fuel solenoid

[russfixr]

Truck recently quit on tollway in the middle of the night with loaded horse trailer. Without going into detail on troubleshooting, I eventually determined the fuel solenoid on top of the injection pump was getting a signal (12 volts) but not opening. I was somewhat desparate, so I pulled out the "guts" and put it back on. The truck runs same as always and shuts down just fine. 2 questions:

1. Whats the purpose of the solenoid valve since it runs the same without it?
2. The dealers I got in touch with in the moning told me the solenoid is not listed as a separate part and I would have to buy the entire pump. Has anyone had any experience with this?

thanks

[jdmetcalf57]

Thank God for the diesel page!!! I don't think a lot of dealers know much about the 6.5. I just took mine into a dealer because of the PMD failing. They replaced the PMD and the fuel shutoff solenoid. They did not replace the pump.

I need to investigate this further because I read on tdp that it is supposed to be replaced as a unit for warranty.

[Marty Lau]

russfixr;

Try this link for what your looking for.

http://dieselhelp.com/gmc-9.html

[Turbine Doc]

JD you got to remember to GM the 6.5 is an "Old obsolete" product, very little schooling on them for their techs, most have moved on to DMax, if you have a dealer nearby that moves a lot of Hummers, they should have someone up to speed on 6.5.

Under special bulletin, you should have gotten both the IP & and the PMD. go to the members reference section and read the policy, you should get the IP also, they probably won't set the TDC offset even if they know how to -1.94 nothing in their book says that is okay.

Once you get your new IP find someone with a tech 2 or Snap On MT2500 and it can be reset fairly easy, easier with T2 as that is the GM tool, I've only done myself it with MT2500.

[Turbine Doc]

Russ you pulling the solenoid or PMD, PMD controls the solenoid, driver is a separate item, how many miles on your truck, should be covered by GM for up to 120K mi.

Both you & JD need to take a moment to update your profile so you don't have to keep saying in your post intro what rig you have, plus it helps us to help you, if you say I have a 95 we know it's OBDI, and 96 it's OBDII in some circumstances a little different troubleshooting proceduere.

Also visit RPO code list in the members reference area, in your glove box is a sticker bunch of codes that has info of what your truck came with from the factory.

[russfixr]

I guess I should have included more troubleshooting notes. I had a spare PMD with me since I have already been that route before. I also keep it mounted on the manifold mounted air cooler. I had no codes on the OBDII. I'll be getting with a dealer in the morning on the replacement since I'm at 115k miles. At least pulling the valve stem got me home. Makes one wonder about the usefullness of the whole solenoid thing. Thanks for the feedback.

[rjwest]

Standyne dealers have the solenoid, I carry a spare...

[JohnC]

On the EFI trucks the shutoff solenoid is a (necessary) safety item. One of the failure modes of the FSD is engine runaway. When that happens (or when the PCM thinks it may be about to happen, as in PMD failure) the PCM commands the fuel shutoff solenoid closed, hense the "stalling". Inconvient most of the time, but nice if the engine really runs away...

[Hubert]

97 K2500
What's involved in replacing the Fuel Solenoid? What's the part number and about how much do they cost.

Looks like an allen key in top might unscrew it?? But I thought it was not servicable and considered integral to the pump?

[BobND]

There's 2 solenoids... the fuel solenoid that controls high pressure fuel delivery, and the fuel shutdown solenoid.

Replacing the fuel solenoid in the pump high-pressure head requires special adjustments on a pump test rig.

Replacing the fuel shutdown solenoid on top of the pump is a simple matter of unscrewing the old one and replacing it with the new one.