B4 Boy

Was doing a bit of work today and had to disconnect battery.
Connected the battery again and took the car out and the car started lurching...

Between 2,500rpm and 3,500rpm on the 1st turbo
and anything above 5,000rpm on the 2nd

And it was bad!!! Managed to drive home albeit at slow speed but now have no idea where to start... Anyone?


MY99 B4 Legacy (STI ver 5)

john banks

No experience of this model but there is a yahoo group if you search for it.

Also this covers the twin turbo and diagnosis:

http://www.ravensblade-impreza.com/m...agnosisegi.pdf

B4 Boy

Thanks... Am a member of the group but no joy yet. Will keep searching!! Anyone?

David_Wallis

What work were you doing, Have you disturbed any hoses??

David

B4 Boy

No I was replacing an earth wire, I checked the hoses all seem ok. Reading up on a couple of other topics I'm starting to think it may be the MAF Sensor... Need to do some more checks.

pwebb

as above, my money would be on you having disturbed something like a plug lead or maybe the earth wire itself is not contacting properly - worth having a look at night to check nothing is arc-ing.

if not electrical then most likely fuelling...

after such a reset the engine will be 'lumpy' for first half mile as the ecu re-learns - once key is removed and engine re-started it should be fine though.

on another tack
what fuel are you using? - if you use regular 95 ron and you reset the ecu then it will take a while to retard enough to use the crap fuel - better to stick with optimax - particularly after an ecu reset - the b4 likes 98 ron +

Paul W

B4 Boy

Believe me I have checked and re-checked!! I replaced the negative battery terminal as part of the work could it be that there isnt a good enough contact? I have checked it and it seems ok.

As for fuel, always Optimax, admittedly didnt drive it for longer than about 1/4 of a mile so maybe didnt give the ECU a chance to configure could that be the prob?

pwebb

hmmm - 1/4 mile - if this was from sold start then the ecu will still have been in its closed loop cold-start mode - ie using hard coded maps not learning from the sensors... I would wait till engine warm (maybe do this at idle if you are worried) then go for short run using all the gears (preferably with the a/c off) - then stop + completely remove ignition key + re-start - should be running fine after that despite memory being cleared.
NB - manual says to turn key to 'acc' position for 3 whole seconds before attempting to start immediately after a memory reset - I have tried starting without waiting and it coughs + splutters

good luck - Paul W

B4 Boy

Ok, Ill try that and let you know how i get on... Thanks

submannz

Did you complete the ECU reset? You must do the reset from dead cold engine then start don't touch anything let run until the fans come on turn the car off . Turn the car back on and take for a drive.

I had a similar problem on my car for no reason, the reset may just have been a fluke. What I did was while driving the car switched it off and back on again and the problem went away and never came back, no ecu error codes or anything.

All Subaru's have crap earthing you could look at running a couple of extra earths one each from the engine and chasis to the battery.

B4 Boy

I did everything to the letter and still the same problem, it seemed to get better in the low gears and then the second the revs crept up it spluttered again.... Will call Scoobysport this morning they're only round the corner see if they can help!!

Thankyou all for your help.

B4 Boy

I spoke to Scoobysport they suggested running the car through a whole tank of petrol to allow the ECU to adjust does this sound right? If so whilst its running like a bag of spanners do I take the opurtunity to add some extra earths to the engine from the Neg terminal on the battery?