Leon Cupra Missing & surging on full power

[jockmonkey]

Hi Guys

wondering if anyone had some ideas on the following car..

2001 1.8T 20V Cupra, AUQ Engine code
done 116,000 miles but has been going well.

recently engine management light come on, so a mate who is a mechanic plugged in his computer, and we did the following;

New Temp sensor on the block
Replaced 3 pipes (1 from plenum and the 2 further down from it)
New Dump valve (as it was showing as faulty when we tested it through top hole)

Car runs and idles ok, unless you floor it, say pulling away from lights, pulls like a train up to 4000+ rpm easily in 1st few gears, then power dies, fades and surges slightly, then comes back again

No smoke, no heavy oil cinsumption, I don't think it can be the turbo as the car pulls so well initially, it is almost like a pressure problem somewhere, as it builds up boost then loss of pressure before coming back.

Any ideas anyone? I am wondering if the MAF could be the culprit, as the fueling level changes under hard acceleration it struggles and has the ECU over..

:1zhelp:

[the-moog]

I have a SEAT Leon FR 1.8 with what seems to be the same problem.

On full power the vehicle surges like I am pressing the throttle on and off, but more severe.

Any suggestions?

[jockmonkey]

Fixed mine, was DEFINATELY the MAF sensor (off the back of the Air Filter), some people also call this Fuel air mass meter or sensor too

Was not too expensive (think around £80 from local TPS (VW/Audi parts place)) was exchange price so old unit went back. Give me a shout if you are struggling to get one:beerchug:

15 minute job to replace.

To check it out unplug the electric connector at the back and try taking it for a run, if that helps don't leave it unplugged as it isn't too good for the engine long term. Replace it

But should allow you to narrow it down and see..