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Old Dec 30, 2008 | 05:01 PM
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Default Fuel CUT

Hi people.

Replaced my boost solenoid today and im getting fuel cut's when reaching 1.0 bar, a friend of mine tested his ecu in my car. it was a Z4 and the fuel cut didn't happen. He advised me to change my ECU and that should solve the problem!!

His he leading me down the correct path or is there something more serious in this issue??

Any help/suggestions will help.

Thanks

Carl
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Old Dec 30, 2008 | 05:06 PM
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Depends on the year m8?, dont think 1 bar would hit fuel cut.






Runs off to check lol.
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Old Dec 30, 2008 | 05:12 PM
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Fuel-cut for a std 1993 WRX's OEM ECU is 1.0bar, so that bears out (should maintain boost at 0.8bar if everything's working fine).

So your car's obviously overboosting for some reason...

Last edited by joz8968; Dec 30, 2008 at 05:14 PM.
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Old Dec 30, 2008 | 05:17 PM
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Does the bottom hose have the restrictor pill in it?

My old 93 wrx ecu used to fuel cut a lot in the cold but when i changed to the Z4 it has never done it since
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Old Dec 30, 2008 | 05:24 PM
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Originally Posted by myblackwrx
Does the bottom hose have the restrictor pill in it?

My old 93 wrx ecu used to fuel cut a lot in the cold but when i changed to the Z4 it has never done it since

restrictor pill???

btw it has a TDO5 turbo fitted. Full 3" decat. When the Z4 ECU was fitted it ran 1.2 bar OK
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Old Dec 30, 2008 | 05:34 PM
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it shouldn't run 1.2 bar unless the ecu has been modified or you have a boost controller and fuel cut defender.

There is a restrictor pill in the bottom hose of the boost solenoid i just mentioned it as most people don't know that there is one.
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Old Dec 30, 2008 | 08:06 PM
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it dont run 1.2 bar on standard ECU it was the Mines Z4 what i put in that it ran 1.2 bar
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Old Dec 30, 2008 | 08:26 PM
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Originally Posted by Carl Bentley
it dont run 1.2 bar on standard ECU it was the Mines Z4 what i put in that it ran 1.2 bar
Yeah but I think mbwrx was getting at the fact that a standard Z4 doesn't boost cut at 1.2 - it's a shade under 1.1 bar (15.65psi).

But now that you've mentioned Mines, that implies that the Z4 has a Mines chip in it doesn' it? ... which prob runs at 1.1bar and, therefore, boost cut at 1.2bar (limit of your MAP sensor).

This is all getting away from your original problem (i.e. that Mines 'control' ECU is not helping in this troubleshoot), in that, for some reason, you're overboosting on your OEM fitment ECU.
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Old Dec 30, 2008 | 08:30 PM
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Yes.. and i would like to know why its overboosting and cutting fuel.. Since changing the boost solenoid which was foobard it was running @ 0.8 bar fine. But why after changing the solenoid its boosting past 1.0 bar ??
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Old Dec 30, 2008 | 08:40 PM
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if it was running 0.8bar fine why was the boost solenoid fubar?

the restrictor pill as mentioned is probably missing.. the bottom hose off the boost solenoid should have a small metal restrictor in it.. smaller than a pea with a hole drilled in it.

Mines ecu is a bad move imho.. who would name a tuning company after a bomb?
They have iirc no fuel cut and run way too much ignition and usually an explosion occurs..

Simon
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Old Dec 30, 2008 | 08:45 PM
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Originally Posted by Jolly Green Monster
if it was running 0.8bar fine why was the boost solenoid fubar?

the restrictor pill as mentioned is probably missing.. the bottom hose off the boost solenoid should have a small metal restrictor in it.. smaller than a pea with a hole drilled in it.

Mines ecu is a bad move imho.. who would name a tuning company after a bomb?
They have iirc no fuel cut and run way too much ignition and usually an explosion occurs..

Simon

It wouldn't boost at all, so replaced and now it does, but cuts @ 1.0bar

How do i find out if the metal restrictor is missing? (and how do i get a replacement restrictor)

The mines ecu worked well @ 1.2 bar but cut after that.

For some reason it just keeps on over boosting.
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Old Dec 30, 2008 | 08:55 PM
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Didn't realise you had a Mines ecu hence my comment sorry

Boost Solenoid Plumbing shows where the restrictor should be if it is missing you can buy them from a dealer but i think it has to be certain size which idon't know
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Old Dec 30, 2008 | 09:02 PM
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did you use any different hose or just swap the boost solenoid?

also have you connected the top hose to compressor cover, middle to actuator and bottom to inlet (which is the pipe the restrictor needs to be in)?

Simon
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Old Dec 30, 2008 | 09:04 PM
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Originally Posted by Jolly Green Monster
did you use any different hose or just swap the boost solenoid?

also have you connected the top hose to compressor cover, middle to actuator and bottom to inlet (which is the pipe the restrictor needs to be in)?

Simon

Don't know, he changed it and i didn't take much notice.

Gonna get my halogen lamp and take a look
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Old Dec 30, 2008 | 09:25 PM
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Here is the solenoid pipes


Last edited by Carl Bentley; Dec 30, 2008 at 09:31 PM.
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Old Dec 30, 2008 | 09:41 PM
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Is this how it should be??? Please ring 07939419962 if you have time atm to discuss the location

ImageShack - Image Hosting :: p3012082141xh1.jpg
Little pipe inside

]ImageShack® - Image Hosting
connected to here

ImageShack - Image Hosting :: p3012082142co2.jpg
Connected to top of solenoid

Last edited by Carl Bentley; Dec 30, 2008 at 09:58 PM.
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Old Dec 30, 2008 | 10:07 PM
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OK just took of the bendy pipe that goes to the air box.. It don't feel like there is anything inside of it.

I'm guessing if this restrictor goes in there the fuel cut off won't occur. ? ?
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Old Dec 30, 2008 | 10:09 PM
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Originally Posted by Carl Bentley
Is this how it should be??? Please ring 07939419962 if you have time atm to discuss the location

ImageShack - Image Hosting :: p3012082141xh1.jpg
Little pipe inside

]ImageShack® - Image Hosting
connected to here

ImageShack - Image Hosting :: p3012082142co2.jpg
Connected to top of solenoid
first pic - that is just a connector adaptor from large to small pipe

last pic - the bottom pipe should connect into the pipe that goes to the inlet resonator with a restrictor in it.

there is a lot of horrible pipework in that engine bay.. copper pipe to blue silicone with no clips holding it on etc.. what is the brass item cable tied to the dump valve take off?

it could of course be be overboosting just because the weather is damn cold and damp air at the moment..

Simon
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Old Dec 30, 2008 | 10:10 PM
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Originally Posted by Carl Bentley
OK just took of the bendy pipe that goes to the air box.. It don't feel like there is anything inside of it.

I'm guessing if this restrictor goes in there the fuel cut off won't occur. ? ?
yes
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Old Dec 30, 2008 | 10:11 PM
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where can i get one from?
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Old Dec 30, 2008 | 10:22 PM
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Originally Posted by Jolly Green Monster
there is a lot of horrible pipework in that engine bay.. copper pipe to blue silicone with no clips holding it on etc.. what is the brass item cable tied to the dump valve take off?


Simon
Its not a cable tie.. Just my crappy phone with my halogen lamp shining.. Its actually the blue pipe with a jubilee clip
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Old Dec 30, 2008 | 10:33 PM
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Originally Posted by Jolly Green Monster
...Mines ecu is a bad move imho.. who would name a tuning company after a bomb?...
Sorry, but that made me laugh .

But a fair point - as it reminds you of blowing up, explosions and stuff... Oh the irony of it!

Last edited by joz8968; Dec 30, 2008 at 10:34 PM.
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Old Dec 31, 2008 | 09:27 AM
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Ok just rang the guy. He didn't change any pipe work. He said there's a wagon ECU in it, and thinks there was a problem before this and so they just stuck a standard ECU in to cure the 1.0 bar boost cut.

What can i do??? I'm confused

What bar does my turbo produce?? TD05
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Old Dec 31, 2008 | 10:34 AM
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if they put a wagon ecu in it that's unsuitable as they were meant to run a TD04.
Your turbos boost is limited by the ecu and if the correct ecu is in place

WRX/STi Saloon ECU's 2C, U8, W6, W9 - As above, 11.47psi held to redline. Fuel-cut 14.57psi
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Old Dec 31, 2008 | 02:15 PM
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All sorted. Lad who fixed knew what he was doing.. Have now got Z4 ECU and don't boost cut.
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Old Dec 31, 2008 | 02:34 PM
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Good to hear
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