Hi all,
I'm hoping someone might know what this is as it's been going on a while with my Import 96 WRX and I've tried to fix it myself so far but to no avail . The problem is that when I'm accelerating (say on a motorway slip road) and I change typically from 4th gear into fifth gear instead of giving me full boost it seems to give me half the boost-I believe the car is going into "limp home" at this point as from then on, until I turn off the car it is only giving half boost in the other gears.
It's very inconsistent I thought but I know believe that it's only happening when the engine is at its heaviest load and changing up to fifth gear (accelerating hard). It has boosted fine in fifth gear before but I think it only happens in this gear to start with and then does it in every gear there after. Very inconsistent. Most of the time my car drives well which is why it's so annoying when this happens. Weather makes no difference, happened in cold/hot, wet/dry.
I've checked all my pipes and jubilee clips and all seems fine. I recently cleaned out my boost solenoid (connected green plugs etc/clicks away) and that didn't help. There are no error codes at current.
I have a boost gauge and it does not appear to be over boosting or hitting a fuel cut as I know what that's like.
The engine is very well maintained, with oil changes at every 3/3.5k miles, plugs and coil packs all only a year old. 260bhp, Apexi induction kit, Blitz cone filter, 3" straight through exhaust, API re-built engine (9k miles ago), ported header, light weight flywheel...Not sure what else you'd need to know but if anyone can point me in the right direction that would be appreciated. Gareth
I wasn't going to worry about this as I was going to have a re-map soon & get it looked at before that but now that's put on hold as I'm looking for a new job (like so many made redundant) so I wanted to try and solve this if I could.

 

My Newage was doing this boosting to 1.4 then back to 0.6, the induction kit was causing the maf to lean the mixture out too much causing detonation, and basically the boost drop was the engine attempting to save itself...only appeared when the weather got warmer ie not enough cold air about, I put the standard airbox back on and all has returned to normal.

 

What DV have you got fitted?

Si

 

I've got the standard re-circulating dump valve on there. Do you think that could be causing the problem? It is probably 13 years old now.
And for the guy who mentioned the induction kit, it's been on the car since I got it (filter element changed for new 1 year ago), after the engine was re-built I had an over boosting issue which was traced to a boost adjuster set too high, removed it/back to standard then it ran fine. Maybe 3/4 months ago I started getting this problem. Do you think I could be having MAF issues? if so, why only high gear? Thanks for all and any replys. Gareth

 

check the pipes for a tiny brass restrictor i had this issue like this when it didnt put i back in the boost pipes.

 

Just checking but that's the restrictor pill thats in the pipe coming off the bottom of my boost solenoid and going to my air box resonator (induction kit in my case) right? It's a pain to get off, any suggestions? and I'll look tomorrow. Thanks

 

My induction kit was fitted 6 months ago and has been fine, only been a problem in the warmer weather, I am not overly tech minded but apparently the knock detector was sensing detonation and backing the boost off..this only occured at high gears, followed by an engine management light....

 

I checked my pipe work today and I've found out that the restrictor pill isn't in the pipe. I was going to get one from CVC but as normal it's an import and they couldn't help. I'm going to ring API tomorrow to try and get the correct one. I'm hoping that solves my boost issue. Thanks for all the help so far everyone.

 

If i remeber right the pill goes in the pipe between the actuator and turbo. find a scooby thats being broke or in a scrapyard.

 

Hi Ant,
Thanks for your help so far. After more investigation my car should not have a restrictor pill in it as it's an import 96 WRX and these did not have them. It's in the UK versions and newer Imports but not mine.
I thought we'd solved it thenDamn it!
I've checked as much as I can for now and the car ran lovely today but I know it's ugly fault will show up again soon. For now I'm going to live with it until I can get some fund's together and get it sorted at my favourite Impreza garage. Thanks for all your info everyone.

 

They do have them i had an my96 car straight intercooler facelift one and that had it.

 

Mine was wrx to

 

Really?
That's strange because the garage I got my info from are usually spot on. My car is a Japanese (imported) 1996 (N reg) Subaru Impreza WRX. Not an STi or anything, is that still the same??
Who told you or how did you find out that was the problem? sorry for all the questions but it's just hat if that's all it is then I should be able to fix my fault with this pill.
Do you have a part number, or definative size as there's all different sizes?
Thanks Ant, all info appreciated. Gareth

 

i have a spare one if you wanna try it out and see if thats the problem, well i have 2 u can try and possible a 3rd or 4th. lol

 

mine was a p reg 1996 facelift one with straight intercooler, and im sure stis are the same layout in the pipe work and ristrictor.
I knew what the problem was becuase i renewed all my pipes with blue hose when i fitted my td05, and forgot to fit the pill back in.
Sorry no part nos or anything as i already had mine.

 

Yeah but if your cars a UK version then it's different to the Import version even if it's the same year. Mine has a slanted black intercooler and is a 260bhp Import version. I'm going to do some ringing around for info and see what I can find out definitively.

 

Mine was JDM was wrx 280ps.

 

Ok, thanks Ant, I'm going to have a look and ring around on Monday to see if I can get the correct one. It might still be that mine doesn't have one because it is slightly different to your car as mine is less horsepower, different intercooler arrangement and slightly older (N reg 1996) non face-lift. I really hope your right though . Thanks for the imput so far.

 

Have you had any luck with this.

 

Sort of...garage found the problem, combination of faulty DV and something on the boost control side of things. Had it booked in to get fixed and the day before it destroyed third gear.
Getting it back tomorrow with all problems fixed and no money left to buy petrol Gotta laugh really haven't you or you'd cry otherwise, still love it though & can't wait to pick it up. Thanks for all your input and help.