Boost reading / electrical issue perhaps?

[chrismit]

Hi guys

Wonder if anyone could shed some light on an issue i am having with my rev1 turbo

the fault is intermittent so its hard to pinpoint exactly when it is going to happen.

So the car will fuel cut and give me the error code for excessive turbocharging and wont allow me to go into positive boost pressure until i turn off the ignition and back on.

The 'fuel cut' is not happening at a particular PSI although it is more likely to happen when am i on full boost as opposed to low boost but this can occur when i am on low boost also.

My first thought was maybe i have a boost sensor fault and its sending an incorrect signal, so i replaced that with a known working sensor which did not give me any results, same issue.

The next thing i tried was blocking up the vacuum going from the air intake to the map sensor, so at this point i would think that all fuel cut has been defeated and it would be potentially unsafe but i do have my boost under control with my Blitz EBC and do not have issues with it creeping up. But still i am getting the same issue.. fuel cut and the same excessive turbocharging error code and the boost sensor circuit fault one. To my understanding the only thing capable of initiating the fuel cut is this sensor sending the correct voltage indicating my boost pressure is too high so how can this be occuring when there is no boost pressure going into the sender?

One thing to note is that even with the boost sensor hose disconnected and blocked off the boost sensor on the dashboard (built in crap one) seems to start the journey on no reading but after driving it will slowly rise to the point of reaching the mark on the line of -/+ before it would go into positive pressure.

What do you guys think, wiring issue? maybe my ECU is having issues?


Any help would be greatly appreciated

Thanks

Chris

[chrismit]

Anyone?

Just to confirm also i have cleared the codes so its the same ones reoccuring

[bobhatton]

What code are you getting?
So you have taken the hose off the MAP sensor and put a bolt or somthing to block off the hose?

What boost are you running?

[chrismit]

Hello

The codes i am getting are 34 and 35

Yes i did exactly that, cleared the codes and then after a period of time the same thing occured again with the 34 and 35 after a fuel cut, which i cant understand with it getting no reading to the map sensor (well of positive boost pressure anyway)

I am running about 0.9 bar of boost, i do have an aftermarket ecu cannot remember the name off hand, that is supposed to increase the boost limit over the stock on the rev1

[chrismit]

I could understand if maybe the ECU has been mis sold and the stock level of boost on my rev1 is only at ~12psi but this issue is happening when the map sensor is not getting any reading?

I have also had a HKS FCD hooked up to this in the past and it was the same intermittent issue as it is without it.

[bobhatton]

i do have an aftermarket ecu cannot remember the name off hand, that is supposed to increase the boost limit over the stock on the rev1

Not sure how an ECU can increase boost.
Have a look and see what this ecu is please

[chrismit]

Not sure how an ECU can increase boost.
Have a look and see what this ecu is please[/quote]


Hello, thanks for replying

By increase boost limit I was meaning the psi at which the fuel cuts

Ive had a look the ECU has the following on it

3S-GTEU

G.S.S Magic-CP

<3S-GTEU>TYPE SYSTEM

followed by lots of Japanese writing

Also has a big sticker in the middle of it that says

Grand Slam

SKY Tuning

Bought this a while back when I saw it for sale, it was claimed to have benefits I guess similar to something like a blitz access ecu, increased rev limiter fuel cut increased etc.

[bobhatton]

I would go back to a stock ecu, then sort out any problems before using this ecu again.

[chrismit]

I dont have any other 'problems'

I am simply wanting someone to confirm that with the map sensor not getting a reading from the intake manifold, as its a hose with the bolt in the end, the ecu is not taking anything else into consideration and the reason i am getting this error is down to an issue with the ecu or wiring somewhere in the circuit