Engine dies when I put the car in gear
 

I just bought a used 2001 X70.....with a little problem...runs and starts fine but dies as soon as I put it ine gear.
Is this a problem anyone else has experiences or has experience with?
Thanks for you help in advance :)

Automatic transmission?
If so, it may be the idle air control valve not kicking in.
I'm not a mech, but my theory goes like this:
With the foot off the gas the butterfly valve inside the throttle body is kept a wee bit open to ensure the engine not to die at idle.
When you put it in gear (D or R), the engine is put under a bit of a load and requires more air and fuel.
The IACV is supposed to take care of this by opening as much as is needed to keep the idle steady under all sorts of load conditions.
If the IACV isn't working, the engine will stall as soon as you put it in gear.
What I'm not sure of is wether the throttle body has an idle switch or not in order to tell the IACV to start operating.
Either it relies on an idle switch or the output from the throttle position sensor.
If it has an idle switch then gunk in the throttle body may prevent the butterfly valve to close properly and activate the idle switch which in turn activates the IACV.
Clean the throttle body and the IACV and see if it helps.
The IACV can get gunked up preventing it from moving properly or the solenoid may be open or short circuit.

Does the engine stall if you engage the transmission with RPM's a tiny bit above idle?
If not so, then it could very well be throttle body / IACV.

Thanks emtor,
Yes, AT.
I will give it a try and let you know how it goes.
Thanks again.

I didn't express myself very clearly about explaining the workings of the throttle body / idle air control valve,so I'll try again:
There are two possible ways of designing this system,-either the IACV is dependent upon an idle switch in the throttle body buttefly valve to start operating, or it's activated by the output from the throttle position sensor when the butterfly valve is fully closed.
If you have an idle switch, check that it closes when throttle is closed.
Clean the throttle body/butterfly valve and the IACV. Also check the coil in the IACV solenoid for proper resistance value. Three things can go wrong with the IACV: Solenoid is either open or short circuit, the mechanical part is sticking or there's no voltage at the harness from the ECU.
After cleaning the IACV,make sure you have a new gasket or make one from double sided tape. I did the latter and it still works fine.