does the 1995 h1 have a pmd on it? i've been looking at the pictures and it says it is about the size of a deck of cards. i don't see one on the injection pump and i can't find it. i don't even know if the 95's have one do ya'll know? also would an oil pressure switch sensor cause it to stall and be very hard to start back up, lack power, and blow white smoke?

 

no.. you don't have a PMD (only TD have this)... oil pressure switch can cause your truck not to start.... you might have a weak / deadlift pump.... I would check that first... other then that, you may have a injector pump starting to go.....

 

is the lift pump a cylnder with an inlet and outlet fuel lines and electrical connector? if so i have replaced it and no help, i'm not getting any power to the lift pump if that's what i changed, when the key is first turned on or during it sitting there idioling. would the glow plugs have anything to do with this problem? I did here from a gm mechanic that the injector pumps go out alot but it's only got 25000 miles on it, hoping it's not the injector pump.

 

yes that round thing if your lift pump..... you need to check your ift pump circuit, its likely a oil pressure switch problem.... as you should have power....

your glow plugs will only cycle, first at start up and for the next min or so as needed.... otherwise they are off.....

 

where and how do you check the lift pump circuit and is the oil pressure switch costly and hard to fix?

 

When you key up, there should be power to your lift pump. If you check the wires to the lift pump, you should be able to get 12v. If you don't see that, then the OPS (oil pressure switch) has likely failed. If you do get 12v, then you have a bad lift pump if its not vibrating when you key up.

I don't have the service manual for the '95 in front of me, but as I recall its located in the valley at the back of the engine........

 

Did you ever figure out the issue? I am having the same problems.