I had a major problem last night that I've had to a less major degree before and always put down to fuel cut/overboost.

Basically, in the morning the car was running 100% perfect, pulling like a train etc.

After work, returning home, got onto the local dual carriageway, gave it some welly and it felt a bit "wooly",not pulling as much as normal. I get this quite often. When the road cleared a bit, I floored it to get up to cruising speed. It definately wasn't pulling well and at about 5500rpm there was a backfire and the rev counter needle dropped to 0 and I'd lost all power. After about 5 seconds it came back. The car ran OK afterwards, still didn't want to pull, but wasn't missing or anything. It felt like the only difference between 50% throttle and 100% throttle was volume of the induction/exhaust but no real acceleration even though the turbo was spooling up (boost guage currently disconnected so no idea if it was actually boosting or not).

After I got home and let the car stand for 10 mins, restarted it and it ran fine again.

Like I say, I get this quite often, but it's normally only a hiccup, not 5 seconds with no power.

Any ideas/offers of help/free new engines gratefully recieved ;)

It doesn't throw a CEL when this happens? What mods are you running?

If it doesn't normally pop / backfire then the fact it did this time suggests an ignition or related eletrical problem -- unburnt fuel getting into the hot exhaust and igniting. This could either be a cause or a symptom ...

Sounds like it could be a dicky connection ... especially as the revcounter dropped to zero. Did the engine actually stop running?

[Edited by brickboy - 3/13/2003 1:07:21 PM]

No lights came on at all. Engine was still turning over as the car was in gear and rolling, but pressing the accelerator produced nothing.

The car does pop quite a bit (full Scoobysport system from turbo back) and has an HKS induction kit.

I thought about bad earth, but I don't have any other electrical problems.

I'd also filled up with Optimax 2 mins earlier (from 1/4 tank up to full),could this have caused a problem?

When I normally get the problem, the car runs better than ever before it does it, then starts to get wooly, followed by the pop (that lasted 5 secs last night) then carries on running a bit flat.

Curious that the tacho dropped to zero -- does it run off the ignition, rather than a cable drive from somewhere? That could be a clue.

Anyone else know?

were you in 2nd holding say 3500 for a while b4 pressing the loud pedal?

When my car did this it turned out to be a dry joint on the ECU board. Took ages to find it, but thanks to the skills of Merv and Co. at Power Engineering it was resolved.
Your symptoms describe what happened exactly as I remember it. The speedo dropping to 0 is the bit that makes me think you may have the same problem.

Thanks for the replies.

Just to add some info, it seems to be doing this just after a fuel up (I use 2 different Shell garages). I usually fill the tank from around about 1/4on the gauge. Maybe the ECU is not reacting to the differences in the fuel quickly enough?

How can I read the error codes from an early ECU?

When I bought Mine (97 UK Turbo), the guy before me had run 2 tanks of normal 95 unleaded to 1 tank of optimax.
A friend advised me to run permenantly on optimax, so a run a few tanks through her then filled up and disconnected the battery for a couple of hours, apparently this clears the data on the ECU. Then connected it back up and the ECU is supposed to re-map itself to the fuel you are using..
Is this correct anyone or have I been lied to?? Not all that clued up with the technical jargon..

NotoriousREV,

can I hazard a guess that the car is an earlier car? Can I also hazard a guess that when you the rev counter falls down to zero, the rest of the dashboard is still operational ? If so, take it to your local Scooby garage and get them to swap out your coil packs to see if that helps. The loss of the rev counter can be caused by a serious misfire, if the revs do not rise with the foot to the floor the ECU figures there's summat not quite right and shuts down for a few seconds and the fires up again; during the down-time it doesn't drive the rev counter.

Cheers,

Pat.

Thanks Pat! Yep, you hit the nail on the head,although the car is a WRX so my local Subaru dealer is a no-no ;)

I was beginning to think it was either plugs or coils breaking down under load. Hopefully a plug change this weekend, renew/add earth straps and I have some Bosch MEC723 coils coming from Aus. If it doesn't cure the problem, it certainly won't make it any worse.

Oh well, it definately wasn't the plugs (although changing them did make a difference to overall running).

Had the same huge power loss again, this time I noticed that I only lose power in 4th gear and the power only comes back on if I change gear :confused:

Is there a gear position sensor on the Scooby ECU that could be playing up?