car wont start

[BKrause]

just got my pcm tuned last week, im currently using a 2002 ls1 pcm on my 99 trans am.. and today when i started it and i was backing out it like wanted to stall on me.. everytime i pressed the gas it wanted to stall.. so i drove it down the road and went to turn around and come back home and when i put it in reverse and gave it the gas it stalled.. so i WOT on my way home and then it started again fine and drove fine.. drove up town like 5 miles just fine then 5 hours later i went to leave and it was doing it again.. this time it just shut off while i was driving.. so i pulled over and kept trying to start it and it wouldn't stay running then finally it ran fine and i drove it like 500 feet and it backfired extremely loud... 1 huge boom.. then stalled again then i waited 5 min and it started up fine and drove it home.. now its sitting in my driveway and i have no idea.. i don't know if it has something to do with the fuel filter, pcm, maf..

--ok got an update, i was gonna push my luck and drive it up to autozone to get the service engine code but now it wont even stay running for 3-4 seconds after i start it.. tried about 10 times now even waiting 15 minutes and checked everything under the hood.. everything is fine all cables, plugs,hoses.. everything.. but now it wont even stay running for longer than 5 seconds tops. it just stalls out after starting.. and im not even pushin the gas. its in park

update #2 car wont start.. removed fuel pump relay and changed fuel filter put it relay back in and still wouldn't start.. it cranks but will not start.. i don't know where to begin..

[1BADAIR]

who tuned it?
the plugs are probably toast but unplug the maf and try to start it
also check the eng sen fuse. it powers the maf and 02's. if it wasnt tuned well it wont want to run in speed density

[BKrause]

its been running perfectly fine for just over 1 week, iv driven 600 miles with no problems. i will check all that stuff tomorrow, thanks for the input

1badls1tuningsolutions tuned it, hes a sponsor on ls1tech. the tune is amazing. woke my car up so much and he is really good to work with, he sent me the 02 pcm so i could put it in while i drive my car then mail my pcm to him after i recieve the 02 one.. my car is a daily driver so i can't go without it. and the 02 pcm with the tune that i wanted worked fine so he told me to just keep it..

[1BADAIR]

whats done to the car?
headers with 02 extentions?

[BKrause]

nope mac midlengths didn't need o2 extensions.. car just has slp lid, mac mids, slp exhaust dumped right at the y..other little stuff

[Dudek]

just to clearify...you said you pulled the relay and put it back in but no start...you do hear the fuel pump start when you turn the key to the on position?

[gary]

SES light on? Check connections at PCM, O2 etc. If all else fails give us a call at the shop.
We can even pick your car up with our flat bed.
Davison - 810.412.5198
Swartz Creek - 810.635.3434
http://www.engineeredvictories.com/

[BKrause]

ok i can hear the pump prime but only for like 2 seconds.. i actually unhooked the gas line where the fuel filter is and then turned the key and it shoots out a little gas for like 1 second then stops.. isn't it supposed to be a non stop flow?

[gary]

ok i can hear the pump prime but only for like 2 seconds.. i actually unhooked the gas line where the fuel filter is and then turned the key and it shoots out a little gas for like 1 second then stops.. isn't it supposed to be a non stop flow?

When the key is turned to the run position the fuel pump will cycle on for a few seconds to build pressure then will turn off.

[BKrause]

i dont get it then? where do i start now?

[gary]

Its kind of a guessing game at this point. Check fuel pressure 50 to 60 psi with key on 53 to 65 psi running. Does it have spark? Are all of your electrical connections good?

Call us at the shop and we will get you in.
Talk to Mark and tell him I said we will give you a mifbody discount.
810.412.5198

[DETROITMUSCLE]

whats the last few things you did to the car? It could be a number of electrical things as well check all your grounds.

[BKrause]

the last thing i did was the pcm last week

[meissen]

Hold up - did you say you had to push WOT to get the car to start?

so i WOT on my way home and then it started again fine and drove fine.

WOT (mashing the pedal to the floor) when starting the engine sends a "Clear flood" signal to the PCM, it cuts the fuel injectors off and allows the engine to flush the fuel out of the cylinders. Honestly it sounds like your engine is getting flooded - you said every time you touched the gas in reverse it stalls, you had to WOT to get it to run (clear flood), etc etc.

Pull your spark plugs and smell for gas. Maybe you have a leaking injector?

[BKrause]

noo i just wot hoping it would clear something up if anything was wrong.. i didn't wot to start it or anything.. just after i got it runnin on my way home i opened it up, i guess tryin to see if it would clear anything up, and just to see how it went open throttle if it sputtered or anything.. but another update, checked for spark and got no spark in plugs 1 and 2.. so that changes things.. i think it may be crank sensor but not sure.. buddy is comin over tonight with a tech 2 but still any advice??

thanks for the help, brent