I have a 93wrx which has always run at 0.7 bar boost pressure (measure on a SPA digital gauge) I recently fitted a scoobyecu which should run at 1.02 bar but my peak is 0.93 and it holds at 0.85 bar. Scott T told me that a standard 93 wrx should hold at 0.8bar and the new ecu at 1.02 so I seem to have a low boost problem.

I have checked the CEL but no codes present. My only mods are an ITG filter and scoobysport exhaust from the downpipe back.

The boost solenoid was cleaned out in May and the intercooler hoses have been changed for Samco ones

Can anyone tell me where to start looking for possible causes of this problem?

[Edited by Charlie H - 10/6/2003 12:27:25 PM]

 

ecotech - do you mean the intercooler to turbo pipe? If so this has been swapped for a samco one as the original plastic one had a crack in it

[Edited by Charlie H - 10/7/2003 6:59:58 PM]

 

Not much else then David I suppose I asked for that At least it gives me something to look at (not that I know how do check things like the actuator)

[Edited by Charlie H - 10/8/2003 5:00:46 PM]

 

MAF sensor? Wastegate? It should open at 0,7bar if you try it directly with a pressure pump.

K.

 

Charlie H,
I had the same problem on my 94 wrx wagon , which scott t supplied a scoobyecu for and it was the driver circuit in the ecu playing up(according to scott) so i by-passed the boost control solenoid and fitted a dawes device set to 1.2 bar in it's place , that was probably 6 months ago and it has run like this without any problems,
hope this helps.

Matt.

 

Sounds like you have a porous or leaky hose some where on the to / from boost solenoid / wastegate circit?

Not sure how you check them, but replacing them one by one would help.

 

Webster - I have spoken to Scott who thought it might be a clogged boost solenoid pipe or a weak actuator. I'll also check all the pipes. I don't think it has anything to do with the ecu as my boost gauge read the same on my previous ecu which broke in May (due to my stupidity )
Problem is I'm not very experienced in turbo boost faults and wouldn't know how to check the actuator etc anyway.

As I stated earlier, my boost solenoid was clogged up in May so I may try and clean it and all the pipes out again. I just wanted a list of things to try/check, and the last 3 posts have given me something to concentrate on.

 

check the pipe thats bolted underneath the intercooler.

 

Any other ideas?

 

hmmm...

Leaking dumpvalve.. split boost hose.. actuator.

David

 

Charlie,

As mentioned in my email, clean out the very bottom hose from the boost control solenoid and also make sure that the airway is clear where it enters the intake expansion box.

If that doesn't work then remove the bottom hose all together and go for a run. This will remove the brass restictor from the circuit and hence allow more air to be bled away and hence cause more boost to be generated (it may even cause fuel-cut).

If this works it may well be the actuator that has gone soft or is not set correct. This should then be shortened by 1-2 turns. It should be tensioned as it clips over the wastegate and not just fall on.

Alternativly is it hit's 1-1.1 bar with the hose off and the actuator maked no difference, you could just increase the size of the hole in the brass restrictor (in the middle of the solenoid bottom pipe).

The duty cycle on this map does hit 1.05 (ish) bar, normally reads nearer 1.1bar as I have had this confirmed from several sources.

 

Cheers Scott I tested the V10 chip last night. I'll send you an e-mail about it soon I'll try V11 this weekend