GreenS-10

iTrader: (4)

Took Tams SS to the track this weekend and made 4 passes. On the last pass the performance was sub-par since she spun the tires pretty bad but as she was turning on the return road the car wanted to stall. When she got back to the pits it was obvious it wasn't running on all cylinders so I assumed it killed the plugs. After we got the car back to the house I pull all the plugs out. All the plugs look fine (all the electrodes) but it was a little rich and wet from fuel on some cylinders. It is running on 1-2-4 only. Cylinders 3-5-6-7-8 are cold to the touch when the motor is running. I replaced the crank sensor, cam sensor, map sensor, unplugged the maf, replaced the injectors, pulled the fuel rail off while fuel system was pressured up to see if any injectors where stuck open and tried another computer (out of a stock car so it would only fire up and then die since the parameters where different but could tell the problem was still there). I also threw a different tune in the current computer to try that. I have also checked the coil packs for spark with a spare plug and they seem to be fine. I looked at the reluctor wheel with a bore scope and it has all it's teeth. Crazy thing about this is the dead holes are cold to the the touch but when you unplug the injector the header tube starts to warm up. I am grasping at straws now and was wondering if anyone knows what it could be. I have checked the obvious grounds also with nothing obviously visually wrong

CBM Motorsports

iTrader: (2)

Have you tried unplugging all the injector and checking to make sure they have power? If you have a noid light, that would be the best way to check. Also, do you know what kind of fuel PSI you have at the rail?

GreenS-10

iTrader: (4)

I did check the injector pulse with a noid light and it seemed to be pulsing correctly. I didn't check all of them, only the couple of the dead holes.

NastyN8

iTrader: (1)

Switch the coil packs around and see if the problem follows. Any bench test done on them needs to be taken with a grain of salt. Unless it has a dead short or open it is pretty inaccurate. Only way to do it is with a good scan tool. Good luck! Let us know your findings.

GreenS-10

iTrader: (4)

Just in case anyone is reading this with the same issue the problem turned out to be a reluctor wheel that was separating due to failed rivets that hold the two halfs together.

.boB

iTrader: (1)

How did you find this out?

GreenS-10

iTrader: (4)

Well, while the motor was running rough it ended up pulling a valve out of the retainers and dropped the valve so the motor had to come out. While the motor was out I pulled the pan and noticed the gap between the reluctor wheel seemed larger than normal and when you squeezed it there was play between the two halfs. Changed it out to a billet wheel (and fixed the valve) and the problem went away.