sti v2 96
have a 7k ecu with chip in car was running bad so bought new plugs coil packs,then did ecu check and im getting error code 45,first 2 gear ok 3 4 5 and cutting out and no more than 0.7 bar
took the ecu out put in a u8 ecu i have spare and im not getting code 45 any more, but it is still running bad in third forth fith wont go above o.7 bar and engie losses power suddenly and regains again
have checked that the plumbing is right and cant find any splits
matt

 

The U8 is from a wrx (92-94) not sti so i expect that's not helping.

 

i know ,it was in it when i bought the car did not miss a beat ,so i put it in just to see if the problems where there still and the error code has now gone but performance is still not right

 

Not nice of someone to sell you a car with wrong ecu.

when you say runing badly in the later gears is that normal driving or spirited driving?

 

not good finding wrong ecu in a sti ,never mind,good to have spare comes in handy for things like this
reset the 7k ecu with chip goes like stink then 3 4 5 gears wont go past 0.7 and stops for a second and in third to ,put other ecu in no error code ,drive hard and same thing happens
it seems like it must be one of the sensors in the cluster of boost, map, pressure

 

What chip is in the ecu?

Since 45 is pressure sensor/pressure exchange solenoid valve this may need to be looked at (although i have no idea what/where it is)

 

is one of scott t older chip, but it did it with the other ecu in the car aswell,so ive bought a second hand pressure solenoid to try that,
since ive put the chipped ecu back in it is not showing any code as i have not really floored it yet
spoke to scott a number of times and ill get a mbc valve if the solenoid does not do it

matt

 

DELETED and COPIED from other thread as was more applicable to this one.....

Have seen this on other cars (over the years) it appears to be a breakdown in the electrics which causes the boost control solenoid to stop/misbehave and can also lead to code 45 being logged i.e the ECU thinks it's controlling boost and gets incorrect boost measurements back from the map sensor so logs code 45.

Saw this recently on a car and after changing all of the boost control sensors & solenoids and after running several different maps and several different ECU we reverted back to the standard ECU to see if the fault could be provoked.

On the Tunnel run and running the Standard ECU it reared it's head again, so the map was well and trully ruled out (I've supplied enough since 2002 anyway to rule it out, but this was confidence inspiring).

The only solution was to revert back to the chip and use a Dawes valve to control the boost. Since then the car has been running sweet and has even done a few runs at Santa Pod.

P.S It's a bit harder to spot when running the standard ECU as the boost will only drop from 0.8 to about 0.6. If you havn't got a boost gauge it's the kind of drop that would be difficult to spot/feel.

 

The only other thing I would add is that the car in question above was monitored for Det and AFR and all was OK.
Initially it was detting due to a faulty MAF (it was detting even on a standard Z4 ECU), but with this replaced it was running fine. Then the whole issue of dropping boost and code 45 reared it's head a few weeks later.

 

I had error code on my 93 WRX a few years ago. From what I remember, the car would cut out when the boost rose too high (didn't have a gauge fitted at the time). I recall having to drive on a pretty light throttle and short shifting to prevent hitting fuel cut.

Tried a friends ECU and same error came up, so decided to change the MAP sensor (£30 s/hand from Grade A). This resoved the problem, and it's been fine since.

 

if i booked car in for a rolling road they would be able to tell me if fueling was correct and would spot det
car runs fine with normal driving its when you give it some biscuit,
a boost control unit manual or electronic would stop this or not
thanks matt

 

An r/r would tell you about any fuelling problems,boost problems etc but make sure you take it to someone who knows what they are doing (obviously).
They can then suggest a cause of the problem and hopefully a remedy.

 

a sweet would rather take it there in good running order,any good ones around bristol way