97 Silverado 6.5l turbo diesel no start problems. 135k miles. Running fine until a few weeks ago. Stopped for no reason, suspected gas contamination (still not sure if it was). Fuel emptied and fresh diesel filled. Was very hard to start but once started, ran fine for a week. A week ago, no start, and after extended cranking, started and ran fine for a day. Now, now start ...
Background: new PMD installed 3 years ago (remote location with heat sink) after a intermittent start condition.
Codes: P-1218 showing on MT2500. Resistor has never been installed in the PMD and has run fine without it for 3 years. No CEL.
Tested: Lift pump runs, Glow plugs cycle, fuel flows from T handle drain when key turned.
Return line on pump flows freely (tested with fuel overflow running to catch can while cranking).
Fuel shut off solenoid - piston removed yesterday (appeared functioning prior to removal) - #1 injector removed and engine
cranked for 3 minutes in 30 second crank/5 minute wait to clear air from IP.
No flow at #1 injector during the above, or since.
A to ground = 1.2v
D to ground = 12v
C to batt DVM ground = 12v
B & F = 0.6-0.9 VAC cranking.
Still No Start!!! Not sure what to do next. I have SO MT2500 with correct GM primary and troubleshooting carts, but not sure what to look for ...