Anyone get a new FSD/PMD and have it fail within a couple of weeks?

The FSD is mounted to a FSDCooler on the inner fender using a new heat transfer pad.

I would contact EDAM (or whatever his name is) and see if he'll send you another one. I suppose it's possible you got a bad one. Mine has been 100% (knock on wood) since I replaced it.

Dave

Never had any new ones go bad that soon. Stanadyne warranties them for 12 months when mounted correctly. Mounting on the fender well is not a good location. There is very little air circulation there to remove the heat from the cooling fins. It could very well get way to hot there.

Could be something else. Do you have the other one for comparison or is it toast?

Any codes? What's it doing? Did you buy a kit or mount the FSD yourself?

Never seen a new one go bad before ... but it's not beyond the realm of possibility. People make 'em, people screw 'em up every so often.

That's why we get warranty, right? Get a new one from the dealer.

I've had a Brand New one go bad pulling it out of the garage with maybe 15 minutes run time on it, remote mounted to a FSD cooler out of the engine bay.

DavePhillips

I realize it may something else, but it's strange that it seems to acts similar to the way the old one did as it was failing, this why I'm askin you guys!

The old one sort of works also smells like the electronics are cooked.

No MIL, but guess it may have stored a code and not displayed the MIL (?).

I mounted the new eBay FSD on to a FSDCooler using a new heat transfer pad. Then moved the "cooler" off the intake to the drivers wheel well until it warms up, then move it totally out of the engine bay.

Possibly if it shut down and then was OK when you started it back up there may be a code.

It didn't start right away I did have to wait about 10 minutes.
Thing is it's cold here like 3 F.

I touched the "cooler" and the FSD it was not even warm.

The only reason I'm panicked, there's still warranty on the unit, but I have ship it and wait (should bought two!?!)

Mine was dying recently. I have a new remote FSD and also I have the original PMD that I believe is still good.

I switched PMD's and problem remained. Sometimes it would take 5 or 6 seconds of cranking to start and would light the light. Others it would start right up and not light the light.

If it coded as it shut down and started normally when it did finally start you would not see it.

Oh, I doubt that you cooked it ... not usually a wintertime thing. Your old one should work OK in the meantime, I would think. Call the vendor ... maybe he'll ship you a new one while you wait to ship the old one back? You might have to give him a credit card number to hold until the return gets there.

Anything I've ever had issues with, the vendors I use have been happy to do that.

BTW - the PMD doesn't have a DTC 'code' of its' own, so don't expect to find one, but what you might see is other IP-related codes... that was the reason GM changed out so many good injection pumps before somebody figured out the FSDs were getting cooked.

There is a doagnostic procedure for testing FSDs, but I can't remember what it is. Ask gmctd.

What's the 4-digit code on the transistors?

There is a doagnostic procedure for testing FSDs,

I think it was about a month ago. I suggested the thread should have been made a "sticky", but I do not think it made it. :(


With so many problems PMD related problems and someone shows how to test them, it should be front page material!!! :)

That procedure was a simple short-test intended to protect the exorbitantly-expensive Bacharach\equiv flow bench from damaged FSD modules.

The only practical test is substitution.

So - what was the 4-digit code on the transistors?

I need to take the FSD off, then I'll post the codes.

As an aside the old one has BM0439.

That one is from 2004, 39th week of - or, 043rd day of '99, julian

I can't believe I'm getting excited about seeing the check engine light!

Well it stalled again, but this restart (within minutes of stalling), had the MIL on.

Won't be able to read codes until monday though!

Got the code it's P0251 !

I have had this code once before and only this DTC. This is with both the old and new FSD.
As you can see I don't get the code all the time.

I"M very confused only have about a week to return the new FSD for "warranty".

Returned the new FSD, vendor sent a replacement all was good for 1.5 weeks.
the today it stalled but restarted right away. No MIL, just shut off?????

Any thoughts.

Still have optical sensor filter harness installed? Mine threw a 251 'cause of that little booger.....

I'll have a look.

Could it cause stalling?

How is the IP wiring attached to the pump?

Is there a photo of the optical sensor filter harness on this site?

I saw some wiring around the IP that had a plastic beigey rectangle block with about 5 wires going into it.

Should be 6 wires, twisted into three pairs -

Looks like this.

The pic above is from SS Diesel's site. I'm not positive that is the harness being talked about.

I also found this from doing a search.

http://www.dieselplace.com/forum/attachment.php?attachmentid=29279&d=1164349095

That's the one(s) - looks like they lost the twist, tho.

Thanks Dave12 that looks very similar to what's under the hood.

If a guy is real patient could the harness be removed without disassembly of the intake?

If I remember correctly from other posts this optical sensor filter harness can be removed and discarded, right?



By the way, Thanks for all the help every has providing!

I think you can unplug it but if not, all you need to remove would be the upper intake (5min job)

Thanks Nick

Is there a gasket to replace or is permatex gasket good enough?

Looks like it would be best to remove it, hands too big and wires don't pull all the way out.

There is a gasket but it's usually re-usable. I've had mine on and off several times with the same gasket.

Dave

The Optical sensor harness was removed, waiting to see if stalling is still an issue.

Today while driving at operating temperature, engine stalled, restarted right away!

Any thoughts

Mine used to go thru a spell like that. It was usually an OPS change out and I was good to go.

Thanks

Is the OPS still an issue with the 96 and up vehicles?

Did you get an extension harness for the FSD? I can't remember. Some guys have problems with the harness. Have you tried plugging the FSD back into the factory harness (eliminating the extension) to see if that fixes the problem?

It's worth a shot.

Dave

What's the date code on the "new" module?

Date code? The serial number with the code in it?
Or the code on the transistors?


Dave12
The extension harness is from eBay, the stalling is very intermittent, so no I have not tried moving it back. I did ring out (ohm meter check) the cable before installing it.

I could move it back the FSD and cooler are still in the engine bay over the drivers fender (until it warms up then moving it right out).

Transistors show earliest date of manufacture.

F'rinstance, if the label shows 2006, but the transistors show 1998, somebody's doin' some underhanded prestidigitation type magic, eh?

Dave12
The extension harness is from eBay, the stalling is very intermittent, so no I have not tried moving it back. I did ring out (ohm meter check) the cable before installing it.

I could move it back the FSD and cooler are still in the engine bay over the drivers fender (until it warms up then moving it right out).

It was just a thought. There was a couple of threads recently with guys having similar problems and it turned out to be the harness. I think you and I bought ours from the same seller. I haven't had one stall (knock on wood) since installing it back in Oct. last year.

Dave

Thanks Dave12 , I believe we got our parts from the same places.

The FSD has the following serial number 345830776267.

On Wednesday the vehicle stalled 4 times!

The engine was at operating temp for at least 15 minutes and not cold outside ~-5C, first time it stalled it restarted right away.

That evening (-15C) it stalled 3 times within 15 minutes.

The first of the 3 stalls had to wait a couple of minutes before the lift pump started ticking.

Each stall after had to wait longer, up to 10 minutes (last stall), before the lift pump said we're go to go. I even used a hammer and banged the frame rail, with key on, nothing, just had to wait until it was ready (??).

Every AM start the lift pump chatters away normally wait waiting for the WTS lamp.

After the 10 minute wait and restart I could hear the LP clacking away all the way home, I had shut the radio and heater fan off!

Once again any input. The truck is not very reliable, now, I'm always looking for a spot to ditch should it decide to take a break!

Side note When I pulled the Optical harness, I removed the intake (top only) and put it back on with out any gasket material, didn't look like there was any there any way.

One more item. No MIL.

Has anyone ever had a PCM go bad?
It's so weird that the engine stalls wait up to 10 minutes (in the intersection) until it's ready to go again.

Is your Ignition switch the original? I have not seen anything mentioned about the ignition switch yet. When it stalls and you attempt to restart it are there any dash lights on?? IE: water in fuel, check gauges, wait to start, seat belt, etc, etc. If the dash lights are not on I would be looking at the Ignition switch real close.

I believe the ignition switch is original.
Anyway to verify the switch, or troubleshoot it?

Earlier posting looking for serial numbers on FSD:
Transistor numbers are:
MJ15004G
BM0634
MEX

FSD Serial 34583 0776267

Ignition switches are expensive, the stealer wants $305.25 in Canadian dollars.

Anyone else changed one to correct intermittent stalling?

Stalled again twice, dash lights that were on: battery, check gauges and MIL. H2O in fuel would flash when cycled.
Still ignition switch.
Wait 10 minutes cylce key lift pump would start up and so would the truck.

Any thoughts?

In that 10 min wait does the lift pump not run? Not that I have any answers but I'm just curious if the lift pump is basically dead for 10 mins and then starts to work again?

Dave

Sure sounds like you have a clogged sock in the tank....that is if the LP doesn't pump fuel but still 'runs'...

That's exactly what's happening. Weird eh.

So the fuel pump 'runs' but no fuel comes out?

Read this and see if it helps...

http://www.dieselplace.com/forum/showthread.php?t=56208

When it stalls, the lift does not operate.
After a time about 10 minutes, the lift pump will run and if cold enough WTS lights.
When the lift pump runs it's enough to prime, but if I hear the lift pump (prime cycle) after waiting and cycling the key, it's ready to start.

It may run for 15 minutes it may run longer.

Try hotwiring the LP and driving it like that for a short time (more than 15 min) and see if you can reproduce the stalling...if not, LP circuit is suspect....if it does still stall the problem may very well be in the sock in the tank...

Could it be your lift pump relay? I read somewhere that if your lift pump has failed, it can sometimes cause the relay to crap out. I might have read that on either the SS Diesel site or Kennedy's site.

Dave

All good idea's.

Chris1500 how are the IP wires secured under that black boot?

What do you mean?

If you are talking about IP wires on fuel solenoid - they are bolted on underneath the big black boot located between the IP outlets.....

Yrs those are connections I mean.
Any way those could come loose?

anything is possible.....

Roughly what size are the studs?


Are nuts with lock washers or nylon insert nuts used to hold the wires in?

Sorry....can't remember off the top of my head...they are very small...that is all I can remember...

They have been known to loosen and cause same symptoms as failing FSD - particularly when folks have been tugging at the FSD harness, trying to get more length out from under the intake manifold, to attach a heat sync (sic).

Also, early versions were crimp-only connectors - later versions are upgraded to crimp\solder connections with teflon-insulated, silver-plated wire.

Dealers and most vendors carry them at about 35bucks - well worth it, and necessary if your harness is pre-'98

The stalling seemed more frequent since I removed the optical sensor filter.

I guess to check the wires on the back of the IP the intake has to come off?

I have a 95 Chev 6.5L TD. My truck stalling like someone reached up and turned off the ignition while going down the road. It would restart after a few seconds but would happen again. My fuel pump was ruled out. I replaced the PMD with a heat sync kit from SS Diesel Supply. No more stalling problems. However, about six months after installation, stalling started again. Contacted SS Diesel Supply thinking I got a bad PMD. As instructed, I removed the heat sync/PMD and used an allen wrench to tighten the screws (4) holding the PMD to the heat sync. Since doing that, no more stalling problems. I am going to check the screws and make sure tight every 3000 miles. Periodic tightening of the screws was on the instructions sheet but I did not do it -- lesson learned. It is my understanding that if the PMD is not really tight against the heat sync unit, heat will build up and cause malfunction. My PMD/heat sync unit is mounted to the manifold. Hope this helps.

Bradley if retorquing is required every 3K miles, then you don't have a solution you have another unnecessary maintenance item, despite what the instructions say there is a preponderance of evidence to support getting it out of the engine bay, which should alleviate the requirement to retorque it

Welcome to the 'Place, Bradley..........

Three problems -

- the module\heatsink must be mounted far away from engine heat

- tightening the attaching screws did not fix anything - removing and replacing the mounting bolts re-established the ground for the FS, that black wire you removed from the top of the Inj Pump - it must be removed from the heatsink and grounded to the top of the IP - pull the wire back thru the harness so it will fit there, or you'll get intermittents till you sell the truck, in disgust.

- it is a heat SINK, just like the sinks in your house, and the heatsinks on your stereo, tv, guitar amplifier, etc - it functions to pull, or sink, the heat from the module and radiate it into the surrounding air - except when it's on top of the engine, there - then it sinks the heat from the hot engine and radiator and radiates it into the module.

- sync is synchronize, abbreviated, as in sync yer watches, gentlemen

Well, that's four - so, I lied..............

Point of order...

Heat flows downhill ... from hot objects to cold ones. For the heat sink to function, it must be cooler than the PMD.

As it absorbs PMD heat, the heat sink naturally warms up. The mass of the heat sink determines how fast this happens. If the heat sink has too little mass, it will warm up fast. If it reaches the same temp as the PMD, then it will no longer absorb PMD heat.

To avoid this unhappy situation, the heat sink must, in turn, radiate its absorbed heat out in another direction (ie: to the air). This is a function of (a) surface area of the heat sink- which is why some of them have fins - and (b) temperature of the ambient (surrounding) air.

If the surrounding air is HOT (as in UNDER THE HOOD), the heat sink cannot effectively radiate away the heat it has absorbed.

This makes it get warmer, until it approaches the temp of the PMD. Thich means it loses the ability to efficiently absorb PMD heat, and thus cool the PMD.

The Thermodynamics is simple, and yet people still insist on mounting their HeatSinks in hot places.

Think of it this way ... when it comes to heat sinks, if it ain't cool, it WON'T cool.

Thermodynamics 101 - 'Nuff said.

Well I'm at my wits end!

Should I replace the ignition switch, to correct the stalling problem?

I can get a new GM one for a good price under $200 cdn.

Went through the truck again with a DVM checking wiring from ground to computer wiring and PCM power wiring to ECM fuse, couldn't find anything obvious.

Sometimes it starts right away, sometimes have to wait for the lift pump to wake up (and WTS light depending on cold it is).

Some have said the ignition switch is also a weak are like the FSD!

If you have to wait for the lift pump to "wake up" when this happens work your way backwards with a volt meter to see where you have power (or dont) Im betting you will have nothing all the way back to the switch
I took a quick look at a wiring diagram and if I read it right you should have power at ECM B (orange wire) FUSE (under hood) and at the ign switch it should be a pink wire, hook a test lite to the pink wire and see if it lites/fails to lite while your trying to start it

I couldn't take it any more, I replaced the ignition switch (doing the stealer thing, just start replacing stuff).

Attach are pictures of the contact inside the switch and wiring.

The tape around the wiring is falling off and the tape sticky stuff is still oozing off and gets ones hands all dirty.

The contacts also have some burning hard to get a picture inside the switch housing.

Hoping I hit the jack pot with the ignition switch.

Good shot - show 'n tell rules ! ! !

Fairly well indicates the inherent problem in a contact-type switch as opposed to a wiper-type - planned obsolescence is the name of that game.

Here are the rest of the photos, from the ignition switch and harness.
It's hard to see inside the switch housing but could see some burning as well.
The tape goo was an interesting sign.

So far no stalling in the last 300 kms since the ignition switch change out.