Thanks all for the replies...

To clarify further, boost is held steady at 1 bar throughout.

It does do it in every gear, I don't think it's the drive by as I remember that from my old car, plus an ECU reset clears it.

Might try and find someone with a Delta Dash then...

Cheers

Simon

[Edited by simes - 7/6/2002 10:48:01 AM]

When accelarating hard my MY01 has developed a noticeable flat spot between 4200 and 5200 rpm. It's quite distinct as if a switch has been flickd to retard the ignition right back at 4200, and then flicked again at 5200 rpm to advanced it again.

It has started doing this recently, and I have ran through a couple of tanks of fuel to ensure it's not a fuel issue. It has always been run on SUL.

The car has done this a couple of times before and an ECU reset has fixed it, but this time I would like to get an idea of exactly what is causing the problem rather than just blindly reset the ECU.

It'll be going to the dealers soon, but in the meantime has anyone got any ideas as to what may be going on?

It has Scoobysport decat D/P and C/S together with Prodrive B/B and ITG panel filter, but has done the same when exhaust was standard apart from the B/B.

Cheers

Simon

I found switching from a scoobysport mid section/bbox to an HKS mid/bbox fixed this... Didn't notice the flat spot before I decat'd the centre.

Rgds, Alex

Thanks Alex, but I think it's different to what you were experiencing in that it's transient, i.e. an ECU reset fixes it.

And to clarify, when I say flat spot I mean the car feels like it's running at, say, 75% power, if that. There is a noticable kick at 5200rpm as full power comes back in.

Cheers

Simon

Simes,

What you have described is exactly what I saw.. the boost actually drops off to at circa 4200rpm to around 0.7-0.75 bar until circa 5000rpm then kicks in again to 0.95-1 bar.

Rgds, Alex

Boost should be stable right through, so it may be a sensor on its way out. A Deltadash log would show up exactly whats happening.

Strange this - I bought my SS mid + back box from Alex (and had initially the same set up (an ITG)), and haven't found the problem, so agree with Pete that it is not the same problem. However, I'm running a trick to fool the MAP and suspect that this may be your problem. Check the output from a DeltaDash (or Select monitor) first, but if the problem continues drop me a mail off line.

Duncan ;)

Simes, is this in every gear ? If not it could be something to do with the ECU reducing boost so the car passes the drive by noise test.

E.

Simes, this is no help but I have exactly the same set up as you (but with significantly less miles on the clock - infact you were at Scoobysport when I had all the exhaust done) and I don't experience this problem. As i said no help whatsoever but I'd be interested to hear how you get on with a diagnosis.

Piers LoFi

Drove car today and it's back to normal, pulling strongly all the way through. Only a quarter of a tank left, so it's not due to change of fuel, and obviously no ECU reset.

What's going on :confused: