I have a 1999 Jaguar XK8 and just had the engine rebuilt, however doesn't start easy and just turns over, then she starts and runs great. However she does stall and then hard to start again. My mechanic replaced the Throttle Position sensor body and she still is hard to start and stalls. Now what?

 

lots of things, check pressure at the fuel rail before cranking the engine (IIRC 40 psi is about normal), then watch (or monitor the pressure via an OBDII scanner) during cranking and after starting (jumps to over 50 psi in mine). Are there any stored engine codes you could find?

when she does start, is it smooth, or always rough and staggers?

What kind of rebuild, can you describe the new parts list?

 

My mechanic says he rebuilt the whole engine. New Crankshaft, cam shaft ect.... There are no codes appearing except check engine light. The car cranks over 2 or three times then starts right up. It does stall then hard to start again 2 or three times then starts up and runs pretty damn good. We replaced the Throttle Position Sensor entire body and still same problem. My mechanic is dumbfounded?

 

I think the throttle body needs programming to the car and that needs the Jaguar software. Maybe it's that. If the check engine light is on I'm surprised no codes are storing. What are you reading them with?

Regards
John

 

Provided the battery is disconnected before the Throttle Body is changed, there's no need for programming a replacement. The ECU sets default values and 'learns' the new TB as you drive.

Check Engine Light (MIL) is not a code, it's a warning light. If it's illuminated, there must be stored codes indicating why it's set.................?

Graham

 

Thanks for all your post. Since I have a mechanic doing the work not sure but I will relay the information.