Haven't gotten around to fitting it yet - been busy trying to buy a house! Will do it tomorrow and post back on here once it's in and I've been for a drive...

 

Hi, I have a 2001 Bugeye which I bought 8 months ago and had the same problem as you. The car had a 3" cat-back exhaust, BOV and cat-less down-pipe but had not been remapped. It was running flat and, after discussing the problems with local WRX 'experts' I went for a ECUTek remap and cold air intake with K+N filter. The car goes well now but occaisionally runs flat again. I used to think that the performance drop was due to high ambient air temperatures (it gets pretty warm down here in Brisbane) but sometimes it would run well on hot afternoons???
It also pops/backfires occaisionally when changing up through the box which made me think that the MAF was suffering some sort of intermittent failure.

I changed the MAF for a 'used but good' replacement but it hasn't really made a difference, now, after reading your thread, I'm wondering if the the ECU is detecting detonation due to dodgy low octane fuel -( I only use V-Power but there have been cases of unscrupulous garages selling low octane fuel as Premium grade). The car is running flat at the moment and I'm wondering if it's worth disconnecting the battery to see if it makes a difference.

It'll be interesting to see if either of us manage to eliminate this problem.

 

that instantly says leaking BOV to me..

Simon

 

I'd go with Simon's suggestion - he does after all have plenty of experience to draw from! Nothing to do with low octane fuel for me. I've been running on V-Power or Tesco 99 since I had the car unless I can't find it when I'm running on empty - at any rate, always use super....

 

I also went along with the leaky BOV idea too and changed the aftermarket bov for a new GFB hydrid unit prior to the remap and other work..... It didn't make any difference despite setting it as plumb-back/vent to atmosphere/hybrid. I've altered the spring adjustment too but, as before, there is no change.

The vast majority of fuel sold down here is 95 octane but every garage has a premium 98 octane grade too and some Shell garages sell V-Power racing (100 octane) as well as V-Power. I used to use any premium grade fuel but noticed that, after purchasing fuel at a certain garage, my car ran really flat. Therefore I have only used Shell V-Power for the past 4 months and the car has been running really well....up until last week.

I have thought out variuos scenarios why the car might run flat for periods but can't really pin anything down. At one stage I thought it might be down to a blocked fuel tank breather causing fuel pressure problems (the tanks sucks in a huge amount of air when I open the tank) but the performance isn't consistent with the possible causes.

The irritating thing is that I'm an Engineer and it's really starting to annoy me now. I guess I'll have to utilise 'Engineer's logic' and do what I always do when there is no logical solution.........blame the computer!

 

damn cars...

still trying to get a cheap used maf for mine... can't spend £240 on a new one right now...

 

Just an update. Bought some Maplin circuit cleaner and cleaned the MAF I'd bought - took all the cr*p off it.

Left it to dry for a day, and then installed it yesterday before I went to the Surrey Scoobies meet. The car does feel better it has to be said - I'll keep you posted.

I don't know whether I should maybe have reset the ECU (well, assume it does that when I disconnect the battery) before I changed the MAF - Simon - I'm guessing you could probably tell me if I should have done that or not (please!)?

Incidentally, whilst at the meet, Steve tested my bug for fault codes, but nada (a good thing I guess ).

 

when you tested the bug for fault codes why didn't you reset the ecu?
still haven't bought a maf...

 

Like I said, Steve did it for me just as I was leaving on the Sunday, so didn't really have time to ask him whether the bit of kit that he had could do it.

No biggie anyhow. Like I said, I don't know whether I actually need to reset the ECU if all I've done is change the MAF. I was hoping JGM might tell me if it's necessary, assuming he's got a subscription to this thread...

 

Bob Rawle did PM me back - he can get just the sensor for £80 new but they're out of stock at the moment.

 

hum, have to PM him too
thanks

 

reset would be nice but they do self learn pretty quick so should sort itself

 

Cheers Simon.

 

hi there, bought 2 used mafs, you think the best way to find out if they are ok is to do the unplug test?
or just drive for a while to see if the car runs ok?

 

I cleaned up the 2nd hand one I bought and just swapped them over. It seemed to drive better - at any rate I haven't noticed the performance probem I had before.

 

what you used to clean it? I fitted one of them and went for a drive, the car seems to be better, but after wasting 1 or 2 tanks of fuel I think I'll be sure.

 

Maplin circuit cleaner. Sprayed it on then let it run off. Wipe it off VERY GENTLY with a sensible cloth (i.e. one that doesn't leave loads of cr*p all over the sensor!) and then I left it to dry off for a couple of days.