updated tried the above

ok its deffinatly not the ignition switch as I cut the starter cable of the ignition switch so it would disengage when I take it off the live all the other cables work accesory and igntion circuit.

so ignition on alarm disarmed tocuhed the starter cable on the live van fired up opened accelerator keeping the starter cable on the live kept it on for 30 second and then took the cable the engine cut out still wouldnt stay running

tried this at both ends of the car kept the starte cable on the lie at the ignition and connected to the plug in the engine bay does the same thing

any ideas ?