As some of you will know I have a fuelling problem with my sierra cosworth 4x4. Step by step I try to find out what causes this to get so lean like it is now. I discovered this at a rolling road session 2 months ago.

Well I tried numerous things like :

fuel pump wiring (after new wiring the voltage went up from 11,5V to 12,9 V),
new fuel filter,
checked the fuel lines,
fuel pressure check,
new map sensor,
new rotor and distributor cap,
checked the timing,
checked the TPS,
measured the CTS and inlet air sensor

All seem ok..

This weekend i fired her up again and what I noticed was that idling when cold was ok. But as soon as you hit the throttle it seems it only gets air sucked in and no fuel (don't know how this is called in english).

My first thought about this is the CTS (although I had measured the resistant when the engine was cold and the value matched the service manual requirement).

So has anyone had this problem and maybe can give me a hint??

Because I don't know where to look for anymore...