TobiasRX

Everything wasn't joy with the car.

Yesterday it started and it warmed it up and only drive it like 50m to wash the car.

Today i took a test drive and it didnt turn out very well.

The idle was alittle bad at first and it smelled alittle ATF oil. After while that smell disappereed and the idle was good when the car was warm. I drove away, accelerating slowly, i loved hearing my turbos spool up. Then i wanted to give it some more throttle but then it just bumped, felt like a fuel cut but i only were around 7 psi. I wasnt even over 3k rpm. I thought the boost was building up unusually fast cause i didnt press the pedal much.

Don't know what it could be other than the ECU. I still have stock.

Yes i know i should get an ECU upgrade, and i have bought an AEM, but i'm gonna let the tuner put it in. I only wanted to try the car out and wasnt gonna try pushing it hard, only that i didnt even push it and it still bumped.

Hope u understand what i mean.

Sorry for the looooong post.

help would be useful.

thanks.

Snook

iTrader: (12)

we need more info just type every little detail it's okay if your post is long

Could it have been the 3k hesitation that happens at 2,800 rpms?

Did it just hesitate and backfire? Did it continue to do that as you accelerated or just for a second? Was the car bucking? Are you sure the car was at proper operaing temperature?

TobiasRX

No 3k hesitation, this was much much stronger, i expereinced 3k hesitation last year and it was slightly noticable. My brother was listening from a far and when it happened it got quiet for a split second and then a backfire that sounded like a shotgun.

I released the pedal when it happened so i don't know if it would continue, and i don't dare to try it again.


What is bucking?

And yes the car was at proper operating temperature.

Not sure what more you would like to know.

Snook

iTrader: (12)

bucking is when the car shakes back and forth

okay why don't you try letting it warm up and then while you are in place see if it will rev from 1-7k do it kind of slowly.

I would change the plugs for certain or at least see that yours are getting a blue spark
Could also be that the wires aren't secure or are on wrong but that's unlikely.

A bad O ring on an injector will make the car fall flat on it's face at a certain rpm depending on which injector it is that is leaking.

Can you hear any intake leaks in the engine bay when you rev a little?

The info that you left out is what you have messed with. If everything was working before what did you alter since then?

TobiasRX

oh sorry, i've put on a downpipe, pettit ecu, pettit power pulley and K&N filters.

No intake leaks or exhaust leaks whatsoever.

I had good spark on three plugs, on one the electrod(not sure what it's called in english) is further down but still made a spark. it's a trailing sparkplug.

I will see if i have acidentally messed with anything later.

TobiasRX

I've test driven it some more and i've noticed that when it's building boost it cuts off.

I've managed to get up to around 7 psi but i think it's because it's building so fast it doesnt have time cut it immediately.

Also i hear a vibrating sound coming from the pipe near the vacuum hose going into the intake, it's one of the two pipes were one is the airpump. Hope u understood the last part.

Snook

iTrader: (12)

i wish someone else would chime in I have no idea what you are talking about the vibrating noise

maybe you can point it out in this pic but I don't have an air pump

TobiasRX

u don't have that pipe on your car, and im not talking about the airpump.

I mean the pipe that should end right at the y'pipe coupling.

TobiasRX

anyone?

what could be wrong? it builds boost but immediately cuts off.


BTW Snook- i think you do have that pipe only i can't see it on the pic.

1 BAD 7

I'm basically having the same problem, although I can accellerate smoothly up to 4500 rpm then it cuts. Otherwise it is fine unless I go more than 1/4 throttle, then it bogs down regardless of RPM.

It seems to be related to my A/F ratio - it goes lean when it bogs, so I'm guessing the knock sensor may be cutting the fuel. It got better then longer I drove it - only have about 30 miles on the new motor.

Here's the thread I started:
https://www.rx7club.com/forum/showth...hreadid=171711

TobiasRX

1 Bad 7- did u try resetting your ecu?

I havent. How long can the ecu stay in limp home mode if i don't reset it?

1 BAD 7

erm...no i haven't. sometimes the most obvious things are the last ones you think of! i doubt that will make a difference, but i'll give it a whirl.

1 BAD 7

resetting the ecu didn't work. i think it's a solenoid issue from going non-sequential. you didn't do that, though, so...???

TobiasRX

i got my car to work after resetting the ecu

CantGoStraight

If you don't reset it then it will remain in limp mode. I would suggest pulling codes before reseting it next time as this may elude to your problem. Your mods with the Pettit ECU should get more than 7psi of boost without issues. When you do your boost test do it in 3rd gear....(do a search for boost test) as it will give you time to see when the primary spools, what it spools up to prior to transistion, and what your secondary boost/overall boost is to redline. When in limp mode the car will not take fuel very easily to 3k. it will fall flat on it's nose.

car hugger

iTrader: (1)

It could be the O2 sensor or one of the temp sensors.

I purchased a reprogrammed M2 ECU, and installed it with the same cut off/bogging once the car hit 0 on the boost/vac. If I accelerated slowly it seemed fine. I removed the ECU thinking it was faulty and reinstalled the stock one. I changed out the O2 sensor, water temp sensor, and located a loose ground wire on the UIM. Reinstalled the M2 ECU and no more problem.

Hope this helps.

dgeesaman

iTrader: (7)

I think the OP may not be reading the thread anymore.

car hugger

iTrader: (1)

Holy crap! I gotta remember to check the original post date. Doh!