PMD going? or injectors?

[ghost183]

need opinions and confirmation here fellas

heres the deal....

when i bought the truck, it had a replacement PMD mounted on a SSD cooler on the intake due to the original failing, its still mounted on the ip for christ sake... truck ran great!! powerful, instant starts.. all was good but i had surging when hot, when ide apply thottle in reverse ( no surging if i let it move on idle in reverse), so, as directed from you informative gents here, i relocated the PMD and cooler to the bumper hole, NO more surging, BUT, i later found out that the pmd isnt waterproof, duh..

rarely, i mean rarely, i would feel a loss of power, intermitant and usually lasted about 3-5 secs, before and after relocation of the pmd...

then i had that major WIF issue (what a nightmare, thanks you guys for all your help) those infamous 251 and 370 codes being repeated a bazillion times.. sheeez

and follow up rattling issue ( another nightmare, and again, thanks are in order for all your help and guidance) remember that one? engine/trans seperation?!?!?!

now... 1/30/09, keep in mind.. NO CODES

i get random stalling.. i coast to the side, and it starts back up within a few secs, only happens when hot and idling for a long time

ive noticed the engine is somewhat tingier, aside from the compression knock, i hear tinging of some kind, so i stethescoped each injector, and found #5 & #8 injectors sound weak, their clicking is faint and not as authoritive as the rest

for the past few days i watched for, and now confirmed a lose of power

also, its start up was usually instant, even in 8 degree weather, -15 with the windchill, instant, but starting up this past week, it kinda hunts and then starts, it sounds as if some cylinders fire right away (like they usuall do) and some are following along for a few secs, alond with a very minimal puff of black smoke, not gray, black

yesterday driving on the NJT, just cruising along, no rush, mainly due to these issues, about 2k rpm, i got a power spike, lasted for about a sec, and it was very noticeable cause the truck had the power it used to have before this power loss issue

and all this with NO SMOKE, i used to get a nice black trail behind me under power on the highway, now.. nothing.. no smoke.. and no power to boot

now.. during all this, these past few daysduring all this testing, its been wet here, rain, snow, lowsy weather.. engine temp is at 170-180 as usual, oil pressure is as before all this

so...

whats going on here? im assuming pmd? or is it those 2 injectors going?

some one point me in the right direction... both my vehicles went down at the same time so im hurting here, sheared my pinion bearing in my other truck and blew the R&P.. so cash is tight.. and i mean tight



anyone local, or somewhat, to brooklyn. ny, who wouldnt mind swapping pmd's with me for a test?



and oh.. just thought ide mention the LP was installed NEW about 7k miles ago

...........

 

[bison]

how is your fuel pressure? new LP dont mean its working, check fuel tank for lots of vac.
I bought a truck 2 years back with same issue and new LP installed, turned out the upstream pump fitting was only hand tight,not leaking fuel, but sucking enough air to cause the problem.

 

[ghost183]

how is your fuel pressure? new LP dont mean its working, check fuel tank for lots of vac.
I bought a truck 2 years back with same issue and new LP installed, turned out the upstream pump fitting was only hand tight,not leaking fuel, but sucking enough air to cause the problem.

no vac from tank, ive learned to pay extra attention when refueling, but where is that connector youre talking about?

i tested the LP using that 1/3 pint test, passed

 

[Turbine Doc]

Sounds like classic FSD once it's been hot a matter of when not if the driver is gonna fail, if it spent any time on a SSD remote under hood, your driver is suspect, do yourself a favor and get the Heath driver unit. Do all gnd checks & also have a look at this diagnostic info http://www.dieseltowingresource.com/showthread.php?t=6872

Since you are in bind, some have added life to theirs, by cleaning up the transistor mounting nuts on back side of the driver under black plastic covers (if you still have them that is), remove nuts brush off the nuts and studs to remove any oxidation then retorque to light snug, if you have a INCH pound torque wrench sung to 10 pound inches torque..NO More as you may snap studs, if you don't have torque wrench snug then 1/4 turn more past snug, CAREFUL if it feels light it is tight it is stop, as easier to retoruqe later than replace driver for broken studs, should not loosen agaiun as under hod you have significant temp changes you don't have on the bumper.

 

[buddy]

No smoke would say no fuel, probably a FSD problem, although more smoke is also a FSD related problem . Why dont you try plugging in the other one on the IP? See if it behaves differently, maybe it really didnt fail yet.

Do you know if the bolts holding the PMD to the heatsink have been tightened regularly with oil changes? If it was having problems before you moved it, it still has the problems I suppose.

Is it grounded where it is in the bumper?

 

[Turbine Doc]

Black smoke out the tail pipe would not be a driver issue, and separate from symptom he is describing, smoke could be injector issue as well as a WG issue, lets work 1 at at time get it running then worry about the smoke, take a run through the member locator sticky, see if somebody near you has posted there, PM them through the site, your other truck a 6.5 ??? if so slave the dirver from it to your truck or vice versa.

 

[ghost183]

after a short drive today, about 11 miles each way, started instantly which it hasnt done in a while, after warming up for about 10 minutes, i drove off, bout 1/2 throttle, dies 50 yards from my house, let it sit for about a minute, started up with 3-5 secs of cranking, NO CODES, went to my destination, and while idling, bout 10 moniutes, dies, let it sit, starts right up, NO CODES, finished my duties, driving home, steady 1200 rpm, local driving, dies, again, let it sit for about a minute, cranked for 3-5 secs, starts and pops a 0251, 0370, 0606, so i make notes, clear codes and start driving, all was well till i got outside my house.. surged once and started shaking, applied throttle and it went away... NO CODES

i decided to take the PMD out of the bumper hole and take a look..

first time i actually took the PMD off the heatsink

resistor pic got in there by accident..

but from what i know.. heat disforms plastics, so judging froim the edges of the PMD cover on the bolt side.. its kinda popping out a little, heat damage? and also, what the h*** happened to those little plastic covers on the PMD? and not to mention the heat transfer gel? the sheet of transfer paste on there now, isnt paste, its discolored metal

and oh, my other truck is a gasser

and the harness is ground up on the IP,

 

[JiFaire]

i decided to take the PMD out of the bumper hole and take a look..

first time i actually took the PMD off the heatsink

but from what i know.. heat disforms plastics, so judging froim the edges of the PMD cover on the bolt side.. its kinda popping out a little, heat damage? and also, what the h*** happened to those little plastic covers on the PMD? and not to mention the heat transfer gel? the sheet of transfer paste on there now, isnt paste, its discolored metal

You done found it, Ghost. The PO didn't seal the thing onto the heat-sink properly, so that FSD is likely baked a bit.

Lots of guys take off the plastic resistor caps - they really serve no purpose if the thing is sealed properly.

Try what Tim suggests and loosen/retorque the transistor nuts. They lose ground because of thermal expansion/cooling and can oxidize. A number of people have resurrected their FSDs for a while by doing that.

When you put it back on the heat-sink, first clean the heat sink really well, use a thin layer of arctic silver (get at any computer store) or a thermal pad, and make sure you use good fasteners so you can ensure that the FSD is adequately clamped to the heat sink... then seal the FSD edges to the heat-sink using RTV.

It might work for a long while, might not, but it's good practice for what you need to do when you replace the FSD with a new one.

 

[ghost183]

You done found it, Ghost. The PO didn't seal the thing onto the heat-sink properly, so that FSD is likely baked a bit.

Lots of guys take off the plastic resistor caps - they really serve no purpose if the thing is sealed properly.

Try what Tim suggests and loosen/retorque the transistor nuts. They lose ground because of thermal expansion/cooling and can oxidize. A number of people have resurrected their FSDs for a while by doing that.

When you put it back on the heat-sink, first clean the heat sink really well, use a thin layer of arctic silver (get at any computer store) or a thermal pad, and make sure you use good fasteners so you can ensure that the FSD is adequately clamped to the heat sink... then seal the FSD edges to the heat-sink using RTV.

It might work for a long while, might not, but it's good practice for what you need to do when you replace the FSD with a new one.

yah.. thats what i thought.. theres actual corrosion on the bolts.. not just surface.. real corrosion, pitting, but anyway, i cleaned them up with a wire wheel, and reinstalled.. ironically, truck started instantly again.. so im keeping my fingers crossed till i get a replacement.. and leave this in the back as a limp home unit

anyone know where i can get replacement bolts? im going to start looking for a replacement PMD, something with a warrantee but in the meantime i think i should also find the bolts..

 

[Missy Good Wench]

The last time I had a PMD issue I bought a DTech PMD and mounted it on the remote.
No issues since.

The PMD can cause all sorts of crap to happen to these things.

MGW

 

[buddy]

You said that there is a remote mounted PMD on there and one still left on the IP. If you get stuck just try plugging your harness back into the PMD on the IP.

You must ground the PMD through the heatink in the bumper, or it will not work, and the one on the IP from the harness doesnt do it, its not a ground wire for the PMD at all. You may be getting it grounded through a bolt that goes into metal, but if you mounted it to a plastic spot I would make sure you get a better ground on it.

And if you havent tightened the bolts holding the PMD down every 3k miles it would also lead to overheating.

 

[ghost183]

You said that there is a remote mounted PMD on there and one still left on the IP. If you get stuck just try plugging your harness back into the PMD on the IP.

You must ground the PMD through the heatink in the bumper, or it will not work, and the one on the IP from the harness doesnt do it, its not a ground wire for the PMD at all. You may be getting it grounded through a bolt that goes into metal, but if you mounted it to a plastic spot I would make sure you get a better ground on it.

And if you havent tightened the bolts holding the PMD down every 3k miles it would also lead to overheating.

oh.. ok, good to know, the IP ground is at the IP and the cooler is screwed into metal, i just wire brushed the bolts that hold the PMD onto the cooler,

as far as the PMD on the IP, yah, i tried that a little while ago.. truck wouldnt start, so im assuming that one is fried

 

[chrisk1500]

You must ground the PMD through the heatink in the bumper, or it will not work,

Huh?

Ever try just plugging a PMD into the harness for a quick second? The PMD functions as long as the harness is grounded to the top of the IP.....

 

[JMJNet]

The pic proof that the PMD on the intake is still get cooked.

Glad you can find it.

I used #6 metal screw last time bought at Lowes or HD. The Stainless Steel kind. Of course, I am using a bare Al heatsink. Your new PMD may come with it.

 

[buddy]

I tried just grounding the harness before and it wouldnt start. I'll try it again, the first time it was one of those in the parking lot of work because I was stranded moments.

 

[JMJNet]

I tried just grounding the harness before and it wouldnt start. I'll try it again, the first time it was one of those in the parking lot of work because I was stranded moments.

PMD ground should not be moved from the IP whatsoever.

Even when it becomes FSD. There was a thread recently about that it messed up when not grounding to IP.

 

[Turbine Doc]

Any fins on that heat sink, looks purty small IMO if a solid block/plate to be an effective heat sink.

Gnd for driver must remain on the IP not only is it the gnd for the driver, it is also the gnd for the fuel solenoid itself, if you peel back the insulation rubber boot on the end of the fuel sol at end of IP you will see those two wires crimp to same wire ring lug that connects to top of the IP optic sensor cover. This is but one of several faults with folks at SSD, when they make incorrect recommendations about the 6.5, this must be connected period, them saying different is wrong, but does a good job of guaranteeing repeat sales of drivers.

 

[ghost183]

Any fins on that heat sink, looks purty small IMO if a solid block/plate to be an effective heat sink..

yah.. its SSD's

i cleaned everything up and the truck seems to be back to normal.. but i didnt get a chance to get it hot yet, driving around the block i dont think will cut it, so ill update again tomorrow when i can stretch it out some on the highway

 

[Tookie]

You must ground the PMD through the heatink in the bumper, or it will not work, and the one on the IP from the harness doesnt do it, its not a ground wire for the PMD at all. You may be getting it grounded through a bolt that goes into metal, but if you mounted it to a plastic spot I would make sure you get a better ground on it.
And if you havent tightened the bolts holding the PMD down every 3k miles it would also lead to overheating.

Every statement in here is incorrect. :nono:
The ground wire that's on the pump already is all you need, and shouldn't
be moved at all. and if you tightened the bolts correctly on the PMD,
while it won't hurt to check them, you certainly don't need to retighten
every 3,000 miles.

 

[Matt Bachand]

FWIW my SSD crapsync only lasted me 4 months mounted on the intake.

While installing the SSD I cut my IP ground and grounded it to the Heatsync as I was told to in the directions.

When installing heaths unit, since I still couldn't get the ground screw outta my IP (why I cut it to begin with). I grounded my PMD
to the bolt on the engine bolt that my D.S. Battery grounds to (This was GMCTD recommendation since it was cut)

Been over 2 years and not a problem since. Am I lucky or is a good ground a good ground....