RB25 Engine Shuts off at WOT at higher rpms

[FlyinFINN]

It's an S2 RB25, I have a good working TPS (just put it in, old one was acting up, Q45 TB), brk6e plugs gapped at .8mm (brand new), ISIS Intake Manifold, Open exhaust, running 7psi off wastegate, stock ecu, FMIC.

This engine has just been put in the car and finally got it running good, feels nice and strong, but when I go WOT and get in the higher rpms the engine kinda shuts off and when I hit the gas all I hear is the turbo spool and then wait a few seconds and BRR it turns back on.

I thought fuel cut? speed cut (I dont have speed sensor hooked up, this is an Rx7) but maybe it thinks im going 113mph? and a boost leak that only opens at the higher boost times?

Anyone have any incite on this, car runs pretty good otherwise. Thanks.
Modified by FlyinFINN at 11:23 AM 9/3/2009

[FlyinFINN]

Any ideas even?

[crazyandevil05]

just after getting my car (~3 yrs) after any hard pull in about 3rd gear or more at high RPM, if i put in in neutral, as the rpm were going down, it didnt go back to idle, just stall. swapped out for an optima yellow top battery and all was well. then after install of an amp and sub with new stereo and speakers, problem kinda started back up, so checked the alternator, turns out the chassis plug wasnt all the way in (the ones that tells the alt how much voltage the batt has, so it controlls how much the alt. is on- totally guessing on that part as i havent done more research since then) so maybe check charging system? but honestly, that doesnt sound like the problem. does it go lean/rich right before? maybe stalling from either of those? at what RPM does it happen? any boost gauge?

[crazyandevil05]

oh,a nd another poss unrelated question, there was a guy asking around about "knock off" greddy intake manifolds. Not that i'm knocking you having ones, but how did that work out for you? i heard godspeed, who was selling them, backed them up with fitment/problem issues pretty well (not a qoute, just 3rd hand info), just wondered about the guys who didnt have $900 burning a hole in their pocket. thanks. see ya tomorrow morning, i'll be up at ~10 am, since i'm off work from back surgery (yay, day 24, only 40ish more to go! but yay DOD for still paying me!) and by brake job, i mean i have my wife loosen the lugnuts, since i cant do more than "light lifting", then set up the jack so she can raise the car up....well, you get the idea, isnt it sweet to have a wife that help you work on your girl-friend, haha. ok, now off to bed, pain meds kickin in so i can sleep.

[FlyinFINN]

Which wire are you talking about on the alt? The one that goes to the check light or the one that goes to the battery (small one)? I dont think it's the alt since I just wired it up recently and the car had alt problems before. As for the Freddy Manifold it fit great and all I had to do was port out the water ports a bit to match the motor and it seals great and no water leaks.

But yea, this engine shutting of thing is kinda a pain the a**.

[FlyinFINN]

Bump, anyone have any insight?

[blues14]

try a shorter gap on your spark plugs......maybe boost just blowing them out?? just an idea.

[FlyinFINN]

I'm running stock psi at stock plug gap, what do you mean boost blowing them out?

[imotion s14]

air is an insulator.

[FlyinFINN]

Oh you mean blowing out the ignition spark? I highly doubt it.

My problem was the TPS needed adjusting, I had it too far out of adjustment and once I would hit full thrtl it would go past the reading of the potentiameter and screw up. Idle volts on white wire of tps should be 0-.5volts and WOT should be 4.5-5volts. Just future reference for anyone that gets this problem.