MrHorsepowerLSx

iTrader: (13)

I’ll make this short

02 Silverado with every power option except seats

I have owned this truck for 7 years and it has been through many stages, everything in the truck works like it is supposed to. Yesterday I took the truck to the dyno for a tune up, I drove the truck there, I swapped my injectors out at the dyno and installed ID1000’s, I drove the truck on the dyno, then shut it off. I hooked up the HPT, read and saved the file. The truck then would not start. It would crank and quick fire and die, I went over entire truck for about 5 hours. I swapped original tune back in, swapped injectors back in, check for injector pulse with noid light(good) checked spark(good) VATS is disabled and also passed the check when enabled, I have 2x pumps in my tank, I wire 1x pump to run constantly for fuel pressure, still no start. I even swapped ECM’s, same results. Here is the kicker. Truck put back to where it was when I drove it to the dyno, sprayed a bit of either and got truck to stay running it would then start and stop totally fine until the ECM for reflashed. Then I would have to assist the truck with a bit of either to get it to run, and then it would be totally fine.


Anyone have an issue like this? Im thinking perhaps a voltage drop across The ignition switch, or something with startup on the injector drivers, or communication between the BCM/ECM


Any help or thoughts is greatly appreciated


Thanks guys

Atomic

iTrader: (42)

We talked about it on the phone but seeing if anyone else has solved this mystery.

1FastBrick

iTrader: (17)

I saw a thread on tech where someone was having a similar issue after using one of the newer versions of HPT.

https://ls1tech.com/forums/pcm-diagn...w-log-etc.html

smokeshow

iTrader: (16)

I've had this problem a bunch on Gen 3 stuff. Never found a solution. Was stranded at a gas station for like an hour once. My only fix was to keep trying to start it and eventually it would work. Always tended to happen after flashing a file in. I'm sure there's a solution but I've never dug deep enough to find out what it is.

Atomic

iTrader: (42)

Me too. I used my meth kit test button as starting fluid basically, worked pretty well.

MrHorsepowerLSx

iTrader: (13)

My truck has no issues taking a tune, it is after it is flashed that it will not start unless a little assistance is used then it will start with all the time without issues

RDF1

7 or 8 years ago my silverado would do that with EFI Live.
Stopped at a gas station to fill up, adjust the tune some, flash it in and no start. Could flash that tune in 20 times and no difference.
Go back to a older tune, flash it in and it would crank and run just fine. Then i could flash in my updated tune that originally wouldnt crank on, it would fire up and run just fine.
Maybe some kinda data interruption?

Had one time i got a phone call while flashing in a tune and it took forever to get it to crank with different tunes.
Sometimes a full flash would do the trick. Dunno what thats called with HPT though.

madmann26

iTrader: (7)

write entire in HPT.

1FastBrick

iTrader: (17)

Just thought of something with 99-02 trucks.

When is the last time you cleaned the throttle body?

I wonder if the IAC passage is blocked.

MrHorsepowerLSx

iTrader: (13)

I have a new ( 1 year old ) ACDelco IAC valve and 1x year old FAST 92mm TB on it and I put maybe 400 miles on it since last year. But I had the TB all apartand cleaned just before going to dyno, it was cleaner then a baby’s butt