Tuning a Suzuki Swift GTI

[Trafford]

I`ve been tuning a Twincam Suzuki Gti engine which I`m going to eventually put into my car.

So far all I`ve had done to the engine is a new filter and I`ve had the cams re-profiled by Piper, nothing aggressive, just fast road. I`ve also installed some new leads and plugs.

Everything was hunky dory and I was supposed to be doing the engine swap this weekend, but I`ve suddenly started getting a very annoying problem with the engine revs. The engine idles fine, but it won`t turn anymore than 2,500rpm before the engine cuts out, it doesn`t die, it just falls back to idle.

I can floor the accelerator pedal and it does the same, up and down, up and down. Its puzzling me. All I can think of are the following possible problems:

1.Throttle Position sensor needs adjusting
2.Lack of fuel e.g. either fuel-pump or fuel management table on my ecu.

Any ideas at all would be most welcome....

[StuiE]

Could the ECU have gone into limp home hode? Not sure how that would happen on a GTi engine, but AFM & o2 sensor issues can cause it on other engines.

[SpawnyWhippet]

Save your money and spend it on a car that was designed to be fast from the outset. You will have much more reliable performance, much less depreciation and people won't point at you and laugh in the street. There's no point in polishing a turd.
I will never understand why people spend 40 grand modifying a Vauxhall Nova when they could have bought a Ferrari F355 for the same price.
(sorry if this isn't the kind of technical answer you were looking for! )

[SpawnyWhippet]

Sounds electrical to me.
What make is the ECU, and have you contacted the manufacturer? Have you got the timing sensors, O2 and lamda sensors all properly connected and functioning? Can you run diagnostics on your ECU? What make are your throttle bodies? Have you got a decent voltage running to the electrics, no dodgy regulators etc?