Whats the problem here? 1996 chevy turbo diesel?

[JQA3]

134k miles, will only fire when the oil pressure gage reached around 40. starts every time when the gage is up to 40, will not fire if that gage isn't at 40 when cranking.

134k miles, will only fire when the oil pressure gage reached around 40. starts every time when the gage is up to 40, will not fire if that gage isn't at 40 when cranking.

the engine runs fine after its started, if you shut it off, the start it, it will start, if the oil gage is at zero, it will not start. Also i cycled the glow plugs several times as you described and it doesnt make a difference. The batteries in it are duralas golds, 1000 CA at 32 degrees, replaced a year ago. How could i know for sure whats going bad? any way to check?

[ScottH]

Your motor works off oil pressure .....The HPOP --high pressure oil pump is what fires the injectors delivering fuel to the motor. You may have a weak pump or injection control pressure sensor going bad.that is related to the oil pressure anyway. You may have weak glow plugs with the colder weather setting in. Try cycling from off to acc position with the key 3-4 times before actually cranking. Could also be batteries are weak and not giving a full hot to the glow plugs.

[CLAYTONM]

oil pump or gage

[CLAYTONM]

oil pump or gage

[CLAYTONM]

oil pump or gage