Hi Guyz, 1996 XJR 4.0 Supercharged has a problem.

after starting up works fine for around 3-4 kms drive then starts jumping the revs up and down to 1500 and low and to 0. Engine shut down on me while parking.

Any suggestions?

So far what's done is : removed injectors and cleaned them in mechanics shop with ultrasound, cleaned the injector rack, changed the fuel pumps - this last one we didn't find from Jag so we put from other car with same specs.

What's about to be done and checked: Will Fog the intake to see any air leaks

 

Fog-ed it - no leaks.

any ideas guys ?

 

Idle air control motor is very common on these cars, and that is one of the symptoms. Just so you know, the screws frequently break when removing. It is bolted to the intake, left side of the throttle body.