Hi all. Got a strange one here. Sometimes randomly when i go to my car after its been sitting all night i go to start it and ot stalls so i have to rev it and keep flicking the throttle until it warms up for a few minutes then i can release the throttle and it ticks over fine and there is no problem with engine after that. Its happened a few times its been fine for 2 weeks then it happened again this morning. Any ideas would be very helpful.

 

Which car? What year?

 

Oh yeah. Its a 2001 XK8 V8 4.0L

 

I had a similar problem with mine early on. I checked the feed from the throttle body to the air box as they develop cracks and start giving codes and throttle stumbles. It was good, so I changed the air filter and cleaned the MAF sensor. I also cleaned the throttle body itself.

Been fine ever since. Cheap and simple to do, and it might solve your problem.

The routine is now an annual event for me, along with changing the oil, etc.

 

Ill give that a go thanks, Its worth a try.

it happened again this morning kept stumbling on me, i kept pressing the throttle but that wouldnt keep it running eventually after keep cranking it i got it a constant 4,000 revs and held it there for a few minutes then slowly lowered the revs and after that it was fine again.

Do you clean the maf sensor and throttle body with carb cleaner?

 

Excellent advice for preventative maintenance.
Graham

 

No, there is a cleaner specific for the MAF. Several brands out there, but make sure it says MAF Cleaner on the label. I use CRC brand, but any of the name-brand types should work.

There is a how-to on some thread, maybe in the DIY sticky. It's an easy DIY.

OK, found one link: https://www.jaguarforums.com/forum/x...-sensor-78178/

 

Its doing it on every morning start up now. It was popping and stuttering and smoke was coming out the exhaust when it was popping trying to keep running. It was hard to keep it running till it warmed up. It felt like ignition? Could it be the coils?????

 

Time to get a code reader on it to see exactly what is happening. Misfiring can seriously damage the cats.

Graham

 

Well i cleaned the throttle body and maf sensor airbox and filter today. The throttle body was caked in gunk so hopefully she will start first time monday morning. Fingers crossed

 

Well it started this morning ok. was hunting a little when it was trying to tick over at about 600 revs.

What is the start up procedure on these engines.
start up about 1,200 revs then 15 secs slows to about 1,000 revs then goes down to 600 revs after about 45 secs.

is that normal?

 

The progression is normal. Mine doesn't normally take that long, but you are about right.

 

Had a look under the bonnet and noticed this




Why would there be oil on and around those bolts? Its only on one side the others have no oil and are bone dry.

 

Slight weeping of oil through the valve cover gasket at the bolt holes...nothing to worry over. Engines do tend to get dirty over time.



.

 

MY CAR IS FALLING APART!

After all the issues with the engine stalling on startup and shaking abit when cold i thought that was all i had to fix but last night i was driving normally and i got the message engine failsafe mode/ gearbox fault/ asc and others and i couldnt rev the engine or go above 30 mph so i stopped turned ignition off and on and it was ok for 5 miles then happened again.

happened 3 times on my way home from work. im scared to start her up again to see whats gonna happen next.

 

As Graham mentioned above (and WhiteXKR) who are two very knowledgeable guys in these forums, if they make a suggestion it's like when I was in school and a teacher was pointing me to the answer... so at this point it's fairly important to pickup a OBD2 scanner.. you certainly have some codes being thrown, posting them will help these guys point you in the right direction.
Good luck and don't panic, just follow the advice and tutorials in these forums and things will be ok..

 

Sounds like a failing or flat battery. How old is it? Has it been kept charged on a good battery maintainer?

 

Ok i got some codes. I drove back from work with it logging the data live didnt really no what to be looking for on all the dials but the codes were
Stored codes
P1122
P1646

Pending codes
P1000
P1646

Any ideas

 

First your can Bookmark this: https://www.jaguarforums.com/forum/x...d-codes-45032/

Now:
P1646 Linear O2 Sensor Control Chip (Bank 1)
P1122 Pedal Position Sensor A Circuit Low Input

While other will give you better advice as they have more skills/knowledge than I my short of this would be you have a sense problem on one bank. Could be a air leak somewhere (search forums) or maybe the MAF could used cleaned, I don't know if the 1646 is saying the sensor is bad or it's reporting from the sensor.

Do a search in these forums on this and see how others went about it, Good Luck

 

I have just had the O2 sensor changed for a new one????

and P1122 looks like i need a new throttle body, great news