Only starts after block heater is plugged in

[Darkimag22]

And.....I'm back to square one. Truck sitting outside for 5 hours and same no start as before. I'm at a total loss now...damn it.

 

[Drunkcanuk]

That sucks AND blows at the same time!!! These trucks are like kids....they test your patience almost daily!!!

 

[PlayingWithTBI]

I'm back to square one. Truck sitting outside for 5 hours and same no start as before. I'm at a total loss now...damn it.

Sounds like it's time to put a scanner on it and see what's going on with all your sensors, RPM feedback, and outputs.

 

[Darkimag22]

If I can't figure it out by next Tuesday it's going to be dropped off at my mechanic.

I do have HPTuners. I've done a bit of logging in the past but could that show anything of interest or is an actual automotive tech scanner be needed?

 

[L31MaxExpress]

If I can't figure it out by next Tuesday it's going to be dropped off at my mechanic.

I do have HPTuners. I've done a bit of logging in the past but could that show anything of interest or is an actual automotive tech scanner be needed?

HP Tuners data is better if you log the correct stuff. Have it rolling when you crank it over. It will give details that a scanner does not have the update rate to see.

 

[RichLo]

Have you done tuning to it with HP tuners before or are you just going to use it as a data log? If tuned, maybe try a factory file in case there is some low temp gremlin hiding in there.

 

[Darkimag22]

I disabled the passlock as well as the downstream O2 sensors...that's it but I will go back to stock and see what happens.

 

[L31MaxExpress]

I disabled the VSS as well as the downstream O2 sensors...that's it but I will go back to stock and see what happens.

VSS is needed for idle. The IAC resets position when the vehicle is rolling at steady speed on throttle. Without it no IAC position resets, the PCM loses position of the IAC over time and the startup and idle quality tanks.

 

[Darkimag22]

My bad. It is the vehicle security I turned off...VATS...NOT VSS.

 

[someotherguy]

My bad. It is the vehicle security I turned off...VATS...NOT VSS.

I was starting to think that's what you meant, what with it being a '98 and all. Passlock is what that system is called. VATS is the old system with the "chip" (resistor) in the blade of the key; wasn't used in GMT400's.

Richard