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Matt
Matt, Mechanical Engineer
Category: Jaguar
Satisfied Customers: 22252
Experience:  BEng hons Mech engineering, in auto industry 22 years
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The engine just cuts out, we have had a diagnostic check done

Customer Question

The engine just cuts out, we have had a diagnostic check done and it shows nothing in the management system. It must be something outside that system! Put it into netural switch off and it restart without any problems, into gear and away you go .But it is disconcerting if you are overtaking!!!!! and we want to go away with it to France but are worried to do so with this problem Only had the car since January and apart from this problem it is fantastic to drive [wife complains that I don't let her have a drive!!! Roger [email protected]

Submitted: 4 years ago.
Category: Jaguar
Expert:  Matt replied 4 years ago.

Hello


This could be a wiring issue as things tend to expand when hot and its possible a poor or partial electrical connection is being pushed apart on one of the major sensors so check the connection plug and wiring to the following;

Airflow meter

Crank position sensor

Cam position sensor

O2 sensor

Throttle position sensor

Also worth checking the connections to the fuel pump for the same reason - unplug each in turn and give them a good squirt of switch / contact cleaner - Not WD40

and also unplug and inspect the main power relays and fuses for signs of overheating or corroded terminals - so the ones for the ECU and the fuel pump

And also unplug the wiring loom connections in the engine bay one at time and inspect for corroded or recessed pins.


Also its worth checking that the electric pump that feeds the injectors is working correctly, it should run for a few seconds then switch off when you first turn the ignition on. If the connections to this are corroded or damaged then the pump could stop at any time. Check that its relay switches in and out and the relay contacts are clean and bright – replace the relay if in any doubt and do the same for the fuse, ideally measure the voltage at the pump and check its getting 12V