ScottyDoo

hi, new to this site... and new to scoobs in general!
i bought an impreza turbo estate from reading and drove it back no problems until i got about 20 miles from home and stopped to get fuel then i had the check engine light flash on so i stopped then it turned off... carried on back and for the next 2-3 days kept flashing up intermittently.

the boost was playing up over the next few days but still worked..
then tuesday evening i went to boost up and it was like i hit a brick wall and the car kept kangarooing down the road and died... i turned it off and started it again but now it wont let me boost up, just splutters when you get over 3000rpm.

ive been told it was the boost solenoid so i replaced that and i did an internal diagnosis and was showing up as codes 23,22,44 and 45.

now ive reset the ecu last night the old fashioned way by disconnecting the neg terminal all night and turned it on today to do a check and success! no codes just the continual flashing check engine light which means no codes! yes? but when i started the car boom. the check engine light is on all the time again! and the code its flashing up with is the 23 one - 'mass air flow sensor circuit'

could this be totally throwing everything out??? im at a loss here. ive spent all out on this car and cant afford anything else to chuck at it....

any help is greatly appreciated!

im thinking next if anyone is local to me i could try their MAF in my car and see if that cures it? ill pay of course!

thanks guys,
Scott

ScottyDoo

nobody want to help me out here then???

ScottyDoo

had a fiddle all morning and been up and down the road, now ive got the code 22 again: knock sensor fault. whats the best course of action on this? buy a new maf sensor and see if that solves it?? if not then a knock sensorm too or just buy both and save the risk?? also whats best to go for? im skint, so all out on a genuine subaru maf sensor or will the aftermarket ones off ebay do the job? as long as the part numbers match? and whats the difference between the ones with the green rubber band on and not? i need to get it running sweet before i have to do a 4 and a half hour journey to preston at the end of the month! cheers!

FMJ

iTrader: (2)

If you are skint then usually a used Impreza with fault codes is a bad place to be... I would get a genuine Subaru MAF. You will need one at some point anyway even if it doesn't solve the problem. Luckily the knock sensor is cheaper.

The ebay ones are hit and miss but if you get one and its still giving you problems you wont know if it was still the MAF and you just brought a crap one...

ScottyDoo

update on this:
ive replaced the maf sensor twice, first with a cheapy off ebay, worked fine for about 5 miles, with the boost working and everything. now ive got a lumpy idle.
replaced the cheapy off ebay with a second hand unit from a breakers but it still lumpy on idle! dips from 1000 to 0 with the engine almost dying! and when im coming up to junctions ive got to keep the revs up or it dies 80% of the time! now ive been told it could be the idle air control valve, which i took out and cleaned as it was gunked right up with black crap, cleaned and refitted that which sorted it for a couple hours, which by that i mean the idle was sitting at 1100 rpm quite nicely after a steady cruise up and down the A303 by about 5 miles each way... turned the car off and left it for half an hour and boom. problems back again.
now when i take the vacuum blanking plucg off the inlet manifold it runs fine, but as soon as i put it back on it really struggles for air and dies. does this mean anything? im reaching the end of my knowledge here!! please can someone shed any light on this?! thanks in advance!

DmcL

first thing to do with MAF related issues is check the MAF sensor and make sure its clean. give it a blast of carb cleaner, let it dry and see if it makes a difference. 9 times out of 10 MAF problems are simply a dirty sensor.

ScottyDoo

hi DmcL, i cleaned it up with electrical contact cleaner when i got it as it looked a bit sooty from the previous air filter housing it was in... but it boosts fine now whereas before it wouldnt, and with both the cheap one off ebay and the second hand genuine part they're both giving the same problem : lumpy irregular idle.... i just dont get it....

ScottyDoo

oh and no codes showing on the internal diagnosis....

DmcL

second hand unit may have been faulty or perhaps a different part number sensor, ebay cheapie is a clone/pattern part so might not be 100% exact in measurement supplied to the ECU vs the correct OEM sensor.