Help!!!!

I've just baught my first impreza ( 95 WRX jap import ) i've had it for about 2 months and all has been fine until now. Every time i give it some of what it wants it seams to cut out or missfire on boost and its really doing my head in. I have no real idea where to be looking for the fault, i was hoping it would just be the old coil packs so replaced all of them but its still doing it.

Hope some of you guys can help me out as i dont fancy a main dealer ripping me of

 

MAF?

 

fuel cut maybe?

bets bet get it to a specialist to have a look at, where abouts in the uk ar eyou?

 

Ye supose it could be the MAF. would be just my luck after forkin out £150 on coil packs, i was soooo hoping that would cure it.

I'm in leeds/Bradford Tidgy,not sure if theres any specialists near here tho?

 

Scooby Clinic | The UK's Largest Independent Subaru Specialists | 01246 590 807 - Chesterfield S42 6QX is down the m1 from you

 

great stuff cheers for that, will give them a call when i get a min

I really hope its nothing major

 

might just be an ecu rest is required

 

How much boost are you running when it cuts out?

 

"might just be an ecu rest is required"
how do you do that then? is it just a case of disconeting the battery and pumping the brake peddle to discharge the system or do u mess with the conectors under the steering wheel? or is there more to it than that??

"How much boost are you running when it cuts out"
Well i've not messed with the boost so it should be what ever stock boost is? but if it helps at all i fitted a baily twin piston? dump valve and its only miss behaving when the accelorators nailed to the floor at about 3500 rpm upwards

 

Do you not have a boost gauge then?

I'm asking to eliminate the Fuel cut someone mentioned.
I know you said you haven't touched the boost, but that doesn't mean it would be standard, as its a 95 WRX, its very likely someone has messed with the boost in its life. But, as you said you've had it 2 months, and its been fine before, its not likely to be Fuel Cut, unless you've never driven it hard in the first 2 months.

 

my 95sti was missing under boost as well,a set of new plugs gapped properly cured it.i was expecting coilpack as well

 

yes sorry its got a boost gauge but its one of those silly little Lamco 42mm ones thats been fitted below the stereo and is a bit tricky to look at.

I've driven it hard most of the time really but never too hard if you know what i mean. the only reason i noticed there was this fault was when i tried keeping up with an STI but at about 100 mph in 5th gear the car started jerking and felt like it was missing

 

Oh i wonder if it could be the plugs then as i serviced it a couple of weeks ago?

 

If you changed the plugs were they gapped correctly?

 

what plugs have you put in?

they should be PFR7B or PFR6B NGK's

 

erm well I never really bothered to check what the gaps were or what type they were, I just asked for a set of plugt to suit a 95 WRX ooppps.
So its probably a good idea to whip em out and check type and set the gaps. Does anyone know the gap size? is it 0.007"

 

on my 93wrx i use PFR6B with a 0.7mm gap

 

right i ho then i will have a look at the gaps an set em to 0.7mm, thought it was a bit small when someone told me it was 0.007" lol

 

My saloon still has this problem although i havent traced it yet, i've tried coils and plugs but still occuring, i've been told fuel cut or wastegate actuator but im still not sure. Its 341 and mid mods but it was bought in this condition and although there's plenty of paperwork i cant really trace what im supposed to be looking at. Whats more, the ecu isnt registering a fault. Plenty of power, oil pres and performance but at around 4500-5000rpm for less than a second, a total cut in boost and then power again.

 

Slowboy-racing uk

speak to neil at slow boy racing. one of the best in the business.

 

i have a 97 wrx and big prob i had was using s**t fuel.if urs is a import make sure u use v power or bp high octane because imports run crap off standard fuel.uk models r fine because there designed to take standard ron fuel.my car was jerky and didnt boost fully. i use this all the time and it runs like a monster.my car only used boosted to 0.6, now at 1.0 and such a difference.if not that more than likely ur actuator needs checking.

 

Not sure if its the fuel as all its ever had is high octane stuff from BP or Total.
But i've just taken it for a spin round the block an noticed its only boosting to
0.5 MPa now where as it used to be up at 0.9MPa ( Dont know why its in MPa and not in P.S.I.)
Theres also a solenoid or something clicking like mad for a couple of seconds when i turn the ignition on, dont know if its ment to do that?

 

just cleaned everything with the good old brake cleaner which seams to have got it running a bit better and re checked the fault codes, and hey presto its show a MAF fault (code 23 ).
So does anyone know where to get 1 cheep as poss?

 

for the early models there isn't a cheap MAf iirc but try DEALERS FOR SUBARU AND ISUZU IN SURREY CHEAM New + used cars.

My maf (93wrx) was about £200

You could always try to clean it but i don't know if it will do any good.

 

mine jerks and misses very slightly at 112mph due to limiter on it. dose your car keep speeding up when it starts to miss fire at that speed or do you know for sure it has no limiter, just a thought

 

well it starts jerking near the top end of the rev range but it is more noticable in 5th gear, im assuming this is due to not having another gear to change up into.
The car has been de limited when it had the speedo converter fitted i think?
I tried cleaning alsorts on it on friday which has improved things a lot but its still not coming upto full boost

 

at top of rev range when all power is needed may be fuel starvation related i.e weak fuel pump or slight blockage in fillter.

 

heres a thing thats free and easy....and also very common.... clean out the boost solenoid on the drivers strut turret..and the hoses to the turbo etc.. oil residue ... a couple of my cars have had it and will cut boost when planted in higher gears...costs pennies to check with carb cleaner ..be sure to blow clear when done...connect green connectors under dash first as this activates the solenoid....htere is a how to on here somewhere....

 

Cleaned everything on friday with the old brake cleaner which has helped a bit but it still cuts out or splutters in 5th at high RPM. ecu check is still saying the MAF is playing up so have sourced 1 of flebay.Will wait and see what that does