rod442

Ok, I had a bad lifter. decided to go ahead and put on some 6.0l heads while they were off. installed lifters, stock rockers, the heads with my rev springs, and comp pushrods, etc in it. got everything on, intake torqued down, fired her up a few times, but didn't let it run by pulling the injector fuses. that way we could get a bit more oil to the top end of the motor.

fuses back in, started up fine, my buddy asked if I had oil pressure; and I shut it off and said "what? didn't hear you." then it wouldn't start. thought we had just fouled the plugs, since it runs rich untill it learns with the 42#ers in there.

messed around with stuff, then decided to check for spark, NONE! was late, gave up for the night. next morning, started right up, purres like a kitten. for a whole 60 seconds. Then died like I shut the key off. No spark again.

went to the track to race my buddies formula, next morning; same thing. started up, kinda rough though. seemed like it was running on 5-6 cylinders. could keep it running, and even was able to get it to restart 8-9 times while it stalled when I let off the gas. then no start, no spark.

I can say for sure that its not the cam sensor, that doesn't control spark. its not the relay, or any fuses in the fuse block. not coil packs unplugged, and they have voltage with the key on at the pink wire. its not the crank sensor, cause it reads rpm when cranking. its not the pcm, cause we can get all the readings from autotap. AND it sets NO CODES. or is it the computer? a knowledgeable member of this board says pcm should be fine.

So what is it? ONLY thing I can think of is a missed ground on the back of the drivers head. BUT answer this: How many seperate wires are there connected on how many lugs that go back there? There is 1 lug with 2 wires on it currently bolted on the back of the head. Assuming we missed one, does anyone have a picture of what wiring harness it leads to? we can not feel any more wires back there.

Please help, getting desperate. Car has been down all summer with what I thought was a bottom end noise, then decided it was a lifter. now after it is assembled, I would like to make the 2 track days left around here.

btw, car is a 2000 formula 6 speed with an incon kit on it.

Mustang Hat'r 2

iTrader: (24)

Theres 2 wires on one lug then another wire on a different lug. There both in the main harness its right back there you might have pinched it in the intake or something. I would take the intake off so you can see a little better and find it.

y2khawk

iTrader: (5)

see, what did i tell you?? :p

rod442

that is what you did tell me , but Al said he couldn't see or feel it back there. and was wondering how to find it. yuck, taking the intake off

1999_SS_M6

I don't have any pics for you, but there are 3 ground wires on the back of the driver side head. There are 2 bolted together, and one separate. I usually combine the 3 onto one bolt for ease and servicablitiy. Good luck sorting it out.. let us know.

SilverGhost

iTrader: (53)

I have all three gounds on the one bolt to keep track of them as well.

And that sure as hell could be your cam sensor, it has everything to do with spark. But if the car is not throwing any codes, then I would assume no sensor problems, the car would tell you if it lost signal from the cam sensor.

All three of those grounds come from the same place basically in the harness, right behind the head where they are grounded, I agree that its very possible it got trapped under the intake and that's why you can't find it. I would run your hand around back there across the area where the intake meets the valley cover and feel for any random wires coming from it going into the harness if you don't feel like pulling the intake right away.

kevredz

iTrader: (2)

Do you think the 42lb injectors have anything to do with it? I heard that if you upgrade injectors, the computer needs tuning and will not "learn" the new injectors. Just a thought.

rod442

nah, bigger injectors shouldn't cause it to not spark. they will however DUMP gas in right now until the computer learns a bit. Even with the reprogramming. had to take plugs out 2X when it went to "no spark mode "; just to dry them off. they have been in the car with a piggyback computer to run them since 5500 miles, car now has 34000 on it. also the rest of the tuning was done with ls1edit this spring.

the guy helping me out, said for sure that there is only 1 lug on the bolt for ground; the one with 2 wires. but he can NOT feel the other one. wonder where it is? I am 90 miles away right now from the car, I wont have time to look at it myself till Sat.