Stalling

[Rodd]

I just got the 1995 Sierra and it just started stalling. Is there a difference on how the lift pumps work in the 1995's and 1996-2000 models. The reason I as is because it has stalled on me twice, my wife once, and my son once. I think it is the LP. Just replaced it. The issue is on my 1998 sub and my (RIP) 1999 sub the lift pump clicks/vibrates when the wait to start light is cycling. In the Sierra nothing. I checked the t valve and fuel came out as a steady stream without stalling. I replaced it any way just in case it was going bad. Still silent no vibrating/clicking at all. Is this a problem?

 

[ak diesel driver]

pre 96 doesn't run the LP during wait to start. Also the OPS controls the LP where as the 96+ also uses the PCM. Buy leroy's relay kit with WTS added to it and you'll be good to go.

 

[Rodd]

Thanks! Is the kit you are talking about the"Lift pump relay kit with WTS priming?" So you think the OPS is causing the stall?

 

[WarWagon]

If you are going to throw parts at it start with a new PMD and extension harness. Checking/cleaning grounds, batteries and positive cables connections are free...

 

[ak diesel driver]

Thanks! Is the kit you are talking about the"Lift pump relay kit with WTS priming?" So you think the OPS is causing the stall?

Not necessarily I was just going off what you thought. PMD would've been my first thought

 

[Rodd]

I was thinking PMD but it acted like my other trucks when the LP went out. I'll throw my spare pmd in it and see what happens.

 

[Will L.]

That is where the beauty of a permanent fuel pressure gauge comes in to play. Diagnosed at a glance.