Strange hesitation at 6500 rpms???
 

While racing this morning in a 3rd-4th gear run when I hit 6500 rpms the car hesitated and then continued to accelerate (in 3rd) - the same happened in 4th at the same rpm. I saw a little smoke out the exhaust right when it happened but the cars runs great. My car wasn't exactly warmed up all the way (the therm. needle was still towards cold but almost to where it should be) and I'm running 20W-50 oil and it was cold this morning. Do you guys think that's what caused the stumbling or ignition breakup. It's never happened before. It felt almost like a fuel cut off - but I have the PFC though.

Mine does that too ... it cuts off at around 6-6500 rpm
happened to me 3 or 4 time in 3rd gear at 10 psi but then again i don't have an ecu yet.... it runs fine at 7 psi tho.. so right now i'm refraining to boot it until I get an ecu...:o

Mine does that too, and i DO have a remapped ECU. I don't know what the deal is, but i can usually tune it out with my foot. Only happens at 10+ psi.
~Tom

Try checking those sparkplugs and wires. That could be the problem.

You may want to check that out. If you were driving and saw smoke out of your exhaust then it wasnt just a little bit. I get what seems to be a fuel cut around the same rpm as you but only in 5th gear.

It's not my plugs or wires. I think there's a mip missing in my fuel map.
~Tom

You can still experience a fuel cut with the Power FC, it happened to me a few times. You might want to recheck your spark plugs again and replace your fuel filter. If that doesn't work you can adjust it on the Power FC to eliminate the fuel cut.

I just emailed Dave at KDR about my problem and he said that they are having problems with the PFC being programmed with too much timing and is detonating engines!!!!! There's a good chance that that hesitation was the engine detonating but the knock sensor picked it up both times. He said he's able to fix it with simple programming but that is scary. My plugs, wires, and fuel filter is all new (within 3K miles) so that's not it.

Im having the same problem.. only at 10+ psi.

BACK FROM THE DEAD!

Mine was fuel cut :)

Fuel cut at 10psi ?!?!?!?!?!?:?:

check your boost patterns it could be your turbos not switching over

mine kinda does it to but it happens during transistion. like i get full boost untill like 4500 then it kinda lags for two or three seconds..like its lookin for the other turbo..then bam..im on full boost again..i dont get it...:confused: hope i dont need new turbos...:eek:

riptor, your problem sounds more like a sticky turbo control solenoid or actuator for the turbo control. At 4500 rpm, the second turbo should be up to speed, the door that shuts off the secodary turbo from main flow opens, but the second turbo isn't getting enough exhaust flow to support the pressure. Once the turbo control solenoid opens at 4500 rpm, it sends exhaust directly to the secod turbo to keep it at full speed. If the turbo control solenoid or actuator stick closed for a few seconds at transition, the turbos fall on their face when the two flow streams are combined, then come on strong when it opens.

The solenoid is part of the rats nest under the UIM. The actuator is the big can like thing on the bottom of thurbos, seen easily from under the car on the passenger side.

at 6700-7000 rpm's i get like crazy ass back fire (poping noises). i got a PFC at 12psi in 2ndary. pattern i think is 10-10-12 seens to me alot of FD's have this problem. i heard it was spark plugs and spark plug wires

spurvo that sounds like whats happening with my car :(

Click here for an mpeg of it happening on the dyno (it occurs at around the 6 second mark).

A/F ratio from the dyno was 10.1 at the point it occured, then spiked to 12.1 and settled

Ignore the oil smoke on ramp down... turbo seals are real bad. Replacing with rebuilt twins this weekend and going non-sequential.. perhaps that will help :D