shuts off sec after going WOT....why?

[fst]

just lately my car has been doing this. heres what happens-whenever i go full throttle and hit boost, after i let off the throttle a few seconds, anywhere from 2-5 seconds the motor stalls or turns off. the RPMs drop to zero, my fuel needle pegs full, my DIC flashes zero anf my dash lights up-CLE included.

i changed my CPS sensor and it still does it. this all seemed to happen after i swapped from my LQ4 maf to a LS1 maf which is smaller in diameter. reason why i swapped is because i was cracking LQ4 mafs cause of overtightening them to prevent them from popping off(the lq4s are plastic whereas the ls1 are metal).

i tried to scan the CEL once the car came to a complete stop but my LS1M even gets an error and reboots itself.

any ideas?

[fst]

also fwiw the ls1 had no screen. dunno if thats something important. honestly the car ran for a couple thousand miles like that before recently this all started.

[matt5112]

bad PCM?

have you tried using another one then flashing your current tune onto it?

[fst]

not yet. this pcm i've been using for a long while. its located right next to the coolant reservoir(my cars a 98) and next to it is my turbo intake piping fwiw. i got another pcm but for some reason its not a 98 year even though the previous owner says it is(my shifts and TC reacts akwardly).

[TheOtherNick]

sounds like a pcm issue, dic flashing 0 means it is in programing mode.

[matt5112]

Could you not re-write the entire PCM file based on whats on the one you have now?

[fst]

Could you not re-write the entire PCM file based on whats on the one you have now?

i dont understand what you mean? could u rephrase that?

[TheOtherNick]

He means do a write entire with the tuner. From what I understand you can dont rewrite a pcm from a different year car.

[fst]

you mean a full write reflash to my current pcm or into another pcm of the same year? still a tad confused on the wording here....prolly just me though Xp

[matt5112]

pretty much.

[TheOtherNick]

He meant rewrite the wrong year pcm with you file, which does not work, get a same year pcm and do a calibration only write it should fix you issue.

[matt5112]

Thanks for the info nick.

Is that for all years period though?

[TheOtherNick]

Not sure, I just know with hptuners you can not rewrite a different year pcm with a different year file.

[fst]

ok, then i guess i should look at another 98 gtp pcm to see if that'll work. so u think my current pcm is bad?

[matt5112]

I'd say start there.

[TheOtherNick]

I would say so, it seams like the pcm keeps going into programing mode and the car will not run when that happens.

[fst]

well i swapped pcms and did a full write to it via powertuner. took it out and drove around all day doing errands and whenever there was an open stretch of freeway i floored it. did it 4 times and not once did it stall on me. hoping it was the pcm but i'll check again today and put my doubts to rest =)

[matt5112]

Good to hear

still stuck at 14.6 PSI?

[fst]

actually the LS1M registers 14.39psi :-p
but yes you're correct. i dont know how to setup a 3 bar map sensor to the pcm but its kewl. i bought a boost gauge on ebay that has hi/lo peak warning as well as recall that has its own map sensor. its a marshall instruments scx pro street 2 or whatever. going to install it soon. want to be able to run 16-17psi daily if i can.

[matt5112]

Sounds good, let us know how it goes.