Occasionally headbutting the steering wheel
 

Hello,

93 classic WRX STi

This has only happened twice in the last month, but when I went to boost my car earlier (it was warm) I put my foot down, it started to spool (4.5k-5.5k RPM), but then it kicks right back, and I nearly headbutted the steering wheel :brickwall

As I say, its only happened twice, and once I come off the throttle and back on, everything seems fine. Seems the car has spat out what it needed to, and then off she goes as normal.

Would that be anything to do with the front mount, or walbro fuel pump/larger injectors? It was tuned earlier this year, and apparently tuned to run very rich for Santa Pod.

The car gets about 130 miles for £55 of Shell V-Power. Is that silly?! :wonder:

I'd try putting the seat a bit further back, and were a harness :D Seriously i think you should get a mapper to look at it as i can't see anyone tuning a car to run very rich.

Mike

Crash helmet prehaps to protect your head

Thats boost cut/fuel cut, your boost is spiking so the ECU says "Woah there Horsey!" and stops something bad happening.
You want to look at your boost control system, and what is fitted manual or electronic, if its manual it needs adjusting, if its electronic then may be a leak.

Did you have yours mapped before or after the FMIC was fitted??

Its got a EsL re-mapped ecu and was mapped after the FMIC I believe. I bought it very recently.

Its deffo boost cut/fuel cut. I`d check with who mapped it to double check.

But worth doing a CEL test to see what codes are being flashed up as to be the cause.

Have you changed any parts recently??

Could be one of a couple of things, overboosting would be my first choice, does it do it in every gear or just 3/4/5?
Does it do it on part throttle or just on wot?

Tony:)

Come to think of it, both times I was holding 2nd on part throttle and then when I went full throttle it did it.

Certainly sounds like fuel cut, do you have a boost guage fitted? Quite normal for your car to boost slightly higher than normal in cold weather. If your fuel cut has been set close to your normal boost threshold, the colder weather may just have made it reach it.

You don't produce full boost in 2nd so that rules out fuel cut, you could check the boost solenoid, but had something similar with my spec c and it turned out to be a sensor issue (3 actually that were replaced), but the main culprit was the cam position sensor.

Tony:)

A CEL test? Is this a diagnostics or something? Zen performance in Wellingborough is my closest option I believe.

I've changed no parts at all under the hood.

I'll get some help from my mates on checking these.

Cheers Tony.

Steve.

My Impreza...

Takes way too long turning over (seems to hiccup throughout)
Strong smell of fuel when it finally starts (although It hasn't ever failed to start)
Idle seems fine
Possible boost/fuel cut as above posts
I believe it runs way to rich (120-130 miles on £60 of V-Power this week) :wonder: (someone tell me if I am wrong)

Just called Zen, a very helpful chap said to take it along soon for a check. His first thoughts... some faults could be due to a faulty Lambda sensor, and might also need a re-map. I'll post up the outcome once I've paid Zen a visit.

Cheers.

For the fuel cut issue have you tried cleaning the boost solenoid?

http://www.scoobypedia.co.uk/index.p...ontrolSolenoid

This is a copy paste of the mods on the STi. If I need to buy a new Lambda/Oxygen sensor, could someone point me in the direction of which to buy?

ENGINE AND GEARBOX
342.2bhp (with print out)
Autobhann 88 FMIC
TDo5 16G turbo
De cat exhaust
Stainless exhaust system
Hks headers
Hks bov
Blitz air filter
Sti forged piston
Sti gearbox
EsL re-mapped ecu
Exedy padle clutch
440 injectors
new coil packs
walbro 255 fuel pump

Cheers.

Resurecting an old thread here to try help find this problem.

Since this thread, the cable leading to the O2 sensor melted on the exhaust and shorted the car out.

The car now idles high, has a hiss from around the induction kit area, and has boost cut at 4.5-5k rpm EVERYTIME now

Replaced so far:
O2 sensor
Cables leading from the o2 sensor
Fuse (that primes the fuel pump? Green one in the main relay box under the bonnet)
Boost solenoid
Cleaned ICV

Error codes have changed somewhat, but the current ones are 24, 44, 12 and 32.

Tried an ECU reset after changing the boost solenoid last night.

What should I test/check next? MAF sensor? CAM posistion sensor? ECU?