gazturbo1

hi there im having afew problems with the wrx at the moment ,its a lreg. Well whats happening is the moment it hits 4.5k it feels like its hiting fuel cut.. I have tried reading the ecu by connecting the green wires together and black wires but no fault codes have came up. I have vacumn tested all hoses to the boost solenoid and they are ok, every gear this fault hapens and its driving me mad! Any help appreciated cheers

porteouz

iTrader: (1)

Maybe the boost solenoid itself?

Do a search on here mate there are countless threads on the subject.

scoobiewrx555

Might be the MAP sensor on it's way reading more manifold pressure than there actually is or it could be that you are massively overboosting. They read just over 1.2bar so if you're exceeding that it will induce boost and fuel cut.

It won't neccessarily throw up a code though if it's faulty.

gazturbo1

hi i just checked the boost presure and it spikes 2 1.2 bar on gear change but is 1.1 while in 3rd gear. Then it wil just hit fuel cut

scoobiewrx555

It could be the MAP sensor but it sounds like it's cutting out thereabouts where it should be.

I would replace it with an uprated sensor from a later v.3 or v.4 1.7bar type but then you will have to get your ECU remapped because the MAP senor table will need rescaling.

The fact that it's spiking to 1.2bar tells me that if it's not been remapped already (ESL) then it's been chipped. Is it chipped??

gazturbo1

hi the guy i bought the car from has said it wasnt chiped il get hold of the map senser required and see if that helps it does have a tdo5

scoobiewrx555

If you are not going to get the car remapped then don't get the uprated 1.7bar MAP sensor, stick to the std OEM rated sensor from another v.1 car. Get a 2nd hand one from somebody like Grade A Subaru. Andy is a top man and will sort you out.

bigsinky

does it have a manual boost controller like a dawes device or similar

scoobiewrx555

The MAP sensor monitors the amount of air pressure in the inlet manifold. That helps the ECU regulate everything from turbo boost to idling and is therefore an important part of the process.

You're thinking about the boost control solenoid. Generally if that packs in you end up making little or no boost apart from natural wastegate pressure so with the problem you have it sounds unlikely your issue is with the boost controller.

If the restrictor pill in the boost controller rubber tubing (vent port bottom of controller leading to the turbo inlet/intake hose) is blocked up it may well lead to overboosting as it's not bleeding away sufficient/any air therefore keeping the wastegate duty very high and hence your overboosting. Check it. You should be able to undo the hose from the bottom of the controller and blow through it to see if it's blocked. It's a very small hole (about 1.2mm) so although it might be hard to blow through you should still get air coming through.

gazturbo1

right ok. I have ordered a chip from major sarcasim unsure weather id need further maping if i had the 1.7 bar map senser?so i would probably think a standard one should be used. anyway i have had the car pluged in with a select monitor no current dtcs. But it does have historic ones of 42 idle switch,33 vehicle speed senser,32 oxygen sensor,31throtle position sensor circuit,24 idle control system malfunction 22 knock sensor would any of these cause overboosting? Cheers

scooby1929

iTrader: (1)

Could be some dodgy fuel!! First thing I would do is disconnect the battery and this will reset the ECU. I had this prob on mine and it never came back after i reset the ECU. Just a thought tho!!!

gazturbo1

i have tried the reset mate but no joy. I guess ill clean the boost solenoid and replace the map sensor see how i get on.

scooby1929

iTrader: (1)

Ahh dead on mate!! Hope you get it sorted

scoobiewrx555

Don't go fitting any chip until you've cleaned out the boost controller and checked the restrictor pill to make sure it's unblocked. If once you have changed the map sensor there is still no change then a chip isn't going to fix your issue and neither will a manual boost controller.

IMHO chips are nothing but a cheap one size fits all very poor solution (if your car has mods) to something that can only really be sorted with a remap. You gets what you pays for and in the long run a chip will be nothing but a PITA and very likely to cause you issues at some time in due course.

If you love your engine remap the ECU, don't chip it.

gazturbo1

hi well i think i have found the problem ,the large hose which goes to the turbo has a hole in it fairly decent the rubber one could this cause it?

and well my plan is to get it on the rolling road and have the fueling ignition timing, boost checked anyway as i would prefer it safe.

scoobiewrx555

Are you talking about the turbo inlet pipe that goes from the airbox/induction kit to the turbo??

If you have a hole between the MAF and the Turbo then it will run a bit leaner as the engine is taking more air than has been metered by the MAF but i don't think it would cause your fuel/boost cut unless it was running really lean and you got knock (detonation). Your ECU would try to compensate by adding more fuel and retarding ignition, if that didn't work then if it was really bad you'd go into limp mode.

gazturbo1

yes i am ,well i guess ill get that sorted anyway as i dont want it running lean.
i have got a maf to try, and a boost solenoid.
where is the map senser is it one of the ones bolted by the boost control solenoid?



cheers

scoobiewrx555

Yes, it's got a single vacuum pipe going to it and it's bolted right next to the boost control solenoid.

sy.

iTrader: (8)

As posted in the wmi section if ya need any help you are very local to me drop us a pm

gazturbo1

scoobywrx555-thats great least i know which one it is now thanks for the info and help

sy- cheers that would be great i hope i can get it sorted but if not ill drop you a pm

gazturbo1

thaks for all the help guys im hoping this is sorted as the problem hasnt occured today since fitting a map sensor!, so well done scoobywrx555 and thanks for all the help!
i also fitted a boost gauge today in psi and it is now running 14 psi in 3rd gear is this normal or would this suggest it has been chipped?


cheers



gary

scoobiewrx555

1bar still sounds a little over but much closer to the mark. Normally they're boosting at 0.8bar and analogue boost guages aren't the most accurate however it sounds like you're just about there.

Nice one!!

gazturbo1

oh ok thats great.
the ecu on my car is a w6 ecu is this normal for my car a l reg wrx saloon?
i have been offered a z4 ecu is this a worthwhile upgrade? i tried it on my car and didnt really fell much difference this was off a m reg wrx saloon.
both boost levels seemed the same around 14 psi peak boost.
i opened up the z4 ecu and it looked like somebody had put another board on themselves maybe a chip?
i opened mine up and all looked normal so was suprised no differnce in power the spec was the same too. what do you guys think?

gazturbo1

ahhh just found this looks like the difference isnt much but the z4 is worth while for remaping/ higher fuel cut. does that sound right?
WRX/STi Saloon ECU’s 2C, U8, W6, W9 fuel cut is 14.57 psi boost level is 11.47psi held to redline
WRX (1995/96) ECU Z4fuel cut is 15.65 psi boost level is12.71psi, dropping to 11.78psi @ 6600rpm



i realise whichever it would need to go on a rolling road to check fueling etc i was just interested to see which ecu was more beneficial.



cheers

scoobiewrx555

Z4's are mapped for c.260bhp. There shouldn't be a board or chip in there apart from the normal ECU board. If there is then either it's a board (ESL), that's OK and would need remapping, or some nasty chip which i would run from as far as poss.

In any case, forget the z4 and just have your original ECU fully custom remapped (ESL) to reflect any mods you've had done on the car. Then you really will feel the difference. ESL boards come as standard with Z4 mapping as a base and the tuner makes appropriate changes from there (all in real-time/on-the-fly).

gazturbo1

ok thats great thanks for the info

seppy101

i had the same problem mate, i got a manual boost controller fitted, cost me 27 pounds and then the labour on top, now its boosting better than ever... the fuel cuts to stop any harm to your engine. doesn't feel good tho, nearly throws you through the windscreen
also if you have an induction kit it can wreek havok with the maf sensors. but defo think about a manual boost valve.. hope you get it sorted