There has been several threads regarding engine stalling with the X300 (XJ6 4.0). This occurrs with mine now and then under simular conditions. It is always after about a twenty to thirty mile drive at a moderate speed with a slow down for a stop at a light or stop sign. It will stall when I add gas to start up again. Some times the stall can be controlled by quickly letting off the gas pedal for a second or two and letting it catch up. The severity is dependent on how hard the acceleration is. Gentle to moderate. Moderate will result in the car having to be stopped and restarted.

When the car gets in this mood I have noticed that it is getting very good gas mileage. Almost too good. Now this is modest driving 60 to 70 miles an hour. I'm thinking that during the drive duration the computer is adjusting the fuel trim too lean. And when you stop the mixture is too lean to handle the opening of the throttle and the engine stalls. Closing the throttle quickly for a second allows the fuel the catch up and it continues OK.

This problem is definitely fuel related. It is not electrical IMHO. It has happened quite a few times and always pretty close to the same conditions as described. If I put the car in neutral while stopped and goose it slightly before starting up again it has never stalled.

OK you experts. What do you think.

 

Funny you should mention this :-)

Just in the last couple days I've experienced rough running at idle and engine stall at idle, only after a 30+ mile drive, in most cases when comong to the end of a stop. No symptoms present while driving along

I have a come-n-go check engine light with code P1176 ---lean mixure.

Haven't had a chance to do much with it but checking live data during the rough running shows short term fuel trim varying from -5 to +5 on both banks....which, AFAIK, it about normal

Cheers
DD

 

Mine's fixed.

I got lucky....just (another) dying coil. I also got lucky in that, not long after writing the above post I went on errands and the problem became so pronounced that it wasn't hard finding the culprit....especially when the dashboard did the "Tokyo at night" thing....sure sign of a bad coil.

Not sure why a P1176 would set....have to do some mulling on that. Also not sure why a misfire code never sets when coils fail. The parameters set by Jaguar to set a misfire code must be very high

Cheers
DD

 

The P1176 *might* set because the H2OS sensor sees the mixture as lean due to the misfire since it sees the excess oxygen from the misfiring cylinder. It was one of the trick questions in the OBD quiz

 

I don't get a code. And I don't get misfiring. The engine runs smooth. Idles smooth. Gets great gas mileage. The problem is that after stopping from a modest drive at a red light and pressing the pedal to start moving again it is too lean and will stall when you press the pedal. On the old carb engines there was an accelerator pump that gave it a shot of gas when you pressed the pedal. That is what it needs. How does the TB handle this condition of adding an additional shot of fuel to keep it from stalling.

 

Believe it or not that was in the back of my mind when I mentioned mulling it over.

Oddly this is the first time P1176 has come with a coil failure....and I've had numerous coil failures. I was wondering what might be different this time.

Cheers
DD

(note to self: time to source a couple more spare coils)

 

We are off track. I need help to keep the engine form stalling due to a lean fuel mixture after highway driving for about half an hour.

NO CODE was set.

 

Ezdriver
I've had the same thing happen twice in last yr, but this is a little different, same as you drivers find, then all of sudden , sitting at stop, take off then wants to die, pull over to side, restart, but i have transmission fault lite comes on, doesnt really go into limp home mode, i can still driver it at 40 mph .like just this pass tuesday, was in town, i get home and take" EGR" out clean it good and the mounting area and the 2 holes, spray throttle body cleaner, back together and starts (takes a few sec, burn off cleaner) idles great transmission lite gone, this is twice in last yr, egr valve only has 18k miles.
What the heck does and egr have to do with tranny, do thise egr valve need replaceing ever 20k miles??????
Way back in 1997, we had a limp home mode, jag dealer in tuscon, az replaced egr valve, i've gone back thru all my bills and it seem my car had had about 3 egr valve put in, i did the recent one, myself.
Ok, everybody give input.
O just took it out on highway ran up to 80 mph runs like a top, no stalling, on the drive thru town, stop lites, idle great coming back to home.

Hthanks
Geno
1995 xj6 195,000 miles

 

What you describe is essentially the same as what I'm talking about. And mine also sometimes after restart does not start in the right gear, but a much higher gear than first. When this happens I just put it in park, shut off the engine. wait a few seconds and then restart the engine. It has always started up fine and been in first gear after using the proper shut down and start up proceedure. I didn't mention not being in the right gear as this often diverts the attention from the primary cause and that is initial fuel starvation. As soon as it stalls I know it is in first gear initially. The transmission is not the problem. Too lean at start up and no little burst of fuel to keep it from stalling