View Full Version : New Dtech PMD and Still having Issues
I am having shut down and non start issues on hot days even after replacing and relocating the PMD with the d tech PMD 6' extension and #7 resistor. I mounted it in front and just above the radiator. to day it was sunny and 70 degrees and the truck would not start untill dark. the pmd was not even warm to the touch though when it would not start. last week with the new PMD the truck stalled...tried pluging the old PMD which was still mounted to the IP and it would not restart untill is sat for 2 hours. but started on the old PMD. plugged the new Dtech back in a few days ago and it stalled yesterday but started back up but today from sitting in the sun wouldn't start at all.
I'm dumfounded on what is the issue the last stall I check the lift pump and opened the valve at the fuel filter to see if there was pressure and there was. the lift pump was replaced 2 years ago. New batteries 2 months ago. cleaned the 4 ground points in the engine bay and reassembled with dielectric grease. the SES and check engine light are not on when the truck is running so I don't think any codes are being thrown.
also out of curiosity how hot do the PMD get in a 65-70 degree ambient air temp enviroment. When I first got the new PMD I just ran the wire in the cab for a day to see if I had any issues and I grabbed it after driving for 15min. and got a first degree burn should it have been that hot or is that a sign that the new PMD might be bad.
the SES and check engine light are not on when the truck is running so I don't think any codes are being thrown.
This is not a safe assumption. Also, even if there are no codes, a scanner can lend insight into what is causing the stall.
When I first got the new PMD I just ran the wire in the cab for a day to see if I had any issues and I grabbed it after driving for 15min. and got a first degree burn should it have been that hot or is that a sign that the new PMD might be bad.
Was it on a heat sink? If so, sounds like something else is bad, like the fuel solenoid. If not, you may have toasted it...
Look through the stalling thread and related article on the DP. there are many other things to check before condemning the PMD.
"I mounted it in front and just above the radiator."
I'd be curious as to exactly where/how exactly you mounted it and why?
Sounds like it's in a place where hot soak will occur. If you are running free to air you may have already killed it. If it was hot enough to severely burn your hand...
I get a lot of calls from people who mounted the PMD: "To the firewall" "To the intake" "To the inner fender" or "Inside the air box"
Of course I'm the a-hole when I tell them that you can't do that and need a qualified heat sink to dissipate the heat.
I agree 100%
The PMD Must be on a good finned heat sink no matter who made the PMD.
Now my first guess is that the fuel shutoff solenoid could possibly be to blame.
These little devils can and do quit.
Sitting in the sun will not normally effect a PMD.
Be sure the lift pump is working and that you have fuel flowing freely from the filter to the IP
With the help of an assitant, Place the tranny in D and turn the key to start.
The lift pump should run (WRRRRRRRRRRRRR)
Unhook the fuel feed to the IP and be sure that there is a good stream of fuel flowing from the hose when the pump is running.
Just opening the water drain does not indicate if the filter is plugged though.
Just because the pump runs does not mean that its pumping.
Once the engine starts, then open the fuel drain at the front and see iof fuel flows.
If no fuel flows then this means that the pump is not working on the RUN circuit.
Bad Oil pressure switch is a real possibility.
Keep us posted.
Missy
"I mounted it in front and just above the radiator."
I'd be curious as to exactly where/how exactly you mounted it and why?
Sounds like it's in a place where hot soak will occur. If you are running free to air you may have already killed it. If it was hot enough to severely burn your hand...
I mounted it on the front grill so the pmd is flush with the top of the grill opening but not blocking any of the direct air flow to the radiator in a atttempt to get as much fresh cool air flowing over it.
More Power
06-17-2010, 09:53
Use a bottle of water to pour over the PMD when the engine stalls or won't re-start. If cooling it with water allows a re-start, you're on your way to identifying the cause of the heat-related stalling.
I agree with the others, a PMD must be mounted to something that can dissipate the heat.
Jim
I agree 100%
The PMD Must be on a good finned heat sink no matter who made the PMD.
Now my first guess is that the fuel shutoff solenoid could possibly be to blame.
would that be itermitant.seem to be effected by temp and not throw any codes?
Be sure the lift pump is working and that you have fuel flowing freely from the filter to the IP
With the help of an assitant, Place the tranny in D and turn the key to start.
The lift pump should run (WRRRRRRRRRRRRR)
Unhook the fuel feed to the IP and be sure that there is a good stream of fuel flowing from the hose when the pump is running.
I did this except I just opened the drain on top of the fuel filter and fuel shot out. do I need to unhook the fuel feed line?
Bad Oil pressure switch is a real possibility.
I know this doesn't mean it's not bad but I replaced the ops and lp 2 years ago. I also sepcifically asked the tech at Dtech Mike where they recomend mounting the PMD and he said the have a mounting bracket to mount it to the head. I told him I wanted to get it out of the engine bay and he recomended the 6' extension but had no suggestions where to put it.
Keep us posted.
Missy[/QUOTE]
Use a bottle of water to pour over the PMD when the engine stalls or won't re-start. If cooling it with water allows a re-start, you're on your way to identifying the cause of the heat-related stalling.
I agree with the others, a PMD must be mounted to something that can dissipate the heat.
Jim
this last time the truck was just sitting in the sun an 68 degree day for 4-5 hours and it would not start it touched the PMD and it was about the temp of my hand. That's why I'm begining to question whether it the PMD at all. But it seems to correlate with sunny days when it gets above 65 degrees. I line in WA and we have only had 7-8 days like that in the past 3 mo. and every single day I have issues.
Artworks
06-18-2010, 18:03
Check your extension cable ends to make shure that pins are not damaged ( bent) and not making good contact. use some contact cleaner and maybe little scrape with emery. I had a couple of bad extension harness (EDAM) that gave me problems. Also check all grounds.
Maybe you have a ground issue...
Things heat up...expand...make a contact...voila! it starts...
Its a good puzzle you have working there..
phantom309
06-19-2010, 09:16
the glow plugs working right? mebbe when its hot out they aren't cycling?
starts fine when the temps drop?? temp sensor screwed up?
Nick
Burning Oil
06-21-2010, 21:06
What color are the wires in your PMD harness?
Could be fuel delivery problem, grounds, PMD check the easy stuff first like fuel PSI. Do you have a spare PMD to try? If not I recomend getting one as a back up and for these situations.
Good luck.
Leroy
If so, sounds like something else is bad, like the fuel solenoid.
Just to clarify the fuel solenoid not the fuel shut off solenoid. The stinker about this is it never happens when I'm at home and can trouble shoot it with the factory repair manuals and proper tools
Well Dtech thought they sent me a bad PMD and sent me a new one. After a week had the same issue arise again. drove it to work. the truck sat parked for 11 hours went to start it to go home and it just turned over and wouldn't fire. This time though after about 3 min of trying to get it started it fired up but was spewing white smoke and the engine sounded like the timing was way off so I shut it off. and it wouldn't restart. No error codes stored. what the heck it going on???
This may sound overly simplistic, ??? When was the fuel filter last changed ???
Be sure the lift pump works and is actually delivering fuel to the engine.
If your truck has a stick shift it should have a clutch switch. Without pushing the clutch in, turn the key to start. The engine should not spin but the fuel lift pump should work "BUZZZZZZZZZ WHIRRRRRR"
If you have a good generous delivery of fuel to the IP with the pump running, then we will go from there.
With a fresh PMD the game changes some.
White smoke is or can be due to an error in the timing (IP related)
As this came on just after sitting, I am suspect of the injection pump itself.
Another possibility is AIR in the system. Air will drive these things nuts.
You can install a piece of clear plastic hose right before the connection to the IP and then check to see if you are getting air.
You could have a leak prior to the lift pump allowing air to enter.
Air will not cause any fault codes to set.
Internal problems with the IP will normally trip a fault code, even on an OBD1 system.
If you have to you can rig a jug of fuel with an electric fuel pump and feed fuel directly to the inlet atop the IP.
If the truck can be started and run ok, then you will at least know that the issue is in the chassis fuel lines/tank system
Keep us posted.
Missy
Truck started fine with no smoke to day after sitting over night and not doing anything to it
This may sound overly simplistic, ??? When was the fuel filter last changed ??? 3years ago
Be sure the lift pump works and is actually delivering fuel to the engine.
If your truck has a stick shift it should have a clutch switch. Without pushing the clutch in, turn the key to start. The engine should not spin but the fuel lift pump should work "BUZZZZZZZZZ WHIRRRRRR" it works
If you have a good generous delivery of fuel to the IP with the pump running, then we will go from there.
With a fresh PMD the game changes some. On the second new D tech PMD
White smoke is or can be due to an error in the timing (IP related) I'm wondering If I some how got it to acidentally start with out the IP working-b/c now it is fine
As this came on just after sitting, I am suspect of the injection pump itself.
Another possibility is AIR in the system. Air will drive these things nuts.
You can install a piece of clear plastic hose right before the connection to the IP and then check to see if you are getting air.
You could have a leak prior to the lift pump allowing air to enter.
Air will not cause any fault codes to set.
Internal problems with the IP will normally trip a fault code, even on an OBD1 system.
If you have to you can rig a jug of fuel with an electric fuel pump and feed fuel directly to the inlet atop the IP.
If the truck can be started and run ok, then you will at least know that the issue is in the chassis fuel lines/tank system IT will run fine for weeks then stall or a no start. I've cleaned the grounds 2 mo ago
changed filter, lift pump, and OPS about three years ago.
Keep us posted.
Missy
highlighted my responses in red
suburbanK-2500HD
08-05-2010, 23:44
Originally Posted by Robyn http://www.thedieselpageforums.com/tdpforum/images/buttons/viewpost.gif (http://www.thedieselpageforums.com/tdpforum/showthread.php?p=271975#post271975)
This may sound overly simplistic, ??? When was the fuel filter last changed ??? 3years ago
How many miles since the change....
Originally Posted by Robyn http://www.thedieselpageforums.com/tdpforum/images/buttons/viewpost.gif (http://www.thedieselpageforums.com/tdpforum/showthread.php?p=271975#post271975)
This may sound overly simplistic, ??? When was the fuel filter last changed ??? 3years ago
How many miles since the change....
it has been 25,000 mi
More Power
08-06-2010, 09:32
Always change the fuel filter and check the operation of the electric fuel lift pump for ANY engine starting or running problem - before suspecting any other component. The fuel filter should be replaced at least once a year or 10-12K miles.
I've had people say they "changed the fuel filter last month" or that "they can hear the lift pump run for a few seconds when they shut off the engine". All it takes is one bad tank of diesel fuel to plug a filter. You can get bad fuel at any fuel stop. Doesn't happen often, but it does happen - it happened to me one time right after I installed a new fuel filter. As was mentioned earlier, the lift pump can run, but not develop fuel pressure. Valving inside the lift pump can jam due to corrosion or grit, which will prevent the pump from generating pressure.
And... was the new PMD mounted to a finned mounting plate and mounted in a location where it receives plenty of airflow? The driver module MUST be mounted to a finned mounting plate...
Jim
Replaced the fuel filter yesterday rechecked the LP and everything was fine. Today, first sunny day in a week--drove the truck into work it sat in the sun for hours and would problems. after 45 sec it started lots of grey smoke and running ruff. shut it off restarted fine no smoke. Stalled after about a min and would not restart????
I'm wondering if this is something other than the PMD. Prior to replacing the old PMD with the Dtech the truck always started it would stall after dirving for 20min+. about two week after replacing the PMD I started having starting issues when it is warm out now that I think of it the truck has not stalled just not started the PMD is usually fairly cool to the touch even.
So today drove the tuck to work 90+ degree day. wouldn't start at lunch, in the evening the truck started and I let it idle while I went back in the office. All of a sudden I here the engine racing and almost dieing then racing again Etc.. I run out side and the truck is spewing black smoke. I shut it off SES light was on and restart it..it is still smoking and the idle is erratic but SES light is off. shut it off and I came back at 10:00pm it started fine ran great no SES light and drove it the 17mi home. Does this help or just deepen the mystery?
Finally got the GMTD scan to work, Historic codes:
35 Injection pulse width error(Response time too short)
78 wastegate solenoid fault
84 accelerator pedal position circuit fault
99 accelerator pedal position 2 (5 volt reference fault)
OK, not trying to be a wise a$$, but, clear the codes and see what comes back. You don't know how old they are or if they occurred at the same time.
No problems since clearing the codes yet. Would a vacuum pump problem have caused any of my problems? the reason I ask it I started to hear a squeaking a few days ago and found the vacuum pump mounting bolts had worked loose. One even fell out.
93GMCSierra
09-05-2010, 11:55
"I mounted it in front and just above the radiator."
I'd be curious as to exactly where/how exactly you mounted it and why?
Sounds like it's in a place where hot soak will occur. If you are running free to air you may have already killed it. If it was hot enough to severely burn your hand...
I get a lot of calls from people who mounted the PMD: "To the firewall" "To the intake" "To the inner fender" or "Inside the air box"
Of course I'm the a-hole when I tell them that you can't do that and need a qualified heat sink to dissipate the heat.Exactly
Ever try running a computer CPU without a heat sink, you have a $200 paperweight after that, the FSD generates lots of heat as well it may not be quite as bad as a CPU but you could still fry it.
Well,
it finally happened again. the only code was 78- wastegate solenoid fault.
Well, it finally happened again.
Are you still talking about stalling?
DTC 78 won't affect starting or cause stalling.
Racing uncontrolably would lead me to look at the Dtech again.Might be worth a try to switch to a stanadyne pmd?
It is no longer stalling...it won't start when it has been run and sitting in the sun.
So today drove the tuck to work 90+ degree day. wouldn't start at lunch, in the evening the truck started and I let it idle while I went back in the office. All of a sudden I here the engine racing and almost dieing then racing again Etc.. I run out side and the truck is spewing black smoke. I shut it off SES light was on and restart it..it is still smoking and the idle is erratic but SES light is off. shut it off and I came back at 10:00pm it started fine ran great no SES light and drove it the 17mi home. Does this help or just deepen the mystery?
this is what I'm currently dealing with
still have not found the problem. Had not had a issue for several weeks until it got into the 70's last week drove the truck to the gym at lunch and it would not restart until the evening.
Another thing that popped up is it will intermitanly run ruff like it is fuel starved. once it was bad enough to throw code for wastegate solenoid and 35 injector pulse width too short.
Mow how about this My oil pressure gage all of a sudden jumping between 40 and 50psi then all of a sudden it will read a steady 50psi.
I wonder if the ops is failing and creating some or all of this?
Could very well be an OPS/LP problem or wiring connector problem.
The DTC 35 combined with the black smoke and throttle issues points to PMD or fuel solenoid issues. The oil pressure gauge and lift pump are electrically isolated from each other, although a mechanical failure of the sender could affect both. It may be contributing to your problems, but I doubt it is the root cause.
With the wierd electrical things popping up, I am suspecting maybe some grounds have problems.
Check the engine grounds at the RH rear of the intake manifold and be sure they are all good. (two wires from the harness)
Make sure the battery grounds are both good too.
Bad grounds will drive these things nuts and you too :eek:
It's pointless to continue troubleshooting until it is determined just what the PMD is mounted to.
I skimmed through this thread again and did not see where teh OP stated that it was actually mounted to anything.
A failing PMD will act like a cold solder joint. Sometimes worky, others no-worky.
suburbanK-2500HD
11-08-2010, 15:22
Just a little self experience in the PMD dept.
I changed the PMD 2 1/2 years ago, its mounted on a "FSDcooler", and installed at the top of the intake. I have had no problems with mine.
My PMD is from SS diesel.(dont know who make them)
Maybe the temperatures you got over there might shorten the life on theese, just a tough. We have a bit colder temp, spesially in the summertime.
Tried to relocate mine once, but the truck didnt like the extension cable idea. Noticed a change in idle, and performance. (not wery much)
:)
I moved the PMD to the front bumper on a cooler as per suggestion.
Robyn,
I cleaned that ground and several others a few months ago and re mounted with dielectric grease.
In my experience once a PMD exhibits symptoms it is shot. It's not like it is hitting a thermal overload with an auto reset. It is hurt and variations in temperature affect whether it works or not. Running one "free air" is a sure recipe for a failure so keep that in mind.
Also keep in mind that one man's idea of a cooler is not the same as anothers. I see and hear of a lot of sub-standard devices being used because they are cheap or convenient. Most lack proper clamping force and surface finish.
So I talked to Rick at Dtech today,
They suggested.
1)Heat soak on the pump-causing it to lose fuel pressure
2)bad glow plugs system-not cycling correctly-told me to see if I get black smoke while cranking the engine in a no start situation
3)waste gate solenoid-evidently they are electrically tied to the PMD where a short in that system can effect the PMD.
4)bad optical sensor/pump-Told me to disconnect the optical sensor in a no start situation and if it starts in limp mode the pump is probably ok and it is the optical sensor.
5)not enough cranking speed-I replaced the started 1.5 years ago, new batteries 5mo. ago, and cleaned all the ground points 5mo. ago so I really don't think this is the cause.
6) PMD failure-They said they could check the serial number, also I could send it in to have them test it.
He thought it wasn't acting like a typical PMD failure and the fact that I can plug my old PMD in and the truck still behaves the same way.
I'm probably going wait till it happens again and check the optical sensor/ and see if I get any black smoke on cranking the engine. If that checks out I'll probably send the PMD back to get tested.
So Dtech sent me a service bulletin concerning quad control circuit protection of the PMD essentially it appears the turbo charger solenoid (wategate I believe) can cause no start to the PMD by tripping this thermal protection. This is what it states:
"According to GM reference material the quad driver which includes the PMD drive
command is on the same circuit as the EGR vent solenoid, the EGR control solenoid,
the turbocharger vacuum control solenoid and the transmission 1-2 shift solenoid. If any
of these solenoids, shorts or shorts intermittently, it will trip the quad driver and shut down
all three in the same companion circuit. Since a thermal protection of a quad driver is
much the same as a circuit breaker, it will reset and turn on again."
It goes on to explain how to test for this and shorts in the system. But I'm wondering if the wastegate solenoid error code I get when this happens is the cause.
Ok some new problems surfacing... the past 2 weeks the truck has been stumbeling and stalling b/c more frequent the longer the truck has been driven. Threw DTC 13 shut off solenoid fault and 78 and 35 again. This was on thur. today the Battery light(charging system) light came on after one of the trucks stumbles and the tach started going crazy and eventually went to zero. The tach will stay at zero now until I rev the engine up then it will jump to 2800 and the charging light will go off. the RPM gets below 2800 and the charging light comes on and the tach starts jumping all over the place and goes to zero.
Before the most recent tach and charging system started acting up I was wondering if The PCM was goin gbad with the shut off solenoid codes, waste gate, and throttle response time codes. but now I'm wondering if the alternator is was going bad and creating amperage issues tripping thermal protection or creating havoc with the PCM. Now the batteries were replaced 6mo ago. So I don't think it is a problem with a battery.
Any Ideas???
remove and have alt tested...
have batts load tested..
Check and verify solid/clean connections on all batt cable connections including the starter and clean and tighten all grounds.
first things first
I would replace that Wastegate solenoid. Even if you are using a Turbo master the computer may still see the solenoid or wants to see it in the circuit.
Also GROUNDS be sure that the two ground wires on the LH rear of the intake (by firewall) are good.
These trucks usually have a spilt electrical system. OK the Alternator lead hooks to one battery then the crossover cable hooks to the other to make the complete tie in.
The ground cables can go south in the EYE that connects to the intake manifold.
If one cable is bad it can screw things up really bad.
Get that alternator checked as Rameye mentioned and then check all the cables + and - to be really sure that they are good.
If these cables are the factory ones, they can be badly corroded in the core where you can't see it.
If the voltage that the ECM is seeing is goofy, all sorts of wierd crap can happen
One some years of these trucks, the alternator connects to one battery and the starter connects to the other. If the battery that the starter is using is getting charged the rig will spin over fine. Now if the battery that feeds the rest of the electrical system is not getting power then you have issues
Get the rig eunning and check the voltage at the main power input lug in the power distribution panel (under the hood) check the voltage at each battery and the alternator output lug.
you should see right close to 14V with the engine running. Now some rigs will show 13.5 to 13.8 this is fine
If you see a wide spread from one battery to the other, THIS IS A PROBLEM. Find the cause and fix it.
If you have 14 on one battery and 13 or less at the power lug at the panel then you have issues.
The Ip and the PMD are at the very end of long circuits and use very small wires that compound any voltage issues.
Faulty grounds and voltages can cause all sorts of DTC's to trip.
When we start seeing numerous DTC's all of a sudden and ones that really dont go together, its generally an indication of ground or votage issues.
Keep us posted
Missy
well It's good to hear that this could be the cause of all the issues.
One question where is the sensor for the tach? Why would the tach not working and the battery light seem to be related?
DmaxMaverick
11-22-2010, 15:38
well It's good to hear that this could be the cause of all the issues.
One question where is the sensor for the tach? Why would the tach not working and the battery light seem to be related?
The tach is driven by the alternator. This is why it is important to make sure you replace the alternator with one that has the same size pulley, keep your original pulley, or install a new pulley of the correct size. Changing pulley size changes the tach signal. The Batt/charge lamp and tach failure is a pretty good indicator the alternator is failing, or you have a significant wiring/connector issue.
One question where is the sensor for the tach?
In the alternator...
Why would the tach not working and the battery light seem to be related?
Still wondering? ;)
Actually, the problem could be the trans/gauge circuit in the ignition switch, too. Any shifting issues? Ah, 5 speed, you wouldn't know...
t'was the alternator. still not running right threw DC78 &35 again. will replace the wastgate solenoid as robyn suggested next and see what happens.
Grounds. Check all of them. I had a similar issue with a truck and it was a loose ground problem. One located in a difficult to reach spot.
I think this problem can cause the PMD to fail
Since then when I get a customers truck with PMD symptoms I first add a set of ground wires to the intake, body and chassis direct from the battery neg post before trying anything.
Just sent in for my third PMD under warranty.
After all the hype...
I'm still not convinced D-tech is/was the answer...I've been running a Stan PMD on a cooler for 60k no issues.....(I probably just jinxed myself)
We'll see how the new Stan grey PMD bears out.
jonflies
04-09-2011, 16:54
Can you give us an update? Whatever happened with your situation?
I went back to the original PMD around that time I had my High setting on the blower motor stop working. Thought it was the relay. turned out to be a lose pin connector for the ground path in the wiring harness behind the glove box. The wiring diagrams did not show this as the ground path for the ECM BUT I could not find any other path leading from the ECM which is right there behind the glove box. Anyway since I fixed that pin connector I have not had a problem for 5-8 mo. on the original PMD that was stalling and no starting any time it was hot outside.
I really feel like this was my issue because one oddity I had was the truck would not start if the engine was cold but, the sun had heated up the interior.
Which I'm thinking expanded the connector under the dash and made a loss of continuity. When night came and the interior cooled it would start.
The PCM grounds through 2 pins on the pink connector, C1 and D1. Both grounds terminate at the ground point on the rear of the passenger side intake manifold. The pins you refer to should and I emphasize "should" have no bearing on the PCM or FSD.
I was thinking it was effecting the ECM not the PMD or FSD.
Ahh, I knew that wasn't the gound from the manual. However it sure seems to have been th cause of my trouble and it fits the symptom of why it would not start when the engine and pmd were cool to the touch but the sun had heated up the dash and interior causing the pin to loose contact.
What ever the reason is I'm thrilled the problem is gone:D
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