I'm tryin to tune the car using the PF, but under load it hesitates or misfires at about 7-9psi(usually around 3k rpm). Now when I log it shows AFR to be around 11.1-11.8 on anything less than 70% throttle. But anthing above 70% its in the 9's or 10's. The more throttle the richer it goes. But I have only been able to hit like 9psi before the misfire happens. So should I continue to lean it out and hope that takes care of it or should I be looking for other problems that may be causing the miss. The car idles and runs great if its not under load.

My car was stuttering at like 4k, changed spark plugs and problem solved.

I'm going to pull them out tomorrow after work. I had them out a few weeks ago and they looked fine, but if the plugs look good I'll check the wires and coiles.

Yea, sounds like you are blowing spark. If the PF is richening up the fuel mixture as you create more boost with more throttle, it is working correctly.

Throw in a set of NGK BKR7E's and then go back out and log some runs. Try to get a nice constant AFR curve of about 11.2-11.5 across the board and you will be happy with the results. You should be able to take off 10-15% from Hahns base map, but just do a little at a time to play it safe.

I already have the BKR7Es and already have 15% taken out of the base map. But when the car cools down I'll start figuring out what is goin on with the spark. I got my codes read and I got two for the coil, so its probably the coil, wires, or plugs. I'll update in a little while.

Okay, I checked the plugs and they seemed to be ok(Black on the base ring indicating a rich A/F.)

So I used a timing light to see if spark was goin through and it was. However, the light wasn't hitting as fast on cylinders 3&4 as it was on 1&2. So I switched the wires and that didn't change it. So I reved it and the spark cut out on 4(didn't test 3 but I'm sure its the same). So anyone have any clue about this?

Probably need a new coil. Do you have another working coil available to swap in and test?

Man I hope not, I just got the MSD last year I believe. But thats what I was thinking at first, then I found it odd that cylinders 3&4 where being wierd and 1&2 where fine. Because the coils run 1&4 on one and 2&3 on the other, which doesn't make sense for 3&4 to be bad like that. But I'm going to pick up new plugs tomorrow and see if it changes, if not then I'll put my stock coil in(hopefully its good lol).

The MSD coil is an inferior unit to the stock one. It puts out the same amount of voltage but doesn't have close to the longevity that the stock piece has.

As long as the stocker was working when you took it off, put it back and see if you get better results.

So the MSD isn't an upgrade?
Well I changed plugs and coil and problem gone. I'm pretty sure it was faulty plugs, becuase the timing light was the same with both coils.

Originally posted by bagged420a
So the MSD isn't an upgrade?

Nope. Not at all.

IIRC the coil that's an upgrade is the Screamin Demon

Ronin is correct. The MSD is a stock replacement, meaning it puts out the same amount of voltage as a stock coil. The problem is, it does not have the longevity of the stock unit and will not last nearly as long.

If you want an aftermarket coil that is actually an upgrade, go for either the Screamin Demon which is sold by Howell Automotive, or the 034 unit which can be found at the link below:

http://www.034motorsport.com/shopping_cart.php?sort=2a

If you are handy, you could also rig up the good old dual Accel unit. Do some searching on the forum and you will be able to find some threads on it.