Can someone confirm this is the proper sequence for replacing an Idle Control Valve?

XJ-S
21

Car starts right up when cold, but idles high. I can go through the ICV reset sequence to bring idle down.

22

That ICV sequence is really just a test to see if the ICV is ok. On the AJ16 engine, it doesn’t make any permanent changes.

If you’re idle is high cold, I’m going to hang my hat on a TPS reset.

23

A throttle potentiometer adaptation reset is done with WDS or IDS and takes a few minutes.

Some other diagnostic equipment might work as well but I only have both WDS and IDS.

The AJ6 engine TPS had slots in the mounting and could be moved to calibrate.

The AJ16 is simply bolted in place and then the ECM is told “THIS IS IDLE, live with it” when the throttle potentiometer adaptation test is performed

24

Gents,
Thanks for all of you feedback on my high idle issue. Unfortunately my wife tested positive for Covid yesterday and I am not going to able to take the Jag to a local import shop for testing. At this point, I am assuming a WDS will be required for further troubleshooting

I will report back once we both get the all-clear and i can get to the shop.

Thanks again!

1 Like
25

Not withstanding the advice on how to get a correct idle speed, remember that the controller needs to be in a fully open position before screwing it home else it will be damaged/destroyed.
It can’t be opened manually hence the need to electrically fool it to open before removal.

26

Back to my high idle saga. I am now convinced my idle control valve is receiving a faulty signal. Everything else checks fine and I have no vacuum leaks.

My local pick and pull currently has a 95 XJ6 with a 4.0. I pulled the original idle control valve off that engine and tried it on mine and got the exact same results that I got with two new replacement ICV’s. After going through the initiation sequence, the engine idles fine. However when I take it for a short drive, the idle locks in at 2000 RPM.

**Question: **Could I swap the ECM from the 95XJ6 with the ECM in my 96XJS without any issues? Both are 4.0’s

Thanks

27

I believe it works, but you’ll expect to have a ever present check engine light. One of those dash lights will not extinguish, and I forget which one. Maybe ABS?