What happens when you unplug the MAF?

What happens when you unplug the EGR?

The EGR is not cheap and I don't think it will solve your problem. Unplugging a sensor could help determine the problem.

 

Before changing EGR valve. Please read........

Also for your reading and all of the fellow 1995/1996 XJS owners, is "XJS 1995 UPDATE" developed by Jaguar. Very informative regarding the changes made to this model year and the differences to previous years.
Will give background to what can be done to assist in regulating IDLE Speed in year 1996 XJS
You will notice that many controls ( ignition and engine management) thought to be adjustable are not, but controlled through ECM.
I have found that it was important for me to keep a copy in the trunk for backup.n

http://www.jagrepair.com/images/Auto...5%20update.pdf

 

Thank you Robert L. I viewed a little of this update. Loks to be very informative for the '95 and"96.
Cheers, RagJag

 

Yeah, that update is very helpful. I keep a copy on my phone at all times.

I tried unplugging the MAF sensor and EGR valve while the engine was running. It was idling at ~1400 RPM. When I unplugged the MAF sensor, the engine died immediately. When I unplugged the EGR valve, nothing happened. Am I right in thinking that means the MAF sensor is OK and I should replace the EGR valve?

 

No.

If I unplug my MAF the car adjusts to a open loop system and runs based on a set of pre-programmed parameters. The fuel economy sucks, but it runs smoothly.

The fact that your engine dies is strange. Someone else will chime in, but this should help someone diagnose your problem.

What would cause the engine to die when disconnecting the MAF?

 

Unplugging the MAF will result in eventual stall and engine light to be set in my AJ16. And my car idles according to factory specifications.

The EGR (part LHE1550AC) is in fact relatively cheap. Terry's Jaguar has it for 132.00 and two sellers in ebay have the original Jaguar part for around 80.00. If your EGR is stuck open with carbon, you could try cleaning it to see if that helps. But the problem is also that no matter what you replace, if the car had been allowed to run with high idle for a long time, the adaptations may have to be reset anyway.