Difference Between 6.5TD Fuel Solenoid and Fuel Shutoff Solenoid?

[Blackie94TD]

I have a 94 Chev 6.5TD. Many mods have been made including cooling system upgrade, remote mounting PMD, marine injectors, HP glow plugs, increased HP ECM chip, and more. I continue to get DTC 36 but only through certain rpm range(1800-2500) and only when the engine is cold. I have tried everything suggested in Jim's article on the DTC 36 problems including fuel system inspection, ground wire connections, and cleaned and DE greased the 15 pin connector....still no luck.

The truck runs great except for a very slight stutter occasionally a idle that I credit to the marine injectors. The truck has tremendous power and has leterally been upgraded to hot rod status. I just wish I could get it to quit posting an intermittant DTC36.

Question: Chevy service manual for the 94 6.5TD diesel states there could be a problem with the fuel solenoid(not to be confused with the FSD). I know there is a fuel shutoff solenoid( canister shaped on top side of IP) that I have already replaced. Instructions in the manual say to inspect the fuel solenoid and associated wiring for poor connection. I would love to do that if I knew the location fuel solenoid. Can anyone tell me where the fuel solenoid is located????

Any other suggestions would be greatly appreciated.

Thanks,

Blackie94TD

[gmctd]

The Fuel Solenoid Driver drives the Fuel Solenoid
- it is:
- not field replaceable
- down in back of the IP, in amongst the 8 injector ports

The fuel shutoff solenoid is called the Engine Shut Off solenoid in the DS4 system

[Blackie94TD]

Thank you very much for your help!

[gmctd]

The Optic Sensor is top of the IP, 6wires to the connector.

The '94 OS harness has a rectangular black module plugged in between it and the engine harness - the OS Filter - try removing the module, direct connecting the OS connector to the engine harness connector for a while, see how that works fer ya - any improvement or worse, HeathDiesel sells the replacement

Could also be the 100kmi DS4 needs replacing, but try the filter, first.

[Blackie94TD]

I will try that. Thanks again for your help. I agree with your thinking! The DTC 36 is intermittant. The light will go on and off as it passes through the 1800 - 2400 RPM range. I can't help but feel the problem is an electrical connection issue of some sort. The pump only has about 20K on it and the last five have been with a remote PMD.

[gmctd]

Ok, my bad - twisted the mileage numbers around on the IP

Did you extend the IP harness to remote mount the FSD module?

Where is the short black ground wire that was originally attached on the top of the IP?