This has just happened to me today.

I was driving along the motorway steady about 75ish and the car lost power for a split second. There was no cel light. It did it a couple more times so i slowed and got off at the next exit (i was nearly home at this point). Driving then became difficult, pulling away from rest gave the same stutter now and again. I got home ok by driving as gently as possible.

When i was home, reving the engine gave a similar stutter in the delivery. So i checked the ecu fault codes. No new codes.

Then a strange thing happened (which i've never had before), as the engine was idling, it just stopped (no hunting or anything, it just stopped as if the ignition key was turned off). It restarted normally settled into its normal idle and then stopped again. I tried a couple of more times with the same results.

If it's reved it will stay on. and it will drive.

What do you think? Is it the usual suspects i.e. MAF, lambda??

Car is a version 2 STi Ra, with standard ecu and minor mods.

 

Any thoughts??

I've had a bit of a search and i can't find any other threads about the car stalling when the idle quality has been normal. It just stalls like the key has been turned off. Very strange.

 

Sounds like a similar problem I had. Hesitation/misfire off boost, fine when booting it. Also no CEL light. Try changing the lambda.. I got a universal one from a motor factors.. about £40, chopped off the old connector and hey presto.. You may want to find how much Subaru charge first. I only got a cheapy 'cos it was convienient.

Doesn't a duff MAF affect tick over?

 

Thanks for the reply.

I did an ecu reset today, and as i started it up in the middle of the procedure, it fired normally with no cel flashing then it stalled. I started it again and the cel started flashing the code for the MAF sensor (23).

So i will replace this. I think i will also replace the lambda as it doesn't cost all that much.

Also earlier in the day the car was idling ok and i tried the MAF test (unpluging it while the engine is running). The car stalled almost instantly, which usually means it's ok (i know it's not a definitive test). So there you go.