Had a 360bhp 2WD sapp Cosworth but sold because it kept blowin headgaskets for breakfast! I bought a 1994 WRX 4 weeks ago and its great, It was overboosting off the 1Bar gauge and being cut off when i picked it up. Had it serviced and solenoid cleaned, dump valve checked, map sensor cleaned out. This cured the prob in a way.
Now i get a solid 1 bar boost for about 5-6 miles, then it holds back at 0.5 bar and wont budge. If i pull over turn off engine for 30 secs then start again i get a few more miles at a higher boost. The car is standard bar a CAT back stainless HKS i think.
I check the fault codes, its all ok

PLEASE HELP!!!!

 

For starters 1 bar is above standard for a 94 WRX

Had a similar problem with a WRX at the weekend, kept going into limp mode but with no codes. Logged the AFR and it was all over the place and kept dropping boost.
Swapped the MAF and it boosted fine, fuelling was richening up as expected and it didn't go into limp mode.

The guy swapped MAF back and it carried on miss-behaving. It was suggested he cleaned the MAF with carb cleaner i.e spray it and clean it with cotton bud.

This he done, and AFAIK it hasn't yet gone back into limp mode.

 

Cheers will go try that now, thanks for a fast reply!

 

nah didnt work, it hits about 0.4 bar and stays there feels very assmatic.Really annoying you cant even hear the turbo spooling up or the recirc valve. Any other ideas??? ANYONE.......................?

 

Safe mode?

 

Whats that? i am new to these cars? safe the same as limp? no pun intended

 

Scoobypedia | Trusted knowledge for everything Subaru | Scoobypedia browse will tell you how to read any error codes.Worth checking the ecu for any extra chips (under passenger footwell kickplate)



This is what the ecu should look like but if there is a chip in the bottom rhs row of solder that may be causing problems (perhaps).

Limp home mode only lets you rev to 4000 revs and boost to 0.5bar

 

it will rev to the limiter but only goes to 0.5 bar, this gets weirder???

 

Possible fuel pressure problem. Check the hose from your inlet manifold to your fuel regulator is attached correctly and the hose has not damaged.
Maybe under fueling at higher boost pressure due to fuel regulator not increasing fuel pressure with increased injector cycle.

 

Also try cleaning your boost solenoid, by connecting the two spare green plugs together under the steering column with your ignition on. The ecu will then actuate the solenoid constantly for a couple of seconds to clear any blockages within the solenoid.

 

is the boost solenoid suposed to click constantly all the time? I looked at my mate 94 wrx his is constantly clicking mine doesn't??

 

shouldn't click all the time only when the throttle is cracked open
if his clicks all the time either hist throttle pot needs adjusting of he is running a chipped ECU.
Some of the chipped ECU cause this due to the boost control map settings.

 

Found a kinked fuel line test in the morning see what happens.

 

Take a look inside the ECU as suggested. See if you have an extra chip.

 

theres that photo again ...

as said have a wee look in you ecu for a jap/strange chip it will only take ya 5min

 

a restricted exhaust i.e. disintegrating cat will cause boost probs too.

 

Damn straight

 

Problem still there but intermitent now, i tried to remove the ECU cover and the screws are so tight two rounded and i cant get um out at the mo.It all looks original with a plastic cover and the bolts dont look like they have ever been touched. On shift for a few days so will have to leave it for now

 

The brass screws will be held in with lots of locktight. They'll come out with pliers if you have rounded them.

The ECU should have a metal case as above, not a plastic cover!

 

had a plastic cover over the metal case.

 

if the screws won't come out chance are it's a virgin

 

it's tight!

 

no high boost at all today 0.4 bar, i offically give up! would some sort of boost control system bleed valve etc make a difference?

 

tbh if you do that you're just hidding the problem.

Have you checked all the hoses and fittings?
Possibly the actuator playing up?

 

Could be but it holds 1bar sometimes no problem. if it was stuck i would get high boost all the time if it was knackered i would get no high boost at all. all the pipes been off and cleaned.

Is there any good garages in the cardiff area ???? anyone used hyeline?

 

If the actuator is loose you will get variable boost,my mate's 94 wrx has had a similar problem (not as extreme though) to you.

 

I might adjust the boost right down on the actuator,reset the ECU and gradually adjust it up see what happens. If that don't work its off to a garage!

 

Avoid hyline like the plague, I had 2 bad experiences with them....

ACE motorsport (just past Caerphilly way), are suposed to be very good..

 

Have u changed plugs and checked coil packs for cracks under rubber ends

 

new pugs last w/end and coil packs checked then, there ok.