Flat Spot at WOT

[Frenchy]

Huuuge flat spot on the Turbo S manifested itself today, back off and the car surges forward as it should.
Promax chips, 3 bar pressure reg, Bailey dump valve, resprung wastgate, i am thinking Air flow Meter ?
Anyone else had this ?

 

[Mike_Pollock]

Air leak?
Mike

 

[Frenchy]

Will be giving it a once over next weekend Mike and will be looking at all the hoses.

 

[Peter Empson]

I know nothing of Turbo's so feel completely entitled to make a fool of myself with the following. I'd have thought that over boost protection could be triggerred with the very cold air at the moment, but I'm guessing the after market chips bypass that anyway?

 

[944Turbo]

I had a failing coil that did that, somewhere deep in the manuals it tells you what the resistance should be between the terminals.

guessing - Could also be low fuel pressure?

was there a big black cloud behind? - usually accompanies a serious boost leak.

Good luck

 

[Frenchy]

Cheers chaps,
Got myself one of those sexy gel filled fuel rail pressure gauges which is reading 3 bar, so ok there, coil certainly worth looking at.
Pete you are correct in that aftermarket chips ignore boost pressure (Bang ! Whoops ? Shit £££££ ! )
Will get a good look at it shortly as it is parked up at my other garage (Good old Mam)

 

[barks944]

Perhaps the throttle sensor is involved. Does it pick up again when you are say at 90% throttle?

 

[Frenchy]

Yes Barks it does.

 

[barks944]

Doesn't sound like the AFM then, as the DME ignores it at WOT. I wonder what else is different at 90% throttle rather than 100% throttle. I would have thought any ignition fault or boost leak would be still present.