My car has most the bolt ons and I just got done hooking up my TNT kit. I decided to spry a 100 shot to start with. The first time I sprayed, I had the window switch set at 3500 rpm. The bottle came on and by 3700-3800 rpm the car felt like it was shuddering, almost as if I had a cyl that wasn't firing. I let off and waited to borrow a buddies A-tap.

Went out with A-tap and tried it again. 3500 rpm on and shuddering real quick (up to 4200 rpm). Got a flashing SES light and a DTC. By the time I pulled over the DTC and flashing SES were gone. I figured it was a plug misfiring and I would change the plugs. I reviewed the log and noticed I was running rich (.94-.95 on the O2's).. I decided to make one more pull at a higher RPM to see if that would help.

Rolled on the bottle at 4500rpm in third and it left like a rocket with no problems so I short shifted in to fourth and took her up to 115-120. Let off as I felt if kind of surging forward and backward like it was losing power for a second. Went to stick it in 5th and the clutch was stuck to the floor.

I changed the plugs to eliminate that option and they were very black for 2k miles. A-tap showed I was running around with -15% on L-trimms and was at .935 at WOT NA.. Went for a ride last night and started the pull in third again @ 3500 rpm. Car shuddered a little and I let off. Brought it up to 4k rpm and went, no shuddering just pulling like mad. It was somewhat hard in to fourth but once in it was pulling good as well but it seemed the RPM's were coming up and holding at 5500rpm before the cars speed was there. Pedal was again on the floor and it was next to impossible to get it in 5th or 6th. Coasted a little way down to 55mpg and it went in to gear again. Pedal still felt soft though.

The car has the original clutch with 65k miles on it. Is the shuddering feeling a slipping clutch?

 

You could try a good bleed but if your using nitrous on the stock clutch it is probably time for a new one. Also make sure none of your hydralic lines are running to close to any exhaust compone which could cause the fluid to bleed. The shuddering I'm not so sure about especially cause its only at the single rpm point but the pedal sticking to the floor and it being hard to get in gear would normally sound like a hydralic issue but if you are on your stocker clutch it may be time to replace the entire setup.

 

Anyone else?

 

I would agree w/Mike K, your pedal is goin' to the floor your gonna need clutch hyraulics mininumn.
65k oe clutch might as well replace it w/ the trans is out.
A hard shutter can fool PCM into thinking there is a misfire.
Even a real rough road can also.
You should redo the entire clutch set-up, you'll be happy you did.'specially sprayn'