MickyC

Evening,

Bought a postal map for my 99V impreza turbo.

Arrived no problems, fitted no problems, started car no problems, drove car revs keep dipping and then raising all the time.

I then took the car out for a serious run, got up to some serious speed, love the new acceleration etc etc but pulled off onto slip road, stopped at stop sign, engine cut out immediately, didn't even idle, re-started her, up to next roundabout driving sensibly, engine cuts out again when revs drop, re-started her, drove the 300 yds to my house, slowed down to turn into drive, engine cut out.

Eventually managed to get the car to idle after being stationary for 5 minutes, but very eratic.

Love the extra power, dont love the fact my car is almost undriveable at the moment!

Any ideas lads?

ps the boost gauge peaked at 1.38 bar!!!!! Is this to high?

Thanks

Micky

john banks

Micky as per my email to you (sorry out this evening) there are two problems you've uncovered.

Your car was overboosting as standard to 1.08 bar and now overboosts to 1.38 bar. For the postal map to work the standard boost should be behaving properly, and 1.08 bar is overboosting. The car is supposed to run 0.95 bar as standard, and on the remap up to 1.25 bar. Whilst the Blitz turbo timer does pick up some spikes rather more than a normal boost gauge, your car is still running too much boost. There are a three ways to solve it: 1. loosen actuator by half a turn at a time until it peaks no higher than 0.95 bar standard or 1.25 bar on the performance ECU. 2. Drill out the 1.2mm restrictor to 1.25 and then 1.30 mm to stop the overboost (this is fiddly and imprecise, acutator method can work better). 3. bring the car to me and I will tweak the map at no charge to sort the overboost with the ECU or do either of the above. For your trouble I will also do a custom map at no charge to make it worth your trip if you choose to do this.

The idle problem is almost certainly the lambda sensor or MAF sensor. The original ECU can adapt around a failing sensor and when you reset the ECU or swap to a performance one (effectively the same thing) then the idle goes off. I suspect if you put the standard ECU back in now it will do the same. The resetting has uncovered a problem. The performance ECU uses standard Subaru idle setup so it is invariably something else to blame.

It may seem to be weedling out to blame the two problems on your car, but I am happy to see your car at no charge and sort it out or immediately refund you. However, you will be left with both issues on the standard ECU to sort out also, although a 1.08 bar overboost is acceptable, with a postal map you have to work from a common baseline, most cars produce 1.15 - 1.20 bar which is ideal.

Dark Blue Mark

John, sound familiar

Micky, I had the same problem and John helped me out a great deal. I have no doubt (almost) that your MAF is shot. I fitted mY tek2.5, idle went all over, put the old one in thinking it was the ecu. Same problem. Your ECU learns to cope with the MAF being buggered, and when you remove it, it resets the learning.

Very much doubt its the ECU. Ring Power Engineering for a new MAF element £80? Problem solved.

MB



[Edited by Dark Blue Mark - 5/23/2003 11:33:49 PM]

john banks

Yes Mark, Mike a few weeks ago also had the same issue - think his was the lambda in the end with his. All sorted now. Lambda was dodgy with two custom maps I did too - one messed up the idle, the other scared me into thinking it was a bit too lean.

MickyC

Thanks John & Co,

I will be sorting a new MAF sensor week after next, and I look forward to driving my car again.

I am booked in at Revolution in Gateshead to get it looked at.

A quick question, when i bought my car 2 months ago the only mod it had as standard was the Magnex 6 x 4 backbox, i have since given the car the full decat treatment, and fitted a blitz dual turbo timer, and then of course the ECUTEK 2. i bought a two year "gold" warrranty which basically covers everything but disks, pads, tyres etc etc, if i take the car back to the garage i bought it from saying that the MAF sensor has gone will they replace it if they suss out the work i have had done (i dont think it should be so bad as i get on really well with the aftersales manager). I suppose they would never check to see if the ECU had been changed?, even if they did i suppose i could say "thats the one you supplied with the car"? what about the exhaust though, if they see i have fitted a decat exhaust, would this give them an opportunity to say sorry your warranty is null and void?

Thanks

Michael

mega_stream

Depends where you bought it I guess, I used to get work done under warranty on MY99 UK car at the main dealer with TEK2.5, and full decat. Inc lamba sensor, MAF, Idle CV, clutch, brakes...

The good things about these maps is that when plugged into the monitor they show up as the original ECU, it's just the coding that's changed.

My car also suffered big overboost at times, now owned by Lan-Man he posted a 1.5 bar boost peak up the other week

MickyC

That sounds promising then!

I used to own a Volvo 850 T5 which we eventually got running at just under 280bhp, but I was always worried when I took it into the main delaer for servicing that they would somehow re-set the ecu (or something along those lines) will the subaru main dealer definately not attempt to either re-programme the ecu, flash it, or whatever you call it?

Also I am interested in how to the diagnostic software all it sees is a standard ECU, how do you manage to cloak it so to speak?

Thanks guys

Michael

john banks

Subaru dealers cannot program ECUs. Resetting it will not erase the new maps. It is not cloaked, it is just that the Select Monitor cannot read more than basic ECU information.

DemonDave

iTrader: (13)

Just to add to the current info.

I have got Marks tek2.5 now with no issues (apart from enjoying it to0 much)

I have a new clutch fitted, had the same problem with the idle.

New MAF sensor and housing under warrenty and everthing back to normal.

Dave.

Dark Blue Mark

Hi Dave,

Glad its working as promised!

Its amazing how many peoples MAF sensors seem to be shot, and how many pick up on it when fitting a TEK2.

John, when the standard ECU learns to cope with MAF failure, does it do it gradually? I guess im asking whether the MAF degrades, or just fails suddenly?

If most never notice it dying, because the ECU is adjusting - it might be prudent to reset every 6 months or so?

MB

john banks

I think changing the MAF sensor is Merv's favourite mod - as it is cheap and improves an affected car no end!

You can tell from experimenting that the ECU learns and adapts an idle over time, although I have no access to the tables it uses, something is going on.

Resetting the ECU would not pick up every failed MAF sensor.

I suspect the lambda sensor because that is probably the main input into the learned idle? Hence when it goes the ECU may continue with old settings. Reset it and it is all over the place.

Dark Blue Mark

This can be checked by unplugging the lambda right John? If idle stays dodgy its the MAF, if its ok, then its the lambda?

Or am I being a dumb ****?!

MB

john banks

Normally I just plug in Delta Dash, so haven't worked out a scheme with unplugging various sensors. However, my car idles better with the MAF unplugged even though my MAF is good. It might be my APS induction kit, which is why I am going to retry a 57i and also try my box for conversion to MAP only. A lot of cars will idle open loop (lambda unplugged) quite well - quite rich though and I've found if I map it like this the values vary from day to day quite a lot, so running with the lambda is better.

MickyC

John,

Installed new MAF sensor, problem solved.

Re-installed your ecu, no problems at all.

Max boost I am getting is 1.15 peeks at about 1.2.

Is this about right for the current warm weather conditions?

Thanks for all your help and for bearing with me until things were sorted, I appreciate it.

I will send my ECU to you so that you have it certainly before Friday. (more than likely be Thursday)

Can I just say that this website has such a massive strength in depth of true subaru knowledge that it puts the supposed subaru dealers to shame. I genuinely appreciate all the help and guidance I have received as I am about as technical as a peice of medium sliced white bread!

£500 spent with Mr Banks is £500 well spent!

Michael

Brun

Don't say stuff like that
I've got £500 saved up for next months insurance