Could my idle problem relate to a problem with the intake air temp sensor??

The car has a ff4, rich mixture problem
Poor driving performance
intermitent ping.
higher than normal idle.

 

I guess the short answer is yes, the IATS could affect idle. At least on the 4.0L cars the IATS is a secondary input for correcting ignition timing but it is not directly involved in fueling. It's possible that if your IATS were stuck at a high resistance or was shorted the ECM could think the ambient temperature is extremely cold and as a result might apply an inappropriate timing strategy.

I don't know how different the engine management system is for the 3.6L cars, but you might find some clues in the 4.0L EMS Diagnostic Manual, which you can download here:

AJ6 4.0L Engine Management System Diagnostic Manual / OBDI

Also, another friendly reminder to please add the year, model and engine information of your car to your signature line. I had to go back to post #14 to be reminded. Some folks won't bother.

Cheers,

Don

 

Today I did make some positive progress.

I disconnected the IAT sensor and in place connected a resistor.

Started the car and she sputtered and the idle droped off and came back to 800rpm.

So now the idle is approximately whete it should be. A bit of a shake but an improvement for sure

IAT is on order.


The engine.managment manual, is there such a thing for the 3.6l??

 

If there is, I don't recall finding it as a free pdf download anywhere online, but it may be on one of the DVDs available from the Jaguar Daimler Heritage Trust (jaguarheritage.com). I'm away from home so I can't check the DVDs.

But the principles of operation of the Engine Management System should be virtually identical between the 3.6L and 4.0L cars so the manual I linked to earlier should be relevant to your engine.

Cheers,

Don

 

Big improvment today!

turns out a huge part of the problem was my brand new Taylor Spryo 8mm ignition wires.

could not hear them arching and had no reson to think they had a proble but, in the dark that was a whole diffrent story. There was spark crawling all over the from the wiress Not ionization. Thought maybe a bad ground so i used my jumper cable from the block to the battery negitive terminal with no change

changed the wires out the univeraal MSD.

My fuel fail 4 is gone.
Idle no longer hunts around on cold start.
Tonight i am going to try and get the idle set correctly.


Cheers!

 

[QUOTE=XJSolver;


-set TPS to 0.6 volts at closed throttle
-set throttle butterfly to 0.05mm or 0.002"



[/QUOTE]


When Setting The butterfly Clearance to .002,
What is the .002 in reference to?

Is this the clearance between the butterfly and the wall of the Throttle body?

 

Yes. Put the feeler gauge between the bottom of the butterfly and the throttle body.

Larry