subaru1994

iTrader: (2)

hi guys ive recently purchased a 1994 subaru 2.0 turbo it has the following modifications, full cat back exhaust, tdo5 turbo, sti gearbox, z4 ecu with stage 3 remap, k&n air filter

the problem is every time i take the car to 4000 rpm or more it will missfire like hell, the rev counter will drop to zero, it will run like **** until i let go fully off the throttle and it will sort itself out but the idle will be up and down up and down and will not sort itself until i have switched the car off, however if i stay below 3500rpm it will not do this,

i took it to extremes subarus and he diagnosed it to be boost control solenoid and lamba sensor, spanked me £360.00 and it still has the problem, i have further changed crankshaft sensor camshaft sensor, knock sensor, coil packs, spark plugs, i just feel like im being thrown from pillar to post

does anyone no what can cause this could it be maf

sonic93

iTrader: (16)

they told u the prob was the lamba sensor and boost solenoid and u still have the prob take it back to them u spen t alot of money there withyour car not running correctly. i have a lamba and a solenoid could of had mine for 50 but u prob don t wanna know that now lol. have u checked plug gaps should be 6.5,coil packs for slight hair line cracks under the rubbers.did it run fine when u brought it? have u tried the original ecu on it ?

sonic93

iTrader: (16)

could be the maf but extreme scoobys should of checked this for u mate i got 1 here to if u need parts im breaking my 1993 wrx

scooby800

iTrader: (1)

could be fuel pump going weak and running out at high revs do you have a fuel pressure gage?

KLR16V

iTrader: (2)

what boost is it going up to ? You can not run above 1 bar on a normal ecu as fuel cut is set to this roughly, normal boost is 0.8 bar , if modded ecu with piggyback then max boost is about 1.1bar with fuel cut raised to 1.2bar as the standard map will not go beyond this , if the map sensor has been changed for a later one and re-scalled then you can go further . Does sound like fuel there is a big difference between this and a missfire .

Mark

myblackwrx

iTrader: (1)

Find out what a 'stage 3' remap is as the early cars cannot be remapped without the addition of a chip or daughter board.
This also requires a resistor (marked as J1) on the ecu board to be cut/removed if it is there you can resolder it to let the OE ecu run the car.

Glowplug

iTrader: (8)

Well done, welcome to SNet.

Someone is talking bo11ox there!
It will be, a] a Z4 b] a Z4 with a ESL board or c] a Z4 with a chip. Pull back the passenger side carpet, remove the kick plate to uncover the ECU. Then remove the ECU and open it up. Take a picture and post it on here. We can then see what you have.

Have you got a CEL on on the dash?
Does the CEL come on at acc position with the rest of the check lights??


As already said, take it back to them and get them to sort the real issues as what they did, did not sort the problems.

Why did you change these items??
Did your diagnostic check flash these faults??


You need to do a full ECU reset and log any faults. Then post back your findings for further advice.

Here or here for how to reset and read fault codes.

P1Drifter

iTrader: (7)

speedo work ?

musso2010

Someone i knew had a similer problem. After spending a fortune on MAF's, coilpacks and plugs it turned out to be a burnt out valve. Maybe get a compression check done!

subaru1994

iTrader: (2)

thankyou for the replies and suggestions, i will undo the ecu tomorrow and take a picture as its a bit late now, i noticed that the o2 sensor on top next to the turbo has been disconnected, i have been told that this is the fueling 1, has it been disconnected because it has been mapped or does it still need to be disconnected.

no the speedo stays the same, when on boost at 4000-4500rpm it will missfire and the check engine will flash, it will sort itself out after a min or 2, but it won't idle properly which lead me to belive a dodgy maf, but can't understand why the rev counter will go totally.

extreme scoobies plugged the two green wires together and it selfchecked and the boost solenoid wasnt clicking, so he said that wasn't working at all, then he done a check with his computer and said the bottom lambda sensor wasn't working at all so it need replacing, he said the boost control solenoid would be causing my problem,

and then other people told me it was crank and cam sensor coil packs sparkplugs and so on, after changing them all it is still doing it.

i will do another ecu reset and post the faults that it is showing

subaru1994

iTrader: (2)

how much did you want for the maf my number is 07894732698

Glowplug

iTrader: (8)

OK we will need a pic of the top of the case and a pic of the inside too.

MY94 only has 1 lambda sensor, usually located in the drivers side exhaust header. If you slide under the front o/s you should see it clearly enough. The other sensor in the down pipe is the cat on fire (exhaust gas temp sensor), if you have a decat exhaust then this can be removed without issue.

A Z4 ECU cannot be re-mapped 'per-se', it would need a daughter board or a generic chip fitting.


So you are saying that the speedo is NOT working. That alone will put the car into limp mode and prevent you revving above 4500rpm. It indicates that the speedo cable has become disconnected or snapped and needs to be investigated and solved.


Subarus are not well known for 'sorting themselves out'


Slow down there mate. You have other issues to solve before replacing the MAF.

It would of been worth trying to clean the BCS before stinging you for a new unit

He should be well aware that your MY only has one Lambda sensor.

Your OP never sounded like a faulty BCS. I would be back to xtreme asap for an explanation.


VSS Code 33 will be one.

subaru1994

iTrader: (2)

would it help if i get a passenger to take a video and post it to show you exactly what happens, i don't think im explaining it very well,

ive tried ringing extereme subarus he can't do anything till saturday 8th january, its the same as my original post, if i keep the car below 3000rpm it drives fine really sweet infact rev counter fine, no engine light, the minute i put my foot down in any gear and try to take it to 4500rpm the car jerks missfires backfires check engine light comes on and the rev counter drops to zero with the engine still running, the temperature guage will start to rise if i touch the throttle, i completely let off for a second or two it sorts itself out the miss fire stops the rev counter corrects, the temp will stay in the middle,but the idle will fluctuate extremely 0-1000 rpm it will not idle properly until i turn it off,

when i first went to extreme subarus he didn't really seem like he wanted to help and he said he had never seen this type of behaviour before, so going back there i cant really see him doing much, peple like yourself on this forum have give me more help in a day than he has all week

subaru1994

iTrader: (2)

just been through all the paper work for the subaru and found all the reciepts the z4 ecu was fitted on the 16-10-02 it was a version 2 Z4 ecu with stage "3" chip and remap of car costing a total of £741.00 inc vat

and then another reciept for a final map on 1-11-02

this was all done at midland impreza ltd alond with a speedo conversion and derestrict to impreza wrx

if this means anything

Glowplug

iTrader: (8)

Yeah that might help us out a little more fella.

So many different sensors on the Scoob mate. You really do need to do the reset procedure and post the fault codes so you/we have an idea of whats occuring.

Very 'odd' behavior. Not at all encouraging.


Get those codes mate and you'll get more help than you can handle. That is what SNet is about.

Glowplug

iTrader: (8)

The pics should make interesting viewing. Chipped and mapped would sound like an ESL board, we'll see.

At £741 i would want an Apexi for that

Speedo de-restricter is the 112mph Jap restrictor being lifted.

willsy369

i have a similar problem mate i get to 4500rpm and it holds back and misses, if i go steady i can get full rev range, mines V5 sti and im boosting at 1.2 bar, mine never did it until i fitted the induction kit so i think my MAF has gone 3 months later, ive also heard of a nightmare story of warped heads hope it isnt that pal, sorry to hijack thread just intersted incase your fault helps my similar problem. i also got told it could be fuel related due to a tank of bp ultimate and i normally use v power, also heard it could be fuel cut off or spark plug gap? mines set to 27 thou which is around 0.7mm i believe. i dont have the engine check light or rev/speedo issue though

subaru1994

iTrader: (2)

i will post the codes tomorrow evening, and i will post a video aswell to show you all what it is doing, i gapped my plugs and they were also gapped 0.7 but the tips were a lil white which means it running lean, its got a ****ty cheap induction kit that the old owner put on, it looks mickey mouse and has probly something to do with it

Glowplug

iTrader: (8)

Did you note the make and model of the plugs? NGK PFR6B are standard, gapped as you did.

Did you check the condition of the coil packs on the end of each lead? The ceramic behind the rubber is known to crack and cause major running issues.

A good idea would be to source yourself an OE air-box and the associated ducting.

dj219957

are the coil packs oe ones as well. mines was missing and back firing on hard boost and it was one cracked coil pack.

subaru1994

iTrader: (2)

hi guys,
uploaded pictures into photo gallery two of the ECU and one of the air filter to see what you make of this ran an ECU fault code check and the codes came back as 22 knock sensor and 31 throttle position sensor or circuit could these be causing my problem? i will also upload the videos later.

Glowplug

iTrader: (8)

Good man.
Yeah, a faulty knock sensor will pull your timing wildly, and TPS, of course, if the ECU thinks your throttle is in a different position to where it actually is will cause major issues.

Just going to look at the pics now.

subaru1994

iTrader: (2)

http://www.youtube.com/watch?v=uUV_Fl4N27U
thats the first video showing what the car does when i hit a certain speed.
http://www.youtube.com/watch?v=GxL1lnH6nqo
this is the second video of what happens when ive stoped after the problem occurs
the rev counter only drops in the video when i change gear and the dumbvalve kicks in if i was to keep in the same gear it will just keep misfiring but the rev counter will still be ok. so should i change both these problems?

Glowplug

iTrader: (8)

Ok, firstly the ECU is a standard Z4 ECU, not chipped or mapped. The pic below shows where the chip or daughter board would be fitted:


The, for want of a better phrase, 'air filter assembly' WTF!!!!



Get it all off and replace.

Glowplug

iTrader: (8)

Right, talk to Sonic93, pm him, as per post #3.

You need the KS, TPS, the air box and ducting and even the MAF of his motor. See what he has left.

dj219957

OMG that filter and tubing! you say youve tried everything? the FIRST thing you should have done was replace all that filter and tubing with the proper airbox.

burbling1

iTrader: (1)

Post a pic up of the car, after seeing the air filter assembly I'm very interested in the rest of it.

Glowplug

iTrader: (8)

Good point. Engine bay specifically.

Where are you located Subaru1994??

subaru1994

iTrader: (2)

im located in Essex, i took it straight to a garage after the problem occured and he totally looked past it telling me that wernt the problem, but i was goin to rip it all off and fit a pipercorss induction, but after speaking to you guys im putting it all back with the original air box.

i will post some pics of the whole car you tomorrow for you, you will be suprised the car actually does look nice

Glowplug

iTrader: (8)

That's that plan out of the window then!

That, imo is totally disgusting! He shouldn't of even attempted to replace anything accept the intake duct. What a w@nker.


Unless you have a fmic and are going for big figures the OE box is perfectly capable.

As i said above, i'm more interested in the engine bay. As if the previous idiot, (sorry, i mean owner) was happy to run about with that on, then there is no telling what else they would consider suitable.

Here is your starter airbox. Sonic93 may not have one as he has an IK fitted.