I bought a MY93 WRX over the weekend, running a Scoobysport full system (de-catted) and HKS induction kit. Driving home I noticed a couple of little hesistations, and one big one when I floored it in 3rd or 4th at about 4000rpm. Other than that I was really happy.

Tonight coming home from work taking the scenice route, after a good few miles of slow speed running, followed by a few flat out runs through the lower gears, it started to stutter quite badly under full throttle/high boost, so I slowed down for a few miles and it seemed to clear again.

I don't think the engine is pinking (using Optimax, no octane booster) but I can't hear much over the exhaust! It just suddenly stops making power then it comes back in. It does backfire occasionally and "burble" a lot on the over-run, but I thought they all did that.

What things should I check in order from simple through to "omigod"?

TIA

 

Overboost? Is there a boost gauge?

 

Oh My God
You are basically describing the symptoms of my car!!!!
Going in to PE on saturday to sort it....
plus get loadsa power too lol
Rob

 

p.s. if i floor it from 2000rpm it pulls to about 4100 then the power drops and then it comes back on a bit at about 5000rpm....
then again, it dont do it all the time, just most of the time !!!
BUT, all better on sat i hope!!
Rob

 

My first thought was overboost. Actually, thats a lie, my first thought was "Oh ****, I've killed it", followed by "overboost?"

There's no boost gauge. Where can I get a cheap one, and where do you plumb them in?

If it is overboost, how do I cure it?

Cheers

[Edited by NotoriousREV - 5/20/2002 8:27:38 PM]

 

clean the wastegate solenoid and pipe

if fails consider if the restrictors need changing.

cheap boost gauges are about £30 and at least you will get an idea of what it is doing even if there is a 1 PSI offset on the gauge like mine (but then the expensive ones are often out - only a guide).

 

OK, sounds easy, but as this is my first turbo car, which bit is the wastegate solenoid and which pipe?

Is is the little gold canister above the turbo with the arm and spring sticking out of it?

Sorry for the dumb questions

 

could it be sh*te getting in through the induction kit and causing the MAF to hiccup?

simon

 

It might be your ECU dying . When I went to Power Engineering a couple of months ago with my hesitating MY93 WRX I was getting retardation of approximately -11 degrees and 225BHP. They replaced the ECU with a special one Mervyn has been working on, and I now get no retardation at all, a MUCH smoother power curve, and 256BHP . Mervyn mentioned that he had seen a number of MY93 and MY94 WRXs with the same problem - they all seem to be going at the same time

Cost was £400 plus VAT for chip, plus rolling road diagnostics (£75 + VAT iirc) - not cheap but definately worth it!

Daniel
MY93 WRX

[Edited by ScoobyDan - 5/21/2002 2:10:22 PM]

 

Hmm. Could be simpler than that. The same thing sorta happened to me last week. It seems that there was a hole in the big hose that comes round from the inlet manifold to the air box. But it was actually at lower revs that I felt it most as I'm trying to boot it. Will sort it out by this saturday. All I've done is wraped it around with a hose repair kit. Seems to work for now...

edit~ I too have an MY93 WRX.

[Edited by Katana - 5/21/2002 3:15:46 PM]

 

i believe you will need to adjust the fueling
get an APEXi SAFC and you will be sorted

 

This sounds like a classic description of over boost.

You need to clean out the wastegate solenoid, the manifold pressure sensor and the pipework feeding them with aerosol brake cleaner.

To clean the wastegate solenoid, connect the 2 black and two green plugs under the dash, by the steering column. This will then cycle the solenoid, washing through your cleaning agent that you squirt down the pipework.

[Edited by Pete Croney - 5/21/2002 4:01:04 PM]

 

http://www.sidc.co.uk/faq.htm if the above link does not work for you.

AFC will not help if it is not a fuelling problem.

Sorry Pete edited - was just posting a working SIDC FAQ address as the one he provided did not work on my browser.

[Edited by john banks - 5/21/2002 4:03:32 PM]

 

Thanks John

The fuel one got me too. I love this BBS

 

I have had this problem too, restricts me to 0.5 of a bar in 5th gear when flooring it. The 1993 WRX does not come with dump valve as stand though boys. To sure my problem, i replaced the spark plugs and oil filter, then filled it wil a good old load of 100Ron petrol and that seemed to sort it out.

 

Michael

Who told you that the 93 does not have a dump valve?

 

Um, it does have a dump valve. I can take some piccies if you want. Its the round plastic thingy in between your intercooler and airbox(assuming you still use it )

 

Thanks for all the replies, you guys rock! I'll let you know how it goes