i need help, dieing problem after WOT nitrous run.
02-22-2004, 11:09 PM
#1
i need help, dieing problem after WOT nitrous run. this is going to be long but it has to be to explain where i am at.
same problem every time, truck runs fine all the time, i go out racing and after a nitrous pull it may die. it may not. after 2 pulls it dies almost for sure. sometimes it dies after a few minutes but often after the 2nd pull or so it dies right away. usualy start to run fine 10-40 minutes later
now to explain the dieing, it is like i am shuting the truck off and on, no sputtering, just an on off. if i am able ro rev it up it seems better but still doing it but at like 1500rpm is like i am on off on off on off, about as fast as it takes me to type that. it wont idle. it had this problem last year but went away when it got real cold out, now it is back. since then i have a new motor, pcm, injectors and still the same problem. it definately seems to be heat related. i have the right fuel presure and have been loging with efi live when it has happened before. everything looks good to me but i am no expert. when the motor was swaped so was the crank sensor and cam sensor. i have tried a diferent map sensor and evap noid or what ever that is, i tried pulling the nitrous and fuel lines to be sure there wasn't a stuck noid.
i have a couple of weak ideas, might try runing a hot wire to the injector harness, what about the coil harness? is there some common wire that could cause every cylinder to shut off at once?
anyone got any ideas? i have to get this thing fixed, racing season is about here.
same problem every time, truck runs fine all the time, i go out racing and after a nitrous pull it may die. it may not. after 2 pulls it dies almost for sure. sometimes it dies after a few minutes but often after the 2nd pull or so it dies right away. usualy start to run fine 10-40 minutes later
now to explain the dieing, it is like i am shuting the truck off and on, no sputtering, just an on off. if i am able ro rev it up it seems better but still doing it but at like 1500rpm is like i am on off on off on off, about as fast as it takes me to type that. it wont idle. it had this problem last year but went away when it got real cold out, now it is back. since then i have a new motor, pcm, injectors and still the same problem. it definately seems to be heat related. i have the right fuel presure and have been loging with efi live when it has happened before. everything looks good to me but i am no expert. when the motor was swaped so was the crank sensor and cam sensor. i have tried a diferent map sensor and evap noid or what ever that is, i tried pulling the nitrous and fuel lines to be sure there wasn't a stuck noid.
i have a couple of weak ideas, might try runing a hot wire to the injector harness, what about the coil harness? is there some common wire that could cause every cylinder to shut off at once?
anyone got any ideas? i have to get this thing fixed, racing season is about here.
02-22-2004, 11:22 PM
#2
i am going to get a scope and put it on one injector and coil so i can see which is loosing the signal, that might help to narrow it down some.
also one person mentioned a similar problem with an 03 grand am that they were spaying like mad, same year as i have, couldn't be some anti go fast crap GM might have programed in could it? exactly what sensors would get extra hot when spraying? front 02's seem to match wideband still, nothing else should see any change i wouldnt think, could the cold from the nitrous be affecting something?
also one person mentioned a similar problem with an 03 grand am that they were spaying like mad, same year as i have, couldn't be some anti go fast crap GM might have programed in could it? exactly what sensors would get extra hot when spraying? front 02's seem to match wideband still, nothing else should see any change i wouldnt think, could the cold from the nitrous be affecting something?
02-23-2004, 07:56 AM
#3
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There are abuse modes and also excessive knock
/ misfires might slide you down into low octane
table settings?
You should hook EFI back up and look as "misfire
history" (?) to see if there is excess of that on
track pulls. Maybe too late now? Do it next time
for sure, and leave it running during shutdown &
restart, see if the IAC is off from usual, or if it's
the usual IAC setting suddenly not being good
enough.
I sure do not like the IAC loop's robustness either.
I had a 3X crank-and-die the other day, just from
a little enthusiastic driving. I guess the best bet
is to give it some cool-down idle time before
you shut it off? ("Rode hard and put away wet").
/ misfires might slide you down into low octane
table settings?
You should hook EFI back up and look as "misfire
history" (?) to see if there is excess of that on
track pulls. Maybe too late now? Do it next time
for sure, and leave it running during shutdown &
restart, see if the IAC is off from usual, or if it's
the usual IAC setting suddenly not being good
enough.
I sure do not like the IAC loop's robustness either.
I had a 3X crank-and-die the other day, just from
a little enthusiastic driving. I guess the best bet
is to give it some cool-down idle time before
you shut it off? ("Rode hard and put away wet").
