So i have a 1996 jaguar xj6 and it runs incredibly well with the exception of when i first turn it on. Most times it runs fine, but sometimes when i start it(regardless if the engine is cold or hot) it will shut off on me when i come to a stop, or the idle will drop along with the voltage and the car will feel like shutting off but doesnt. If i turn and brake it will come even closer to shutting off. Anyone have any ideas? after i drive for 20 minutes the problem goes away but if i park and come back 15 minutes later there is a chance it will happen.

 

Any codes? Does the idle speed change when you turn on AC and lights? The answers will point to whether your idle control is working.

 

No no codes. Check engine light doesn't come on, and the idle speed doesn't necessarily drop when I turn on the lights or ac. But it does go down if the car is acting up and shutting off. When it's running fine it won't be affected by the lights or ac. also when the car shuts off sometimes a light on the top left of the dash that looks like a tranny with an X thru it pops up.

 

I have seen this fault on alot of AJ16 cars. (XJ6 and XJ-S)
You will probably have P1775 and P0727 in the ECM and/or TCM.
Could be IACV slow/inop or need the throttle cleaned and adjusted????

bob gauff

 

Check engine light finally came on and stayed on! Its giving off code p1775 as you mentioned. So what's the fix? I'm a newbie when it comes to jags.

 

EGR could be hanging open and stalling the engine????
IACV?????
Dirty throttle bore??

bob gauff

 

Hey bob thanks for the info. Where can I fInd the egr so I can clean it? Iacv?

 

The EGR should be the Chromed one if the Recall has been performed for your car. The original was a black one. The Idle Air Control Valve is on the throttle but the mounting screws are small and have thread locking compound. You will probably snap one or both if you attempt to loosen them without heating the area first.

You might need an 'engine setup' but you need PDU or WDS to perform this.

Here are some old TSBs for you when you get to 10 posts (then you can download).

bob gauff

 

Hey thabks for the info bob. I went ahead and switched out the egr and put a brand new one in. 152$ from Autozone. How long will it be till the computer learns the egr? It stalled and turned off already when I came to a hard stop. I've only driven two miles so you know.

 

It is probably not the EGR (if it is new it should not be sticking open).

bob gauff

 

Then I guess that leaves the iacv?

 

After doing a hard reset of the computer the car is running great, I guess the computer had to learn the new egr valve! Thanks to everyone for your input!!and here's a tip- the egr valve is the same for the jag xj6 as it is for the following cars-

*APPLICATION GUIDE

Buick Lesabre Sedan / Coupe (01-96)
Buick Park Avenue (01-95)
Buick Regal Sedan / Coupe (01-96)
Buick Riviera (99-95)
Chevrolet Impala (01-00)
Chevrolet Lumina (99-96)
Chevrolet Monte Carlo (05-96)
Jaguar Vanden Plas (97-95)
Jaguar XJ6 (97-95)
Jaguar XJR (97-95)
Jaguar XJS (96-95)
Oldsmobile 98 / 98 Regency (98-95)
Oldsmobile Cutlass / Cutlass Supreme (96)
Oldsmobile Delta 88 (99-95)
Oldsmobile Intrigue (99-98)
Oldsmobile LSS (99-96)
Pontiac Bonneville (01-95)
Pontiac Grand Prix (01-96)

Same goes for the iac valve! And these parts are available at your local auto parts store!

 

so the problem still persists even after changing the egr valve and cleaning the TB>so i changed the TB but now the car wont stop idling high at 2000 rpms! Any ideas?

 

Here are more throttle TSBs

bob gauff

 

hey bob thanks for the info, but unfortunately after adjusting the idler screw on the TB and getting the revs to drop the car now starts stalling again even after replacing the egr, putting a fresh and clean TB, and all. The only thing that hasnt changed is the tps. Also the iac valve came with the new TB and i left it on. any ideas? =\

 

Hey everyone, so i replaced the iac valve with a brand new genuine lucas one. The problem seemed to disappaer. But sure enough, after driving for a while and parking it, when i came back to drive it the problem re appaered! Car even shut off on me! It only happens during decceleration and i dont even need to apply brake for it to occur! Ive changed the egr valve, the TB and cleaned it thoroughly and now ive changed the IAC valve and still the problem persists! Help mE please!

 

Hi Guys... This thread sounds right up my alley- I'm so tired of not being able to fix the random rough idle or occasional stalling I'm about ready to shoot the kitty... when this car runs good it runs fantastic but there's never an in-between!

I've changed so many parts on this it's an official money pit- it would run great for 5-10 days then come back running same as usual - hit and miss... can anyone recommend a super genius in the Salt Lake City area to help me deal with this puppy?

I've lost all hope and confidence in it - brings me to tears and keeps me up at night trying to find something else that might fix it once and for all - or at least for a month!!!

sigh....

 

CHECK YOUR COILS, easy just remove the coil cover wait till dark and start your car. while the car is running look at the coils in the dark and if any of them lights up it is bad.

 

Thanks for that- they've all been replaced with new ones and.... some even replaced again just because they came up with a faulty code- swapping them to another the code followed the coil so out to the trash it went... no more codes - just a rough Idle now and again.

Thanks Jeremiah-

Johnny

 

So I don't have a coil issue, they all are working great and no dancing sparks. I have replaced one o2 sensor and now have all four working great. I will be going to the dealer to have a wds orientation done and hopefully that fixes it! I couldn't do it last time I went because I had a bad o2 sensor. Crossing my fingers and will update everyone when I get it done next week