2003 172 misfiring under load on track

[Kart_uk]

Hi guys, some ideas if poss please.
I have a 2003 172 with 45k on the clock.
On track yesterday car suddenly started misfiring around 5k revs, (not popping or spluttering just cut the power) engine management light came on along with a green gear stick light. After a couple of seconds the lights when out power returned then few seconds later same again, this was happening in 3rd gear to start then 2nd and 4th as well.

We tried a process of elimination with changing coil pack and went back out and it was exactly the same.
Checked spark plugs for arking down the white element nothing.
Changed leads
Changed crank sensor
Also disconnected the lambda sensor
I went back out on track after each of the changes above to try and find out which one it could be. Unfortunately the misfire was still there.

We now think it's a fuel problem, Maybe not getting enough fuel when under load (injectors, fuel pump etc.?)
If you have any idea's guy's what you think it could be I would very much appreciate it.

Cheers.

 

[imprezaworks]

did you run the car low on fuel

 

[Kart_uk]

No there was 3/4 of a tank in it at the time. Forgot to mention we checked the throttle body at the same time and that was opening and closing as it should.

 

[Andy93]

Blocked/knackered injector?

I had a blocked one and it would clear up if you held it flat out for 20/30s but then would reappear after you backed off and went for the power again

 

[Kart_uk]

I did try keeping it flat for a while but lights kept coming on and power cutting, it was like a kangaroo effect in the car when it was happening if that makes sense.

 

[conorjones172ph1]

any luck with this mate have the same problem doesent want to start either