Are you the one with the white supra that was next to me on 275 to the 56 exit?

 

yeah that was me on 275, my wife was half asleep telling me ''you better not try to race''. plus I had my kid in the back seat. I tried to race quitely flooring it in 5th gear. it even misfired then.

just today while leaving work, the supra wouldn't move forward, the misfiring was so bad for about 2 seconds then finally went back to normal.

I turned around and scanned the obd2 swapped ecu, no misfire codes active or history.

I did have the usual trac disabled code and a P1162 exhaust bypass valve circuit malfunction, which I'm gonna look into. it may just be the vacume t mod making 15psi.

I am gonna re gap my plugs tommorrow. sorry for such a long post. this sucks.

oh yeah. I do have the denso ik22 iridium plugs (1 heat range cooler than stock). I am going to regap them, check connectors on coils, clean out the aem air filter, and see how that goes.

 

Do you have an boost cut controller on the car ? You may be hitting boost cut @ 15psi which explains the "miss-fire". Do you live in the New Tampa Area? If so I don't mind helping you check over the car. I live off of 54 where the new Ferman Dealership is at.

 

I do have the greddy bcc installed and operating (spike at 18-20 psi) with no cut.

to add to the mayhem. last night found out via wideband that car not entering closed loop, I can tune my idle with my apexi neo, (usually not possible while in closed loop). 3 month old oem o2 sensor. it may or may not be related to the high rpm misfires.
I was told to check my coolant temp sensor. well see
I've still got to check into the basics 1st.

as far as new tampa goes. I just temporarily moved last night back to tampa with family, (in process of trying to sell old and find new home) so I've got very limited time, but I appreciate the offer to help diagnose this. I'm gonna try the basics 1st, it may be something stupid.

ill repost in a few days, I got too much goin on, now and days. life is too busy.

sometimes I wish I was omish (with a supra)

 

I would make sure you check the connectors to the coil packs. Now it's misfiring at more then just high RPMS.

Use a resistor to get rid of the TRAC code. mkiv.com I believe has an article on it.

 

It wont be cats or any stuff like that. I would see if you have a MAF leak if you still have one. All the intercooler piping, TB gaskets/IM gaskets could be leaking. Also, you should pop out the plugs after a few days of driving them so far, and take some pictures. Post them up and maybe some of us here can be of more assistance. I have no experience with the IK plugs, only NGK 6097 and 3330's. Is the IK22 or whatever a reccomended BPU plug on SF or on TSF? My car would break up up top as well. I had a problem with my BCC, however it would not in neutral, or at slow speed. Mostly second gear with lots of wheelspin!

good luck!
Mark

 

Awesome. I think its finally fixed. Quick Recap.

The car would misfire when you floor it in neutral, sometimes while driving at high rpms or downshifting.

It turned out that there was a cold joint in the odometer circuit board. I saw a writeup on supraforums.com, other people have noticed this also.
Something about the speed signal that runs through it, the soldering point for it goes bad. All I did is dis-assemble the odometer and touch up each soldering point. Has worked fine ever since (which has only been 12 hrs btw).

Hopefully it doesnt come back.

I did also check all connectors, plug gap, air filter cleaning, and etc. in addition but never got better untill I took apart the odometer.

Thanks All

 

Cold joints have been a number of problems on these cars...