Opinions: What wrong with GTP - NJFBOA - Home of New Jersey's Camaros and Firebirds

Dark_Knight7096 · 11-13-2007, 01:58 PM

Ok about a month and a half ago my GTP was idling REALLY rough and the drivers side exhaust smelled like straight gasoline, the passenger side pipe smelled a little more than normal but not like drivers side. So i Parked it for the day. Later that evening I tried taking it to my home till i could find out what's wrong with it, on the way to my house i threw a code that said, "Misfire Cyl 5" and "Cyl 5 injector circuit open", from there I took it to a lot to leave it parked for an extended period of time, my car stopped throwing the code and ran fine, until i stopped at a light then the RPMs would fluctuate between 1500 and 500 and most of the time die out unless i was giving it gas. It sat for a month, then i drove it and it was perfectly fine for a week, now the same thing is happening, running rough, drivers side exhaust smells like pure gasoline, and car stalling out at stops, no codes have thrown yet though. Last time it happened I purchased a new injector put never got around to putting it in because the problem went away for a while. Now i'm not sure if a single injector would be causing all these problems. What do you guys think? Does this sound like it is all being caused by the 1 bad injector or is this something else?

WildBillyT · 11-13-2007, 02:09 PM

Well, GTP's aren't true dual exhaust so that kind of kills that part of the diagnosis.

1.) Have you worked on the electrical system recently?
2.) Have you done the fuel pump hotwire/fuel pump resistor bypass?
3.) What components are in your ignition system? No aftermarket coil packs I hope.

Anyway, for starters I'd check your fuel injector harness around cylinder 5. See if the electrical connection is torn, loose, or damaged.

Dark_Knight7096 · 11-13-2007, 02:17 PM

ignition stystem is stock, last mod i made to the car was a pulley and pcm swap back in june.

Full mod list:
lowering springs
stiffer shocks
(nothing to do with problem)

Thrasher CAI
R/T downpipe w/cat
SLP cat-back
(Nothing to do with problem)

3.6" MPS
(probably nothing to do with)

ZZP V1.0 PCM
(Swapped out 5 months before problem started)

PS gonna sound like a REALLY stupid noob ? but which cyl is #5? lol

WildBillyT · 11-13-2007, 03:10 PM

Quote:

Originally Posted by Dark_Knight7096

ignition stystem is stock, last mod i made to the car was a pulley and pcm swap back in june.

Full mod list:
lowering springs
stiffer shocks
(nothing to do with problem)

Thrasher CAI
R/T downpipe w/cat
SLP cat-back
(Nothing to do with problem)

3.6" MPS
(probably nothing to do with)

ZZP V1.0 PCM
(Swapped out 5 months before problem started)

PS gonna sound like a REALLY stupid noob ? but which cyl is #5? lol

Thanks.

Not a stupid noob question, but a simple answer. Find the #5 on your coil packs and trace the wire to the cylinder. That will be it.

Dark_Knight7096 · 11-13-2007, 03:35 PM

Quote:

Originally Posted by WildBillyT

Thanks.

Not a stupid noob question, but a simple answer. Find the #5 on your coil packs and trace the wire to the cylinder. That will be it.

duh, i'm an idiot
lol

GP99GT · 11-13-2007, 05:33 PM

as billy said, GP's dont have a true dual system so the same exhaust is coming out both tailpipes. if the #5 injector is either dumping fuel in all the time or not dumping any fuel at all, thatll cause a rough idle...id suspect dumping extra fuel though, that would throw off your O2 sensor and make it run even worse

Dark_Knight7096 · 11-13-2007, 06:02 PM

checked the top of the injector looks just like the other ones, and i knew it would be causing the rough idle but i dont think just the one injector would cause the car to stall out would it?

WildBillyT · 11-13-2007, 06:38 PM

Quote:

Originally Posted by Dark_Knight7096

checked the top of the injector looks just like the other ones, and i knew it would be causing the rough idle but i dont think just the one injector would cause the car to stall out would it?

Yes, it could.

Go ahead and remove the injector and have a look at it. Pull the spark plug from that cyl as well and let us know what it looks like.

Dark_Knight7096 · 11-13-2007, 06:50 PM

Quote:

Originally Posted by WildBillyT

Yes, it could.

Go ahead and remove the injector and have a look at it. Pull the spark plug from that cyl as well and let us know what it looks like.

well i have a complete set of new sparkplugs, i was looking to swap them out anway so i'll probly pull them all and put new ones in. ugh i don't have a free weekend for another 2 weeks

Tru2Chevy · 11-13-2007, 06:54 PM

Quote:

Originally Posted by Dark_Knight7096

well i have a complete set of new sparkplugs, i was looking to swap them out anway so i'll probly pull them all and put new ones in. ugh i don't have a free weekend for another 2 weeks

Make sure you keep the plugs in order when you pull them out (you could just number the boxes for your new ones and swap them one at a time, putting the old one in the appropriately number box) so you can inspect them all when you are done. That should help clue you in on what is or isn't happening in each cylinder.

- Justin

WildBillyT · 11-13-2007, 07:24 PM

Quote:

Originally Posted by Dark_Knight7096

well i have a complete set of new sparkplugs, i was looking to swap them out anway so i'll probly pull them all and put new ones in. ugh i don't have a free weekend for another 2 weeks

Which ones are you putting in? Autolite 104's?