My 98 K2500 starts and then dies, new ac delco fuel pump, fuel pressure builds up to 64 lbs, and the slowly drops off over time. Fuses all good, check

[618 Syndicate]

Black Bear seems to be the go-to for tuning the black boxes

They are the standard for black boxes, but @Dropped88 uses HP tuners to tune the 98+ trucks. He's honest and reliable.
And an all around good guy.

 

[McDermott]

So this is what I have done per reading relearn and reset.
Try to start the truck , starts and dies . I beg and plead with the GM gods to just let the madness stop lol . Try a few more times , then swear . Try one last
Time and leave the key on , then I’ve gone away with a timer set and returned after 10 minutes and it’s still on. I will try it again when I get home from work .
There have been different ideas on the reset .
So if I get the light to go off , do I try
To start it ? Or key off and on and wait again ?
And how long do I leave it off for ? Some say 5 seconds , some say 20 . Does it matter ?

 

[1998_K1500_Sub]

You can tune the truck to bypass that ? No need to put in resistors and all that ? That seems better . Do you have any suggestions to where ?

You can do it yourself easily using Jet’s “Dynamic Spectrum Tuner“ (which is what I used) and probably other self-tuner options.

Follow this link and read through the various discussions:

Post in thread '1998 2 door tahoe'
https://www.gmt400.com/threads/1998-2-door-tahoe.59174/post-1258916

 

[Airmanwoody]

Don't get obsessed with 10 minutes. I've had a few over the years that required more before the light went out. I just put a trickle charger under the hood and would check them every once in awhile until it's out.

I think the worst one took 45 minutes once. It was an 07 Hummer H3 that randomly had issues with it's security system.

 

[618 Syndicate]

Don't get obsessed with 10 minutes. I've had a few over the years that required more before the light went out. I just put a trickle charger under the hood and would check them every once in awhile until it's out.

I think the worst one took 45 minutes once. It was an 07 Hummer H3 that randomly had issues with it's security system.

Agreed on the charger

 

[618 Syndicate]

So this is what I have done per reading relearn and reset.
Try to start the truck , starts and dies . I beg and plead with the GM gods to just let the madness stop lol . Try a few more times , then swear . Try one last
Time and leave the key on , then I’ve gone away with a timer set and returned after 10 minutes and it’s still on. I will try it again when I get home from work .
There have been different ideas on the reset .
So if I get the light to go off , do I try
To start it ? Or key off and on and wait again ?
And how long do I leave it off for ? Some say 5 seconds , some say 20 . Does it matter ?

***Do not try and start the truck***
Key on. Wait until light goes out. Key off.
Key on. Wait until light goes out. Key off.
Key on. Wait until light goes out. Key off.
Start truck.

 

[McDermott]

So update . I get home and it fires up with no problem. I didn’t mention it before because I didn’t think it was a factor . But I removed the seats and counsel and did a full carpet shampooing . When I went to take it to the store the windows were fogged and there was a lot of moisture that was still there in the morning as I went to work . It fits that the 24 year old wiring , in a very damp environment would changed the resistance enough to throw it off. Do you guys also think that fits ?

 

[Airmanwoody]

If your security light is on, then no. Security light means you have a security problem, period.

 

[618 Syndicate]

Passlock problems can be intermittent, but as stated above the light is your clue.