I haul exercise equipment for a living and just came back from a haul to Jackson MS. All the way over the truck was fine but on the way back is when trouble started. The truck started acting like it did before the PMD and the lift pump were replaced, it started hiccuping and dieing mainly in lower speeds. I changed the filter, added some good water remover "just in case" and waited overnight to see what would happen. The next day everything was fine and I made it all the way back to San Antonio without a problem adding some treatment with every fill up. However I wasn't quite home yet I still had to cross town, it was then that it started again but worse I had to shift into neutral and crank it more times than I want to remember as soon as I got home it died one last time and I decided to just let it set overnight. This morning when I got up it cranked up without any issues. Does anyone have a suggestion that doesn involve a new IP, PMD, or lift pump or could one of them be bad again. The PMD and the lift pump were replaced only 5,000 miles or so ago so I would assume that they would still be good. When I replaced the PMD I did not put a remote unit on it I just put original parts back in original positions, could the heat from the engine have caused the PMD to go out again that soon? within 5,000 miles?

By the way this problem has occured while the engine was cold and while the engine was hot.

Can anyone help?

I hope that my signature is up to par but if it is not please let me know so that I can correct it.

Did you install a brand new pmd? Did you use a brand new heat transfer pad between the new pmd and the injection pump?

Yes, it was a brand new part with a new transfer pad. If this is the problem (again...) does anybody know about how much $$ we're talking for the relocate kit? Thanks.

Jared: Change out the OPS. It's not too costly and sounds like the many time it has given me problems.

The entire relocation kit from one of our site sponsors is around $500.

Is your lift pump working? If not, inadequate fuel flow thru the IP could possibly be the cause of the premature pmd failure and/or the cause of your stalling.

Don't just throw parts at it. Diagnose.

I replaced the lift pump when this happened the first time (hoping I wouldn't have to replace the pmd- no luck!). What's the best way to make sure it's still working properly?

Open the petkock valve located near the thermostat housing with the engine running.

If the engine dies within 30 seconds or so, your OPS/LP are suspect. If it keeps chuggin along, then we're barkin up the wrong tree.

I have exactly the same problems with my H1. It has a 6.5L TD and I assume everything still applies. By the way what is the OPS, optical sensor?

I have exactly the same problems with my H1. It has a 6.5L TD and I assume everything still applies. By the way what is the OPS, optical sensor?
Oil Pressure Switch

Certainly something cheap to try on yours, Jared.
You have checked for codes, correct?

Best thing but costly is a fuel pressure gauge if your loading it heavily. The fact that you say at low speed should not be low fuel pressure. The T-valve open test should verify OPS working enough for pressure at low speed. Could still cause low voltage to lift pump. Check with meter.

Better test without gauge, have someone open t-valve and look while reving motor and see if fuel continues to flow.


I just got a PMD isolator from heathdiesel.com.

Call Bill and talk to him about it if you have any doubts, but it's a proven system with 7 year warranty.

It was over $500 but what you gonna do?


Check all wiring and connectors first. Could be that you fix it for free.

Check out the diagnostic checklist first. There are links provided in the list for those who have questions about what each test is. As Wade said, diagnose! Prove the parts failure before replacing it.

There are many reasons why stalling happens. Gotta figger out which one it is.

I did THE LP and OPS test. I opened the valve and let it idle and watched the fuel come out. I waited about two minutes and the engine did not die. I also revved the engine while the valve was open and it continued to dump fuel. Now that I have determined that it is not the LP or OPS what else could it be?
Am I just destined to buy another PMD:(

Power or ground connections are the most common problem.

What codes are you getting now?

I get no codes.

You need to do checklist and do an extensive check of grounds, battery connections and cables, and the harness connections.

Can you hook up the old PMD?

I threw the old PMD away as soon as it was replaced because it was totally dead. But I will check all of the connections and get back with you.

Thanks for your help.

Another possiblity is ignition switch failure. (not the key switch). Located under steering column. Somewhere a pic is posted on here.

'sniff, sniff' ... is that a toasted PMD I smell?

Quick. How old is it? How long is Walt's warranty? Somebody else had one on here not very long ago...

I think you are right about the PMD because it sometimes hiccups before it dies, just like it did when it went out the first time. Thanks for the reminder on the warranty. I will have to give the parts house a call tomorrow to see if I have a warranty.

I will have to give the parts house a call tomorrow to see if I have a warranty.

I think it's a tail-light warranty on PMD's, unless it's Heath's.

Jared:

In addition to cleaning and tightening all grounds, and checking out the ignition switch, you might try re-torquing the transistor nuts under the caps on the backside of the pmd. Finger-tight and then a half-turn more, or else someone on here may know the in-lbs value to tighten them to.

I followed all suggestions in the thread today with no luck. Today it was suggested to me that the fuel solenoid located on the IP may be going out, could this be the problem? It was also suggested to me that the two electronic components on the top and the bottom of the IP might be going out in turn causing the PMD to short out, is this a possibility? Otherwise I don't see any other choice but to change out the PMD. By the way you guys were right about the warranty on the PMD. It was a Stanadyne and they only offer a warranty if one of their certified technicians installed it, otherwise you are out of luck if you buy one of their PMD's.:rippedhan

I followed all suggestions in the thread today with no luck. Today it was suggested to me that the fuel solenoid located on the IP may be going out, could this be the problem? It was also suggested to me that the two electronic components on the top and the bottom of the IP might be going out in turn causing the PMD to short out, is this a possibility?

Uh, I don't THINK so, Tim...

Those components cause different symptoms AND they throw codes when they crap out, IIRC.


Otherwise I don't see any other choice but to change out the PMD. By the way you guys were right about the warranty on the PMD. It was a Stanadyne and they only offer a warranty if one of their certified technicians installed it, otherwise you are out of luck if you buy one of their PMD's.:rippedhan
Yeah, that figures. Sucks, eh?

That's why, with all the aftermarket PMDs available, I went Heath. 7 years is a lot of peace-of-mind, and by the time I got around to changing mine, I was in dire need of some of that. Having a 3/4 ton crap out in the middle of Deerfoot trail, losing the Power Steering, and trying NOT to get killed while you get to the shoulder gets real tiring after the first 7 or 8 times...

I replaced the PMD and the problem seems to have stopped. Unfortunatly I have to haul a load tomorrow and could not wait for an ordered remote unit to come in. So I bought another of the Stanadyne PMD:banghead: , I know that it's like throwing money away but I gotta do what I gotta do.:bawl:

Thanks for all of your help:thankyou2

Don't pitch that FSD module, just yet - we'll look at it when you have some time.............