View Full Version : Am I eating pmds?
This evening the truck ( 96 k2500 burb) died again, three days after a beand new pmd! What the heck! This really starting to get on my nerves! It does it just like before the replacement pmd. This time, I noticed it only does it when I take my foot off the skinny pedal. It just dies. Once, it let me restart immediately, the second time it would crank and crank with no fire. I disconnected the battery and reconnected and she fired right up. Died a third time down the street. Ran home and got my old pmd (after trying to restart) plugged it in and cranked right up! Is the computer toast? Can the dealer t/s this better? I don't get this at all. Any help or guidance is greatly appreciated.
Neo
Yesterday
09-03-2010, 19:15
Sounds just like what my truck was doing, turns out the IP was toast.
Hope yours isn't the same.
Duane
Were you able to determine it was the ip some way prior to replacing it? Are there tests to make certain that is the problem prior to changing such an expensive part out? Thanks again!
Yukon6.2
09-04-2010, 08:56
Hi
You need to get a good code reader and see what the codes are.I was having trouble with mine and the codes pointed to IP replacement.I got a diagnostic flow chart from alldata,which confirmed the codes,but they also pointed to the optic encoder,i switched that and the truck ran like it did before.I still had some issues which turned out to be a FSD that was not right.In hindsite i think it was flaky right from the begining.
Ther are a few things that could be causing you grief,but untill you get the codes you are just quessing.
Good Luck Thomas
Thanks Thomas,
Any suggestions on the code reader? I am using a AutoXRay SCAN 5000 which I alwasy thought was up there, and seems to be on gassers, but does not find diddly on the 6.5. Shoudl I try the OBD-I hook up? At this point, i have a family trip I have to leave for on Thursday and am starting to think I am going to have to rent something, issue is I need to pull the little pop-up camper. Starting to pull what little hair I have left out. Thank you very much for the info!
Neo
Where and to what is the pmd mounted?
I ask because its not in your sig and you don't mention that info in your problem.
So, after reading a few similar posts and the results, I decided to start back and check the fuel shut off solenoid. I could swear I could feel and hear it "click" / move when the ignition was turned on, but other posts described that if it is opto or the pump itself, there should be some codes (but not the solenoid.) No codes continue to be set, at least when read on the ODB-II buss with the AutoX-ray. I realize it is limited, but if a code is set, it should see it. It just can't see diddly in terms of sensor points or detailed information. But still, no codes are set. Weird thing is the MIL still says it is on (per AutoXRay) but not on dash (yet it does illuminate.) I pulled out the solenoid to verify it is opening. No go. Gave it 12 V straight off the batt (after verifying 12 V coming from the plug to trigger it) and it does not open or anything. Plugged it into the connector and had son toggle the ignition and still no go. Ohmed it out and it is open. No continuity what so ever. I fear there may be multiple things going on, but this certainly is one of them. Any suggestions on where to get one quickly?
Oh, and the PMD is located on an SSDiesel heat sink bolted in the hole in the bumper (pass side) or it was, I moved it to an easier location to service (under the bumper with the sink fins down.) Now, all I have to do it drop it and change it if the situation arises.
Thanks again to all for the continued help.
Neo
stanadyne dealer should be able to get you a fuel shout off solenoid.
Or check with any diesel shops for 1 off a used pump,thats where I got mine when it was found to be open.
In the mean time if you look at the solenoid from underneath you will see a snap ring-remove it and the plunger/pintle and spring comes right out.
Then just put the body back in to stop the flow of fuel out of the pump- the engine will still shut down when the pmd is no longer triggered by the ecm when you shut the key off.(don't plug the wire harness back in the solenloid)I ran mine like that for months with no apparent damage.
Racer55,
Thank you very much for the tip. I hope this is it. I have a trip to the outter banks planned for Thursday, and this truck is an integral part of the trip. I will try that tomorrow. Thank you!! Maybe it will quit dieing.
My hope is that as it got hot, the resistance in the coil elevated and allowed the plunger to drop, shutting it off. Once cool and current could flow better, it would work again. I HOPE! Thanks again for the great tip.
I think I am going to buy the AutoEnginuity package. I hope the OBD-II gives me more info than my AutoXray. Thanks again!
Neo
I recently bought carcode for obd2 and like it pretty well.
I would like it much more if I could find a users manual for it on thier site but have yet to locate that,anyone who has that info please post.
- the engine will still shut down when the pmd is no longer triggered by the ecm when you shut the key off.(don't plug the wire harness back in the solenloid)I ran mine like that for months with no apparent damage.
this is true as long as everything else works correctly. However, if your fuel solenoid sticks or the PMD shorts out the engine will run away and you will have no way to shut it down!
this is true as long as everything else works correctly. However, if your fuel solenoid sticks or the PMD shorts out the engine will run away and you will have no way to shut it down!
Thats excellent information to have,theres no need for a runaway in any situation.
I am a little confused about your reasoning though,the idea of removing the pintle is to test if the solenoid is at fault in the first place.So if the solenoid sticks-can't stick if the pintle's not in there,also I did not intend for the OP to contiuously run the vehicle in that shape.Testing purposes only.(eso solenoid can stick at any time for that matter)
If the pmd shorts out it would most likely burn up or burn out a fuse or fusable link wouldn't it?Thus causing a stall?
I am by no means a diesel expert but in my limited experience a runaway is only caused by combustable fuel being introduced from an unregulated external source or a loss of goverened fuel delivery,please correct me if I am wrong every bit of knowledge gained is worth having.
So I removed the innards and all seemed pretty good. Got another solenoid, will put it in tonight. Simple enough. However, on the way back, after a reasonable (15-20 minute) run at temperature, came to a stop light and had right foot on brake and after 30 to 60 seconds of sitting there idling, she "jumped" like someone had blipped the throttle. Really weird. Scared the pooh out of me. Fortunately I had the foot on the brake hard enough that the truck did not move. I do have the shut-off solenoid out, that is what I picked up. Anyone else have this happen? Other than this, things seem to be back to normal now. Thanks!
Neo
So I removed the innards and all seemed pretty good. Got another solenoid, will put it in tonight. Simple enough. However, on the way back, after a reasonable (15-20 minute) run at temperature, came to a stop light and had right foot on brake and after 30 to 60 seconds of sitting there idling, she "jumped" like someone had blipped the throttle. Really weird. Scared the pooh out of me. Fortunately I had the foot on the brake hard enough that the truck did not move. I do have the shut-off solenoid out, that is what I picked up. Anyone else have this happen? Other than this, things seem to be back to normal now. Thanks!
Neo
There have been some reports of a racing engine condition when using the flight systems/df-tech pmd's recently.
In conclusion did the eso solenoid end up being your major problem?
I definetely feel that the solenoid was the issue. Honestly, I am a bit apprehensive since last week I thought it was the pmd! However, there is no doubt that the solenoid was bad as it homed open, hence would not work for sure. Got a used one from the local stanadyne dealer. I have mounted the old pmd on another heat sink so if I encounter problems, I can just plug it in. Thanks for all the help with this. I have the old solenoid as back ip also.
Is the racing condition a short duration event like the throttle is blipped?
Thanks again!
Neo
Artworks
09-07-2010, 19:18
Check your ecm fuses and the ground at the back of the engine from the glow relay ( as well as all grounds ). I have had a intermitent no start problems with the ground being bad. The wait to start / glow light doesn't come on - the ecm isn't receving a signal to start. If I pull fuses and reinstall it would renew the signal and truck would start. If it was moist and humid weather seamed to do it more offen.
Code reader:
http://www.thedieselpage.com/reviews/quicklynks.htm
Shut off solenoids, PMD's, coolers, etc in stock
Thanks for all the great info.
I will definetely check the grounds. All peripheral systems (glow plugs,etc) all seem to work.
However, I am going to convert to the 4911 db2 mfi when I can. In fact, I called John K. yesterday to buy the turbomaster to eliminate that part of the system prior to doing the mfi conversion. Prolly order it Monday since I am traveling starting tomorrow. Thank you all again!
Neo
last time I'll post on this topic, but thought the latest find could be helpful to someone else.
Drove truck without the fuel shut off valve all the way to the OBX and back, not issues. I had replaced the valve (solenoid) prior to the trip, but that very next morning it dies a minute after starting, so i immediately removed it. Truck did not miss a lick up and back. Pulled like a mule on the beach in really soft sugar-sand. Never stalled or anything. Dropped a friend off on the way home, pulled out on the main drag and it died. would not restart.
Plugged the spare PMD in just to get it off the road, and started right up. Pulled into a good t/s spot and went back to the remote PMD, no go. pulled extension cable to second remote PMD, no go. Plug in the loose (third) PMD and it starts. Suspect the cable. Test cable with DVM and find the "D" lead is open, no conductivity. Pull the cable plug at the PMD apart and lo and behold, it is burnt off. Insulation cooked. Took it apart, cleaned it up and soldered it back and no more issue. I believe there were multiple issues at work here and it just took a little time to slowly eliminate them one by one.
Still going to convert to the DB2, I really don't like the DS4.
Thanks to all for the help.
Neo.
I am a little confused about your reasoning though,the idea of removing the pintle is to test if the solenoid is at fault in the first place.So if the solenoid sticks-can't stick if the pintle's not in there,
There are 2 solenoids, the fuel solenoid and the fuel shutoff solenoid. The former meters the fuel for each injection event. The latter shuts of the fuel coming into the injection pump. If the fuel solenoid sticks, or if the PMD turns it on permanently, the the only way to stop the runaway is to drop the power to the fuel shutoff solenoid.
If the pmd shorts out it would most likely burn up or burn out a fuse or fusable link wouldn't it?
No, it won't necessarily short to ground, it'll just fail to shut the fuel solenoid off and the engine will got to full fuel.
Thus causing a stall?
Actually, the reason PMD issues cause stalling is because the PCM senses that the fuel solenoid is not being properly controlled and stalls the engine prophylactically by dropping the shutoff solenoid (assuming it is all there...)
...a runaway is only caused by combustable fuel being introduced from an unregulated external source or a loss of goverened fuel delivery,please correct me if I am wrong every bit of knowledge gained is worth having.
You are right. A stuck fuel solenoid or a shorted PMD does exactly that.
If the shutoff solenoid weren't necessary, the bean counters would have removed it.
Thankyou for the explanation.
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