I have a1996 gmc k3500 6.5. It stalls. Drives fine then stalls turn igntion off and then back on no glow plugs no starting. turns over tho. my service engine light flickers. open the hood the fuel pump relay clicks eratically on and off (cause of the service engine light i believe) not the pmd i've already plugged another in with no change in results. just changed the fuel pump and it has died on me once but fired right back up still rolling. Any help would be great

 

Check the wiring for the LP relay and/or replace the relay.

There is not a trouble code for LP operation.

What trouble codes are being stored?

 

p0231. definitly short in lp wiring system. died wouldnt start at all unplugged the lp and started up. died now (2days later) will not fire at all. turns over fine and fast enough

 

P0231 Fuel Pump Feedback Circuit Low Voltage

That code is not for the LP,it is for the IP.
The feedback circuit runs through the PMD.

By unplugging the LP you have only made work harder for the IP.

 

yes i do realize this. also when plugging the new LP in i could not here it. and i have plugged a different pmd in and no different result