Just a thought but has your boost gauge ever gone over 0.9BAR? maybe it aint working properly

 

Not since I have had the car it has'nt. Was told that if I fixed the problem go careful cus the new chip would hit boost cut-out and to replace with the original chip. So I ruled this out?

Any takers?

 

well... On my car (MY93 WRX) the standard boost was 11.47psi and fuel cut was at about 14psi BUT the chip changes that so it boosts at 16.5psi (1.1Bar about) and ups the fuel cut to 18.5psi and Ive never hit this.

I'm not sure what chip you have but its likely to be the same type of map.

I'd check the boost gauge, borrow another one to test, if the cars running better and feels like it has alot more power the boost is likely to be higher than stock 0.9

Gaz

 

stick a volt meter on the map sensor signal and report back what voltage you are seeing at full boost.

Just jam the + probe of a voltmeter into Pin B43 Pin 4, and the - down to chassis.

 

Thanks Gaz and thanks Scott, will do both suggestions. In the mean time ponder on this. I have finally managed to find the diagnostic leads (hidden behind the alarm module and taped up). Fault code 43, Throttle Switch.

Does this ring true of the symptoms?

 

Scott, will do this as soon as I ge back from work tomorrow. What am I looking for, if the voltages are incorrect does the pressure sensor need replacing? (Boost solenoid???)

Does the UK 7D ECU make any difference, have got a U8 and a Z5 if not?

 

Error Code 43 is a red herring and is due to the 7D ECU you are using.
You also get that code when you fit the Prodrive chip into a UK car (with 7D & V7 ECU) due to the Prodrive chip also using a Z4 WRX base map.

I ran a UK car with initially a Prodrive chip years back and always got that code. It doesn't cause a CEL or any difference in performance, it just appears when you do a diagnostics check/ECU reset. So don't worry about it

Infact that code isn't listed for UK ECU Diagnostics :

Code ITEM
11 Crankshaft position sensor

12 Starter switch

13 Camshaft position sensor

21 Engine coolant temperature sensor

22 Knock sensor

23 Mass air flow sensor

24 Idle air control solenoid

31 Throttle position sensor

32 Oxygen sensor

33 Vehicle speed sensor 2

35 Purge control solenoid valve

42 Idle switch

44 Wastegate control solenoid valve

45 Pressure sensor –Pressure exchange solenoid valve

51 Neutral position switch

With regard to measuring the map sensor. This wasn't an attempt to determine if the sensor is faulty, but to verify what boost you are running.

At idle the voltmeter should read about 1.4 - 1.6V
At 0.9 bar is should read about 4.3V (approx)
if it's hitting 1.1bar is should read 4.65V (approx)

 

Okay doke. Talk later when I have the Voltmeter readings.

 

Scott,

Results are as follows:

Ignition on (Engine off) = 2.63V
Engine on at Idle = 1.31V - 1.34V
Full Throttle in 4th - 5th = 3.79V
What now?

 

Scott,

Could you PM me with how much you charge to supply these? I know you used to bung them on ebay but are you doing them "to order" now?

Cheers
Ritchie.

 

3.79V only equates to arounf 0.7bar according to the info I have.
Are you sure it's not in limp mode and that the boost control solenoid is working ?

With your head under the bonnet, crack open the throttle and you should hear the boost control solenoid start to click.

I have heard that the UK can cause a CEL in a WRX (the instance I remember though I think was a wagon) but I've never experienced a UK ECU in a WRX running a remap before.

I would expect the CEL to illuminate if it was in limp home mode.

If I were you I'd drop the U8 ECU in there and take the smae measurments and report back it should hit about 4V on the standard map.

 

Okay... Lets say I fit the U8 and voltage does read at 4V. Does this mean that the 7D ECU is not compatable? As mentioned, all seemed fine before the change-over.

I have ran the 7D with and without the chip and the CEL has never come on..

Not sure if 'BCS' is good working order, can I test it?

 

A good enough test of the BCS is described above.

 

Nuff said.. Will try the U8 tomorrow and give an update.

One more point I should mention, it may eliminate something!

BCS was clicking on very light throttle so I adjusted it within the parameters of the table above and this has eliminated the click at light throttle. Its was reading at 4.8V and now is correct at 4.7V closed.

My next post will be the result with the U8.

 

I can't hand on heart say a 7D will work in a WRX. The theory says it should but I have heard of people fitting them and getting a CEL or Error code. If it's just Error 43, as mentioned above this is a red herring.

But I have also heard of people running a 7D in a WRX. Infact there was one guy on here a while back that was running a 7D with boost and fuel controllers to very good effect as I remember commenting that the 7D was not the correct ECU for a WRX.

 

Hi. Results with the U8 ECU fitted are as follows.

At full throttle in 4th it made 4.0V. However it was a hesitant 4V.

I could only describe it in text by saying it was like very slight kangaroo hops!


BCS does tick away quietly when the throttle is opened.

What are your thoughts?

 

Also just found this pipe disconnected, anyone know where it belongs?

The picture is taken inbetween the 'L' Shaped Airbox and the Boost Solenoid. The disconnected pipe is the right hand side of the 'T' piece.

http://i123.photobucket.com/albums/o...0/100_1234.jpg

 

have you replaced the pipe that comes out the bottom of the boost solenoid with after market boost hose? (The pipe goes out the bottom of the boost solenoid that would normally go to the resonator box just after the MAF)

 

Unfortunately it was like that when I bought the car so I don't know how it was before.

 

well I replaced the other two hoses with after market pipe but the bottom one which goes to the resonator has a restrictor in it and when I replaced this with boost pipe that didnt contain a restictor I was getting alot of over boosting and hit fuel cut once so replaced it with standard. I know yours isnt doing this but it could cause problems with the boost solenoid.

When I had the after market pipe without the restrictor the BCS was ticking its **** off when under light throttle once replaced it hardly makes any noise.

Again its somthing to look into / think about,

Gaz

 

I think what I will do after Scott.T get to the bottom of the ECU questions is see Subaru for a set of OE BCS related pipework, and hopefully that will sort the hesitation. Or maybe a new BCS is the order of the day. I live in hope.

So frustrating is'nt it when things don't quite work how they should. The car goes very well but it is just not quite right. I thought the chip install would be easy, all its done so far is highlight the underlying faults. Can't wait to get it sorted.. Gutted.

 

I have now fitted the chip in the Z5 ECU and again have taken readings.

Max voltage in 4th and 5th is 3.85V. The reading is still low but no hesitation on boost.

 

A bit strange, chip increase BCS duty yet boost goes down.
My immediate thought is that the BCS is plumbed up wrong.

Try connecting as follows :

1. BCS top connection to Turbo outlet nipple
2. BCS middle connection to Actuator
3. BCS bottom connection (which should have the little brass restrictor in it) to Air intake resonator box or VTA if airbox has been removed.

If it's already connected like this then swap 1 & 2, as I can't remember for sure for a Pre96, but thats how my 3-port is plumbed in my MY00.

 

I'll try it. I will not be able to do it until Tuesday/Wednesday as I have it booked in for a new clutch which I noticed was slipping on Friday. Great int it!! Thanks for all your help so far and I will let you know how it goes..

Dan.

 

Connections are as I said above, and confimred here https://www.scoobynet.com/general-te...id+connections

 

Thanks..

 

Right.. Hello again all. The car is back from garage.

Boost solenoid pipework is not quite as you say Scott. Here I have taken a photo. The bottom pipe from BCS is the one I mention before. It does go to the Resonator Box but I can't feel any restrictor and it goes via a tee piece, you can just see it at the bottom of the photo.

I take it that I should replace this pipe first before we go any further. Question - Is this pipe with the restrictor the same on UK and WRX Impreza's?

Your thoughts?

http://i123.photobucket.com/albums/o...0/100_1275.jpg

 

The bottom hose shouldn't have a t-piece in it but should just plumb straight back to the resonator/expansion box or vent to atmosphere if you have an induction kit without the required nipple for the hose to connect to.

It should have a restrictor in it and yes a UK and WRX part is the same.
If you have no restrictor you should see boost spikes and slightly above standard boost pressure, so I don't think this is the main problem.

I've just had a look and the rather complicated diagrams on the Part DBase and I can confirm :

Turbo outlet Nipple - Top Connection on BCS
Actuator - Middle Connection on BCS
Resonator Expansion - Bottom Connection on BCS (this hose includes the restrictor/orrifice)

The Pressure Exchange Valve (the brown/orange thing in your picture) should conect to one of the 3 vacum connection on the top of the inlet manifold just infront of the throttle housing.

The outlet from the pressure exchange solenoid goes to the map sensor, which I can see from your photo is correct.

 

It goes to the manifold..