Need advice on possible failing FSD

[jdmetcalf57]

'99 K3500 87000 miles pump was replaced at 57000.

I am getting ready to leave on a big trip to CO and Utah from IL. My truck died 4 times a couple of days ago while driving. It would restart after a couple of tries. It wasn't particularly hot neither was I pulling very hard.

I have checked fuel pressure and most of the things recommended for stalling problems. I then took it to the dealer and he said it had no codes stored but he has saw the crank sensor cause this problem and reccommend it be replaced which I am having done.

If I can't get the problem to happen again before I leave what will happen if it starts failing while I am on the road. Will I be stranded or will it just continue to die and restart? How does FSD death progress?

Also the service manual says to remove the ECM fuse when checking fuel pressure which I did. Do the codes hold in this case or did I erase them?

For any with a FSD cooler. Do you have to remove the old one to use the cooler? It may be prudent for me to buy a FSD and cooler to connect up on the road if it will function adequately without doing any of the relearn stuff. Does anyone know if this will work?

[Marty Lau]

I have had a couple of PMD/FSD failures and how it went for me is that it would stall and restart after a brief time to start then the stalls happened more often and you had to wait longer for the FSD to cool off. If I was you I'd call Bill Heath from Heath Diesel and get him to overnight a PMD Issolater to you. You can install it in an hour or two and be more confortable on your trip.

[MTTwister]

No - you don't have to remove the old one - you plug in the extension harness to the connector on the IP mounted FSD and leave that one in place. Heath supplies a 6' extension cord for this purpose. Locate the new cooler in cooler air flow, I put mine on the splash shield under the radiator. ( T'ain't a stone guard, mine was high quality plastic :( )

[CareyWeber]

jdmetcalf57,

This may not be your problem, but it shows that wiring problems can cause many issues.

http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=006367

I'd bet that many pumps / fsd's have been replaced when wiring was the real issue.

Other things to look at are:
All battery connections
ALL GROUNDS
ALL GROUNDS
ALL GROUNDS
Did I say ALL GROUNDS ;)
The cable from the alternator to the battery.

After finding my wiring issue I drove from Hopkins, SC to Montana and back (thats the worst thing having to come back to this terrible place, but Uncle Sam says so) with know issues at all.

Carey

[HowieE]

I agree that it is most likely your FSD starting to head South.
If you want to see pics of an on the road fix take a look at my site.
If you have not already had a remote cooler the problem with and on the road fix is you will have to wait ubtill the engine cools down to get your hand down into the pump and remove the harness. It is very tight but with a long screwdriver to release the clip you can remoe the harness directly from the pump.