3.9 v8. Random stalling

Hi. This is doing my head in. Hope someone can help.
Engine keeps stalling. Hot or cold. Usually on deceleration . Changed leads,plugs,rotor arm,dizzy cap,coil, and power pack thingy on dizzy. Cleaned air filter and plenum. Was set up and tested at garage. Ran perfect for 3 days.
My daughter got in car,slammed the door and engine stops. Now stopping whenever it feels like it. Inc.fast lane of motorway. Will start again after 2-3 minutes. Any good ideas?

My old 3.9 used to do that - it was a sensor on the FI system - can't remember which one, a Bosch technician sorted it out for £50 even though it was a Lucas FI system (copy of the Bosch Jettronic I think.)

It can be as simple as the fuel pump or a ecu fault get it read and check for air leaks too

Thanks. Can't find any air leaks. Try fuel pump next me thinks. Btw where is pump relay.? Not near passenger door I suppose. Lol

No codes show up as it always behaves when at garage.

My 3.5 efi did this once upon a time after high speeds or fast acceleration would stall on deceleration; pulling through all the vacuum/ventilation pipes to clear any blockages sorted it.

Just a thought, you said daughter slammed door, so how about loose wire somewhere. Maybe check ignition switch and anything loose at the ECU.
Cheers Nick

I had a stalling on deceleration issue when the vehicle speed sensor was not working. This is not the speed sensor for the speedo, but the device which let's the ECU know if the car is moving. Wouldn't cause cutout on motorway though I don't think...

just a quick update. found out i had a faulty inertia switch. all happy now. thanks for all your input

cool,glad its sorted