Truck just down confirm PMD/FSD

[Hubert]

97 K2500 ~ ~120,000 ish miles runs and cranks fine normally. Runs strong no bad smoke etc.

Dang! I just posted. Ole Murphy got me. No more homework I was working on a heat sink at work for remote mount fsd and leaving work my truck wouldn't start! Anything I miss I am 99% sure (I am rarely 100% sure of anything) its the FSD. Make sure I did not miss anything here.

Checked volt meter frt driverside glow plug shows ~ 12V when wts light on.
LP working fuel comes out air bleed.
Batteries good cranking regular speed. Outside ~mid 60F temp. Truck usually cranks easily.
I loosened frt driverside injector line. No fuel while cranking. Conservatively we cranked it over a minute and no fuel coming out line. Pulled line away and some diesel bubbled back up injector while cranking but none out steel line.

I have had a recent couple of cases of long cranking and finally started and ran normal. Had one a yr ago and another 6 months ago. Yesterday, I cranked ~10 sec no start cut switch immediately (just changed grip on ign. switch) recranked and it fired right off. Also, recently a few intermittent jolts or bumps going up hill cresting a hill on cruise and under light acceleration and the odd one just driving unexplained. One cut off idling at a stop sign shortly after startup driving to work. It immediately restarted and ran normal. The filter is brand new last night and the truck ran fine last night and to work ~ 50 miles on filter. The filter I just replaced was only ~ 5,000 miles old and looked clean (I was trying to eliminate things before spending big $). Fuel cap not clogged passed a blow suck test felt like a SCUBA regulator with exhaust plugged. Checked codes last night with Actron OBD-II Autozone reader no codes no SES light.

Classic FSD failure symptoms huh anything else besides grounds and connections?

Thanks for replys. It sure would make me feel better about a couple hundred dollar gamble purchase.

Hubert

[rameye]

I'm wondering about this statement..

"I loosened frt driverside injector line. No fuel while cranking. Conservatively we cranked it over a minute and no fuel coming out line. Pulled line away and some diesel bubbled back up injector while cranking but none out steel line."

I would think that some fuel should would weep out of lines when they are cracked.

In the interest of ruling out possibilities...just crack the injector line, crank it over and let ud know if fuel weeps out.

Stay on this..

[Hubert]

Cracking the line and cranking it should weep a little diesel not much but some. Not getting any tells me the FSD is not communicating and opening the fuel solenoid and/or what ever commanding the IP to start metering fuel out to run the engine. The truck runs too good for the IP to just die that quickly with no codes???

Anything else I can check? A little snake oil starting aid (not ether!) in the turbo inlet with care after WTS light off help fire it off some and see what happens?

[twaddle]

Hi Hubert,
What!!! you don't have a spare PMD/FSD???

I thought having a spare PMD, OPS, lift pump, multi meter, tow rope etc etc were all part of owning the 6.5's with electronic fuel pump.

It sounds to me like PMD failure, is the lift pump buzzing when you turn on the ignition?

Also check for any broken wires or poor connections.

Good luck

Jim Twaddle
Biggar,
Scotland.

[twaddle]

Hi Hubert,
What!!! you don't have a spare PMD/FSD???

I thought having a spare PMD, OPS, lift pump, multi meter, tow rope etc etc were all part of owning the 6.5's with electronic fuel pump.

It sounds to me like PMD failure, is the lift pump buzzing when you turn on the ignition?

Also check for any broken wires or poor connections.

Good luck

Jim Twaddle
Biggar,
Scotland.

[Barry Nave]

Also make sure fuel shutoff solenoid is working

[Hubert]

How do you check the fuel solenoid itself. I thought on the DS-4 it was considered intergral to the pump and not serviceable.

[rameye]

there is a fuse for the fuel shut off solenoid on mine..

you should hear it make a distinctive click when the key is engaged..

give it a tap( lightly) they can stick..

good luck

[Hubert]

Thanks sounds like a good check. I'll do that.

But....

Straighten me out here if I am wrong. I have tried to read most posts but a search with FSD PMD or solenoid as a key word returns too much.

I thought on the DS-4 the PMD/FSD commands fuel flow and via the the Fuel solenoid and something else. But the fuel solenoid doesn't necessarily shut fuel off as in the mechanism for cutting engine off it is a metering mechanism??? Or can it stick completely closed?

On the older pumps it is the mechanism for shutting down the engine right ???

[Hubert]

What does this tell me?

I had tried to crank first thing this morning having done nothing overnight. It did not start.

After reading replys I took cover off main fuse box under the hood and wiggled the Fuel pump relay (? what does this relay control the lift pump was working yesterday for sure diesel out top of filter with switch on). It was the relay to the inside and towards the front of truck beside the horn relay. Also, I lightly tapped fuel solenoid on its top while a friend tried to crank it and it sputtered just a little bit and cranked up nicely ran smooth! Its running in the parking lot now charging batteries back up.

If the solenoid is sticky or stuck would it set a code? Maybe the Actron OBD-II reader I have won't read diesel specific codes? But no SES light!

I still think its an intermittent PMD problem (Ughh)OR fuel solenoid itself and/or connections.

What exactly is this relay? Was that a coincidence? Next time how do I check this relay. I did not want to tug it too hard. Does it just pull out? 12V across what pins closes the relay. Can I bench test it with 12V battery power.

Changing the fuel solenoid is it just screw off and screw on another one. If its that simple why does the stealer not sell that part only?

Thanks guys!!

[rameye]

I may be a liitle out of my league here...so please correct me if I'm wrong...my wife always does!

"What exactly is this relay? Was that a coincidence? Next time how do I check this relay. I did not want to tug it too hard. Does it just pull out? 12V across what pins closes the relay. Can I bench test it with 12V battery power."

The relay under that cover is the fuel pump relay. It recieves a signal from more than one source and energizes the lift pump. Your ECM may turn it on, the crank circuit may turn it on, the OPS may activate it depending on year.

Its mechanical..it can stick and go bad...yes if you just tug on it it will come out..no harm.

The fuel stop solenoid...what you tapped, is what gives the inj pump its fuel. The computer controls it. Doesnt like whats going on and it closes it...no fuel. I beleive its open when energized and closed..no fuel when de-energized. One fella on other post summed it up well...when the puter doesm't like what the PMD is telling it it pull the plug on the fuel and she dies.

From what I've absorbed on this board this solenoid can stick in the off position..apparently it can be replaced.

Non- guru response here I've still got some years to learn.

Glad its running

[rameye]

One more thing...no if the solenkoid is bad it wont necesarrily set a code...

that makes it funnerer

[Hubert]

OK it cranked afterwork and driving home it cut off at one stoplight cranked right back up and had one jolt/bump driving low rpm 5th gear down a hill light throttle. Still no SES light.

Hmmm gotta be the pmd acting up.

I can see a stuck fuel solenoid not allowing it to start but will one fail and cause shut down and crank right back up? Anyone experience that?

I think earlier today was a coincidence tapping the solenoid.

Still could be some connector but I can't drive it like this. No way around it gotta get some spare parts and join the spare parts toters club.

[moondoggie]

Good Day!

[i]

[Barry Nave]

Hubert
Have you read up on past post where you lossen the screws on the fsd transistor and retighten? Remove the black covers, may have already done that.
This has worked for some fsd.
I also had the same problem years ago and the fsd slowly died out.

[rameye]

Moondoggie makes a good point for it to be the FSD.

As I'm sure you've read...checking the grounds and wires is most important as this is an intermittent.

New one with extension harness...sol-d.

ram