LS6427

iTrader: (2)

Try it this time by taking just the pos wire off and tapping it against the pos battery terminal port.

04_turboed_neon

iTrader: (2)

After resetting the PCM it still misses alittle on every cylinder, its very random misfire. This was kinda wierd, the Map sensor voltage was at or above 2v at idle. Should it be there? Also, when i pulled the map sensor, there was a part of the rubber grommet that had a little tear, at the bottom, but had actually cut through the whole rubber grommet. Could taht be it? Replace grommet, or whole sensor?

I do have boltons, and cam, FYI.

Devin

04_turboed_neon

iTrader: (2)

Well its not the MAP sensor. I replaced it, reset comp, and still miss firing everywhere. WTF!!!

Devin

1987firechicken

Out of curiosity what kind of plugs did you use when you changed them? What heat range are they?

04_turboed_neon

iTrader: (2)

NGks at stock heat range. Tr5's

Devin

LS6427

iTrader: (2)

Damn!!!!! Maybe pull them to make sure none are cracked. Did you make sure the gaps were correct and not totally messed up?

04_turboed_neon

iTrader: (2)

I gapped them all at factory specs(60) before installing them, and none are damaged, i've already pulled them out and inspected them.

Devin

LS6427

iTrader: (2)

Take the radiator cap off, drive your car away and drive a new car under it, replace cap.

LS6427

iTrader: (2)

Only other thing is an electrical short somewhere in the ignition harness. Maybe take it all the way off the car and check it out.

04_turboed_neon

iTrader: (2)

Trust me, if that was an option, she'd be gone right now. lol damn random misfires.

Aight, i'll see what i can do.

Devin

04_turboed_neon

iTrader: (2)

Could it might be a Cam sensor, or crank sensor? I know most people say that when a crank sensor fails it usually wont crank, but could it be failing?

Devin

LS6427

iTrader: (2)

THe Crank Shaft Position sensor can do exactly that...hard starts, stalls suddenly, and bucks and runs like hell.

And yes, the CSP sensor can fail over time, while its failing, sometimes it works great and sometimes you get those symptoms I listed above.

You can change it out in 5 minutes after you lift the car up on ramps or a lift. Drop the starter and its right there.

You can get one at Advance Auto or PepBoys to try, if it doesn't help you can clean it up and bring it back for a refund.

Also, if it is a bad CSP sensor, it WILL NOT neccassarily give you an SES light and a cheap scanner like they have at Advance or PepBoys might not show the code. When mine went, it took the expensive OBDII scanner that the dealerships use to show it.

04_turboed_neon

iTrader: (2)

welp its not the crank sensor. IDk anymore, im gonna take it my tuner and let him mess with it.

Devin

billymz28

just because the plugs are new it dont mean they cant be cracked. I work at a part store and the plugs are thrown around in baskets and in shiiping when stocking.it happens more than you might think. I also had a friend who had the same problem with a misfire and it just randomly went away still dont know why.

Sharpe

iTrader: (7)

You meant the front O2's, right? The rear ones mean nothing. The front ones can cause the car to miss, though mine showed no misses when I switched mine from right to left bank on accident. I went out and got new Bosch 13111's so I wouldn't have to run the extensions, and put them on the right side (duh). Fixed my random misses.

sic2001

iTrader: (5)

Did you delete the EGR (if you have it)and Air system,unplug pump get rid of all those vaccume lines behind the intake? I had the same problem and it went away only when I did that.

CayenneRedV6

iTrader: (8)

I had a miss at high rpm's I couldn't track down after I installed my headers. I spent hours trying to find what was causing it. It turned out to be the gap on the plugs. I had gaped them to the factory .60 but after taking them out and re-gaping them to .35 NO miss fire. Try re-gaping them to .35 and see if that helps.