Stumbles while driving

[JCM5]

OK, I think the PMD is going bad, but before I spend the 500 I just wanted to hear some feed back.

Engine runs fine at start up and even a few hours into the run. Occasionally and I mean occasionally it will act like it is being shut off for 5 seconds then starts right back up by itself. It has done this 3 times and three different trips.

PMD is mounted on pump from 2000. No codes are set. Grounds are OK as far as I know. I dont beleive the ignition switch is acting up, played with the switch while driving and can not repeat the same issue.

I have had a PMD go bad and it shuts the truck down were you have to pull over and wait a minute before it will restart, I never had were the truck appears to be shutting off for a few seconds and then resumes as if nothing has happened for the next 100 miles or soo.

Lift pump and filter are new and the Injection Pump was replaced in 2000 (120K). I now have 160K on the truck.

Spend the money or am I looking in the wrong direction.

[Robyn]

It might be the PMD but there can be other issues.

Do you know where the fuel level was when this happens.

There is a safety bypass valve in the tank that will allow fuel to enter if the sock becomes plugged.

This valve will also allow air to enter when the fuel level gets below about 3/8 of a tank on down especially if the fuel gets sloshed around.

The air entering the system will cause bucking, stumbling and even a shutdown if there is enough getting in.

If the stumble is occuring with a near full tank then this is likely not the issue.

The PMD can do all sorts of crap and sometimes its a simple quicky shutdown and then other times it a shutoff and no restart until cold or possibly a no start at all.

Get the PMD on a cooler out in the grill area where its cool.

The New Dtech PMD's are selling for around $279 here in the Portland (oregon) area and they are supposed to be a better bang for the buck.

Let us know

Robyn

[atom_c]

Mine seems to do that stumbling and almost dying trick usually on a low tank shortly after start up. How do you check/ clean the fuel sock?

Thanks
Adam

[JCM5]

The fuel levels were 3/4 full

Im ahead of you on the fuel tank, I replaced the sending unit in the Tank - not for this issue but because the fuel gauge portion was broken - good time to replace it.

I looked for pinched lines etc.

I also replaced the lift pump just in case, it however tested fine.

Question on this new Dtech unit
The Dtech site says it does not need a heat sink, it does not require one for the new design
Dtech also does not sell a heat sink for there unit, just a remote mounting bracket. Im not even sure if you need one and if the Dtech unit woul match to a heat sink from some one like Acuurate diesel.

[CedarGrove]

The dtech will match to any cooler set up for the stanadyne. The dtech is a little thicker so they send you slightly longer screws. Just put one on my truck today. Didn't solve my fishbite problem though. Still head scratching.

Bought mine from pensascola diesel for 179.00. Free shipping. Ordered Sunday and it arrived today.

Lewis

[94burb]

I finally cured my fishbite.

Changed the encoder sensor in the pump using the http://www.mamut.net/royh/newsdet9.htm instructions. No more fishbite at all and it got rid of DTC 17,18,35. However it did just shut off while driving once or twice since (two weeks) with no codes and I am assuming it was the PMD as it is a few years old and was only remote mounted in the last year. Also the shut off while driving happened before the encoder sensor swap a few times as well. Every time it had no codes and started right up. I have changed the PMD to the DTech one today from Pensacola Diesel and am hoping for the best. It feels and sounds a bit better since the swap. Before that I had to change the sensor on the pedal as well so I think its all good.

[94burb]

Spoke too soon. Went on a 400km run today (200km each way). Truck ran smooth as pie except for this. I parked it for a few hours after arriving at my destination and then when I was about to make my return trip I fired it up and drove around for a bit before hitting the highway. Normal stop and go city driving. SES light came on all of a sudden and it went into limp mode. Key off/on set things back to normal like it usually does when this would happen. I didn't have any other issues on the return trip and it ran perfectly as far as I could tell. Scanned it when I got back and came up with 17,18,35,36,54,62. Now the 17,18,35 could be from before as maybe they were not cleared when we changed the encoder sensor but the others are new. I have seen 54 before and thought it was a byproduct of a bad APP sensor plus bad encoder sensor. I am now wondering if the IP is going. It only has 40k on it so I would be pissed if this is the case. Any ideas would be helpful.