FSD, Again. I have a question.

[danhercules]

I had my FSD replaced just before the 120k mile warranty expired. I now have 180k on the truck and I think it is going out again. There is 68k on this pump, Is it covered under waranty?

I did a search and having a hard time finding anything. I also cannot find on the members page. Thanks.

[More Power]

Generally no.... Once outside the GM extended warranty, you're on your own. Stanadyne issued a document back in 1998 that outlined its warranty policy (I have a copy), but it deals more with its relationship with GM than with consumers. When pressed some years ago to define their end-user warranty, they danced around the question like a politician.

I encourage owners to discuss pump warranty coverage/limits/exclusions with their servicing dealer or diesel garage before any non-warranty service work is performed.

MP

[Marty Lau]

Dan;
If it isn't covered why don't you change it out (PMD/FSD) yourself. The moduals run about $250-300 and you can get a remote kit and new modual for under $400. If is just the PMD/FSD I would be hard pressed to change out the whole pump.

[danhercules]

Originally posted by 16ga SxS:
Dan;
If it isn't covered why don't you change it out (PMD/FSD) yourself. The moduals run about $250-300 and you can get a remote kit and new modual for under $400. If is just the PMD/FSD I would be hard pressed to change out the whole pump. Now you got my attention. I dont know the diffrence. I read the members section, but I am confused. There are two things that go wrong? A modual and the pump? All the abbriviations got me going. I dont even really know what I am looking at or where the pump is.

I can change water pumps, I have pulled stantard tranies, bolt and unbolt things. Is this somthing I can do?

[whatnot]

If you want to spend time instead of money, you can pull it off the pump and check the 4 transistor nuts. I bet they are loose. If so, just re-tighten them and it will probably work fine again.
The better option is to buy a new one and a remote mount kit with cooler and leave the old one on the pump.

[Turbine Doc]

Dan
PMD/FSD are same animal it's function is a fuel solenoid driver FSD, mounted on side of IP where it is called Pump Mounted Driver PMD, many remote locate off pump on heat sink, in attempt to keep it cool & from failing. Lots of debate and thought on actual fail mode. Serch the forum you will find volumes on the subject.

FSDs do seem to last longer on heat sinks or "coolers", there have also been some FSD's brought back from the grave by retorqueing transistor mount screws on back of FSD/PMD under black caps.

[vernj4]

The better option is to buy a new one and a remote mount kit with cooler and leave the old one on the pump.

whatnot.....why leave the old one mounted to the pump? why not remove it; salvage it; and save it for a rainy day?

[Tony J.]

If the heat is the main issue, has anyone ever brought the harness through the firewall and mounted the FSD under the dash? Seems like it'd be WAYYYYY cooler than under the hood????

[danhercules]

I had my "pump" replaced by the dealer before the 120k cut off. Is this changing the FSD or the whole pump?


Just so I understand, what "might" be wrong with my truck now, is just the "computer" (the FSD) that is mounted on my injection pump?

If thats the case, just geting a new FSD (the computer module that is on the pump, right?) will most likly solve the problem?

Is it hard to unplug and plug the new one it? Its probally not the simple.

[rjwest]

Tony J YES. Mine is mounted right under the steering column, with a small fan facing to
right ( passenger ) I cut a small hole in Heater/ac
box, above lower outlet. This is the un directed
air area, Installed 90 PVC elbow. It blows
cold AC air at fan area.of FSD.....

In winter i tape over hole.

I can now let truck Idle with AC on in summer
to keep Wife Happy....

Outside temp probe of INside/outside temp gage
is stuck to top side FSD, stays below 100 deg.

I did have the remote mount under hood , with fan,

Still got hot when Climbing steep hill at low speeds, Did have a remote FSD fail this way.

[tom.mcinerney]

Dan--
1.) The electro-mechanical aspects of the fuel injection pumps frequently last longer than 80,000 miles. Use of quality fuel, without water, and with lubricity additives, helps. A healthy lift pump, maintaining the level of fuel tank above half-full, and carefully replacing the fuel filter (and draining water from housing, and bleeding air) also help.
2.) There are two fuel pumps on vehicle. A low-pressure priming (or 'feed' or 'lift') pump along the frame rail {C/K}, and a high-pressure, high precision Stanadyne FuelInjectionPump [aka=FIP].
The Stanadyne FIP is mounted in the vee, or valley of the V-8. The FIP has a primary vane-type pump that raises pressure to above 100psi, then more sophisticated gear to raise pressure to thousands of psi. The FIP includes a "Fuel Solenoid" VALVE which meters the amount of diesel to send along each fuel pipe to each fuel injector at each cylinder on every power stroke! In the OEM configuration, a PMD=FSD is mounted to the driver's side of the FIP.
3.) This item, the 'Pump-Mounted', or 'Fuel-Solenoid Driver' is an ELECTRONIC amplifier. It is very similar in function to the ELECTROMECHANICAL 'starter solenoid' used to amplify the ignition switch's signal to the starter-motor. This item, the PMD/FSD consists of 1-an electronic pulse circuit, 2-a pair of output POWER TRANSISTORS (called, in the trade, "DRIVER TRANSISTORS" or just 'drivers'), and 3-an integral heatsink, designed to mate with a larger heatsink, which would maintain the temperature of the module at a safe level. The heatsinks are heat exchangers (like radiators, they transfer heat). In the OEM array, the FSD is pump-mounted, the heat created by the inefficient bipolar drivers is transferred to the aluminum FIP housing, and thence to the fuel circulating within, and back to the tank...
4.) The 'brains of the operation' is the PCM/ECM. That is the PowertrainControlModule, or ElectronicControlModule. This is a small computer located over the heater in the passenger side of the cab (C/K). The computer [PCM] tells the FSD/PMD to give a kick in the buttox to the Fuel Solenoid, allowing a pulse of high-pressure fuel to escape the FIP, and spray out an injector.
5.)A poor battery/ground connection, or weak connection at any engine wire harness plug, can cause a FSD to missfire. (So can clogged fuel filter). FIPs should last 100k Miles, FSDs frequently last only 60K miles. For a few hundred dollars a FSD can be replaced, often allowing another 60,000-100,000 miles before renewal of the FIP(which is a few times more expensive).
6.) A few years back a Sweedish engineer known as 'Beta' designed, and manufactured to exacting standards, a heat-exchange/cool-plate or auxillary heat sink called an "FSD-Cooler". These, and similar contrivances, some home-built, have been used to remote-mount the FSD away from the OEM configuration on the FIP, preferably in a cooler location.
More recently Beta and his customers noted that the FSD-Cooler wasn't a permanent/perfect fix. Beta has designed and built, and is testing a far superior "FSD-module", which is not yet available. Both "GMCTD" and "Beta" independently discovered a repairable design/QC flaw in the present FSD/PMDs. The procedure involves snugging fastenings.
7.) If you decide to try replacing your FSD [after maintaining the fuel and electrical connections] you'll need a new FSD, and maybe a cooler and harness. It takes from one to several hours, depending on your situation and plan of action. Descriptions should be available in posts, and reference materials on the site [There's also a lot of high quality info/advice in Article Reprints of earlier TDP efforts].
8.) good luck, hope it works!

[danhercules]

Tom,

that was killer. Thanks.

Now that I understand better, I can talk and better terms.

I had the FIP, replaced at approx 190k, by the dealer, I asume they changed the FSD.

Truck has been fine until now. I checked the fuel filter 1st thing after the 1st stall. It was bad, real bad. I called my mecahanic, he told me he never changed it. I go there evey 5k and change the oil. He told me to have the filter chaged every 2 oil changes, (10k) Well, there was a miscoumunication, it was never done. I changed it when I 1st got the truck, at 115k. So its been a while.

Yesterday it died 3 time, almost not starting again.

I hear the lift pump when I trun the key, (is that the lift pump?)


What is the 1st thing to check under my conditions.

PS. I got the tuck Hot about 4 months ago, Just under the orange on the gauge. Could that have coused premature FSD failer?

Thanks for all the help, I dont think I have ever learned so much in 3 days!!! I am gettin ready to sell the truck so I want it to be good for the new owener. (04 on the way)

[danhercules]

Can pulling up the codes on the truck tell me whats exactly wrong, or at least tell me where to start, rather then just trying to guess where the problem is?

[Beedee]

This is a great thread guys, I've been following it and several like it for a while. Thanks for the explanations. Its stuff like this that makes the Diesel Pages such a kick ass site. :D
Thanks
Beedee
:cool:

[danhercules]

Originally posted by Beedee:
This is a great thread guys, I've been following it and several like it for a while. Thanks for the explanations. Its stuff like this that makes the Diesel Pages such a kick ass site. :D
Thanks
Beedee
:cool: I agree. I like the members area, but I dont know if I am understanding it like its suppost to be understood. Now that I know more, and I read it again, I understand it better.

Whoever I sell my truck to, I will be sure to tell them about this site.

[danhercules]

Update.


I took it to the shop to get the codes read. Came back with somthin along the lines of the cooling system. My guy suggested to change out the themestats. So I said OK. I have been driving it for a week, and no more stalling.

Is this a normal thing? Now I am really confused!!!

[Marty Lau]

Dan;
These things are gremlins and can reappear after time. I would suggest that you clean all grounds and electrcal conections as a preventivie thing. If it is the FSD/PMD then it's just a matter of time and you will have problems again. If your truck was running hot that could have started the chain of problems. I would make a plan to replace the PMD/FSD either plan on putting it back on the pump or remote mount it out of the engine bay. DO NOT put it on a heat sink mounted on the intake manifold. Many people have had the FSD/PMD die with that install after 25,000 to 40,000 miles.
In my opinion you have enough miles on the IP that the FSD/PMD death is not that far in the future so be prepared.