodded the thing, it got worse. I cleaned the grounds that I could find, replaced the fuel filter(didn't look too bad), air filter(looked kind of dirty), and the driver's side glow plugs(looked new but had new ones). After that, I couldn't get it more than 50 feet before it died. The only way that I could get it in the driveway was at idle. If I hit the go pedal it died. I had driven it a little bit, and I think the heat in the engine just made it worse. I'll try fartin' around with it again this weekend, but the way that it dies, I figure it is either PMD, or maybe the solenoid on the IP. I may pick one of those up, but I'm only putting one thing on at a time.

Thanks for the advice guys, and if I come up with something else, I'll post up.

Edit: I just remembered where I put the darn pressure gauge. I tucked it away in a nice easy to find spot, just so that it would be....easy to find. Damn, I must be getting old. I'll definately be trying that out.

 

[96TD]

Yahoo!! (and I don't meant Yahoo .com)

My cruise is finally working again. Oh yeah, and the truck is running good too.
I got my PMD isolator from Heath and when I got home from work, rolled up my sleeves, and installed it. 15 minute job. I do have to get back under the front end. I want to move the oil cooler lines a little. They are rubbing the plate, but not the PMD.
Truck started right up. I took it for a short ride, then took it out for a short trip when I went out last night. Just a couple of miles. No problems.
Then I took it to work this morning, and tested the cruise. Everything seems fine, and based on my Scan Gauge, it looks like my mileage may have increased a bit. I wasn't paying attention to it too much. I spent too much time punching the throttle to see if it would skip, stutter or die. It didn't.

 

[96TD]

Well, a month and then some later, and it is still running. Definately PMD, and my mileage hasn't increased. Just thought I'd update.

 

[Gunner0812]

Thats good news.

 

[M123KT-450]

its always nice to help a fellow 6.5er out.
I just put a New PMD into mine a few weeks ago with a #9 Resister truck goes nice tho the cone intake air filter dose help next is the exhaust for me. . .

Mike