Hello Everyone,
1978 XJC Series 2 V12 D Jetronic FI Australian delivered new.
I've had my MAP Sensor tested by my local Mechanic (no Jag specialists nearby) and the vacuum test shows it holding pressure at -0.5 Bar for 10 seconds. The Resistance between 7 and 15 is 100ohms (should be between 85.5 and 94.5 ohms)
between 8 and 10 is 395ohms (should be between 346.5 and 353.5 ohms)
Are these results too far outside of the parameters?
This is the first thing I've checked in my mission to get the car running smoother. Currently drives well but runs rich. Strong fuel smell and revs increase to 1800rpm occasionally, after longer drive.
Is Dr D Jetronic the only option for repair?
Thanks

 

Mercedes used a similar unit. You might try to find one to see if it will adjust the fuel mixture within specs?

 

Yep,

BMW, Citroen, also used that system in teh same years as Jag,

Some of these MAP, have an adjusting screw (allen head) in the snout end. The thread are VERY course, so a small rotation makes a HUGE adjustment to the readings.

Some have a plastic cover on that snout, some do not.

Not holding Vac is the general failure, so with yours holding Vac, you are 95% on a winner.

 

I have a vague recollection that Volvo used it as well

Carl