my 94 wrx has developed a rough idle and a hesitation when under light throttle ive changed all 4 coils re-gapped new plugs to 0.7 as told by powerstation could this be an air flow meter problem , i have heard about oil build up on the air flow sensor from the k+n filter causing this , or would it be my bailey dump valve not sealing , or is it some thing more expensive / serios ?

any coments greatly welcomed / needed

cheers
Matt.

 

I had a ramair filter and the gunge got on the MAF sensor. Made the car a bit sick for a while.

In the end I cleaned the MAF VERY CAREFULLY (Not at point blank range...) with some spray brake cleaner. It seemed to do the trick. Be careful, as MAFs are fragile and expensive. However, if you may be looking at a new one, you don't have a lot to lose...

I have a UK MY96, so it should be the same sort of MAF as yours. Don't try to clean the sensor if it's not one of the hot wire ones!

[Edited by dnb - 1/25/2003 11:16:00 PM]

 

Webster, I have a sneeking suspicion that we have the exact same fault with our 94 WRXs at the moment. I'll be paying close attention to this thread

 

any one else had this problem a? and bttt

 

Webster,

I had a go at tracking down the prob on my car today. I cleaned the MAF and the boost solenoid, refitted all the induction pipework and checked the coils.

I did notice that the end of one of the coils was cracked (coil nearest the turbo). I pulled back the rubber hood and the end of the coil fell apart in my hand. I bodged it back together to do until i get a replacement.

I took the car for a 10 miles drive and it seemed fine. The stutter at low load wasn't there. I made a point of staying at low revs the whole time in an effort to cause the stutter. Nothing.... not even a misfire from the gubbed coil.

I am now truly baffled. It'll get a true test in the morning when the car is cold and damp. I'll let you know how i get on.

 

I have the same prob on my 93WRX guy's, i have replaced the plugs and re-gapped them to 0.7 but it made no diffrence, infact it made it worse, which model plug have you two used...i used the NGK 6b's, do you recon 7b's are better..

Cheers,

John.

 

I also have the same problem..

Guess what .... 94WRX.

Defo a sensor thing I feel. I have changed the MAF - Because I have a HKS cone filter that lets the crap in.

But it is still no better. Will get someone to look at coils, lamba etc. Will post - If I get to the bottom of it.

I am also looking at this thread with interest to see if anyone solves it.
Good luck guys
Steve

 

My girlfriend who drives the car every day said it did not do it at all yesterday or today, i'm thinking it's either the gunked up maf sensor or the sticking dump valve .
I have also booked it into a local import performance specialist next friday for a check to see if they can get to the bottom of it if they do i'll let you all know.
p.s i have already fitted new,coils x4, new plugs , and gapped them to .7 and after inspection my original coils were perfect no cracks at all (what a waste of £274.00) but at least i know the coils were'nt the cause of the problem

 

Well that's the last 2 cold wet mornings and about 60 miles and my car seems fine now. No misfire or spluttering first when cold and no erratic idle.

Not sure if it was my dodgy coil repair, cleaning the MAF or cleaning and refitting the pipework that sorted it but one of them has made a big difference. My money is on cleaning the MAF.

 

Well after a few months of having this problem.
Guess what? ... it has stopped.

About a week and a half ago my airflow sensor and HKS filter were replaced with identical items.

Noticed lots of dirt that the crap HKS aftermarket filter had let through.

However this did not solve the problem.

But took the car for a very hard drive this weekend at the local meet and this seems to have cleared the problem up. cleared the crap out as it were.

Wierd. But those are my findings.
Best wishes
Steve

 

My UK97 has had this (occasional stutter/almost stall when crawling in traffic) since fitting a few tuning mods including a ramair filter.

A few months later and I inspected the MAF and found an oily film over the internals of the whole assembly. Cleaning it gave a temporary improvement but it soon came back.

Have now changed back to paper element and it seems a lot better although I still get the very occasional dip in revs when crawling at idle.

I going to give the MAF another clean soon and hopefully this will be the end of it.

What air filters are you wrx owners running?

 

Standard paper filter on my car. Thats now 4 days since cleaning the MAF and still no sign of the stutter returning. Car has been running great since.

 

I'm running a HKS Mushroom filter on my WRX...

 

K+N cone filter it's been on there for 6 months but the fault only started 2 weeks ago but has now stopped, the car has been running fine now for 4 days

 

HKS Mushroom at the mo.

Question. What is the best replacement filter?

I take it that it will be a panel filter, so the MAF dosen't get dirty. Is there an aftermarket filter that is recognised as being very good for induction but that is reliable (won't let dirt in)?

Best wishes
Steve

 

My legacy is struggling to idle sometimes. I read about cleaning MAF.
1, Can i on legacy Turbo ?

2, If so how ?

3, And with What ?

Please any advice on this subject as wifey is doing my head in with it when she does school run

Hope u guys can help please ?

Steve

 

Well thats the bloody hesitation back on my car after a week of running fine

noticed a slight stutter yesterday and by this afternoon it was playing up all the time. Thing is though... it came back RIGHT AFTER a good long run on the motoway

Typical... advertised it for sale on Monday since it was finally running 100% and got someone coming to look at it tomorrow and it starts stuttering again. Looks like i'll be out with the carb cleaner again tomorrow.

 

Well i cleaned the MAF again but the stutter is still there at low revs.

The fact that the stutter cleared up for a week leads me to believe it is definitely caused by something i was tampering with just before it cleared. Looks like a new coil is on the cards now.