V8 3.5 bad Flat Spot

3.5 V8 efi Flapper...

Bad Flat Spot/ Miss ? when hot...

Had a problem with the ignition Amp, so fitted a new one, now its developed a bad flat spot when accelerating from idle only when the engine gets warm/hot, from cold you wouldn't think there's a problem...

Tried a different...
Coil
Distributor Cap
Plugs
Leads
Distributor pick up point (inside the Distributor)

So I'm now pointing towards the fuel pump, maybe thats playing up when it gets hot, but that has nothing to do with the original problem...

I keep going round in circles...

Any ideas would be appreciated...

does it have a accelorator cable or a sensor as i had a bmw once and that done it and it turned out to be the sensor on the accelorator peddle (no cable)