Seems like I’m having the same problem. I’ll give history on the truck because that might give some critical information . It’s a 1998 GMC Sierra C1500 , little 305. Truck came from Orlando and is the cleanest most rust and corrosion free truck I have seen . It has 180k milage and looks like the owner took good care of it and had it serviced routinely.
This truck was parked in 2014 . It was running and driving perfectly at the time . The past ( and original) owner just replaced it and didn’t sell it until 2020 . The past owner would start it from time to time and occasionally used it to pick up branches from the back yard . I acquired it started up instantly and ran like a new truck . I Didn’t end up doing anything with it until recently .
I ran into this starting and instantly dying as the truck was parked in my garage . I figured it was due to me leaving the battery disconnected, because it seemed to happen more often initially after hooking up the battery.
So now new battery , and the problem is very much unpredictable. I believe I have put about 1000 miles on it , and it’s been driven in rain , and smoldering hot weather . I don’t believe moisture is a problem but I’m not sure . Once it starts it always runs with out fail , runs smooth and steady until I turn it off . But occasionally it will start and instantly die . I have read posts about the passlock being problematic in this trucks of this year , but I am unclear and don’t want to start adding resistors or changing components until I know what it is . When it dies I will try again with no success . The only thing that works is waiting a untold amount of time. My daughter is turning 16 soon and I’m working the kinks out of this truck for her to drive ,
So when it chooses to no run , I grab my truck and go.
I’ve tried the passlock relearn but no success , I’ve read that the truck should run for 10 Seconds or so if it’s a security problem . I’ve also read the lack of oil pressure will disengage the fuel
Pump after it starts . My gauge hits 40lbs on cranking . Last night I was gonna run out for a can of dip and it wouldn’t start , and this morning is still won’t start .
And that’s the first time that giving it time
Didn’t temporarily cure the problem.
Im a small engine tech so I am pretty good at diagnostics, have most of the tools to do what ever . I’ve tested the fuel pressure and it’s great at 60 lbs . I hear the pump turn on .. There are no codes what so ever . And like I said once it starts it runs like a brand new truck .
Thanks in advance for any help you can offer . I’ll try to post a small video showing you what it’s doing . Can’t seem to find a option for videos . Is there one ?