Hello. My XK8 is having a stalling issue. At around 65-75 mph, under no load, decelarating or coasting it has been stalling. This just started to happen. I will be changing the Fuel filter. It has happened 3x in last week. Had not happened in last 5 months. New: computer, throttle body, plugs, coils.

I think my cat converters are clogged or done. How would I know? It failed CA emmissons as a GP, Very high.

I am also getting a tapping/ticking noise only heard inside the cabin (when warm)coming from motor, Replaced the entire exhaust (minus cats) from an XKR. Need to run smoke test and check for leaks still.
Can't be heard outside car listening from motor, just inside, very noticable under hard accelaration. Possibly valve noise? Motor replaced at 85k miles. Car now has 151k miles, full service history.

I was laid off and will need to do repairs myself. Most experience with Porsches; building, racing, modifying.

Have great access to used parts. Serveral XK8 in wrecking yard near house, good friend owns...

 

Well, if you're experienced with Porsche's, you can certainly handle a relatively conventional Jaguar.

There's absolutely no car as hard to deal with as a Porsche 911 derivative car. The engines are a nightmare to rebuild.

Good luck. Sorry I don't have suggestions to your problem. Codes?

 

paul thats your throttle body/

 

An intermittent fault - the worst pain. This car has had a lot of replacement parts:

1. engine has done 65k since it was swapped and the one that went in is likely to have had some miles under its belt before that.

2. changed ECM, TB and coils therefore car already has a history of engine management issues.

3. intend changing fuel filter so fuel starvation must be suspected

Lots of harness plugs will have been disconnected / reconnected during this swapfest. Has anything not been positively snapped back together - any loose or damaged connectors / harness breaks.

The basic question with the stalling has to be is it engine management again or fuel?

That comes back to why the ECM /TB were changed and how the parts were sourced. Presumably the MIL was illuminated - codes read - faults identified - parts swapped - codes cleared. Were new / tested parts used or were they straight out of wrecking yard?

As a minimum, have the codes read to determine any stored or pending DTC's. Ideally stick a scantool on it to see what's actually happening with ignition and fuel. This will also give you a health check on the cats.

Check fuel pressure for possible fuel starvation. It could simply be blocked filter but fuel pump failures appear to be almost an epidemic on XK8's in the US from the number reported here.

 

it was replaced with a factory part at jaguar dealer in 2009. dead already???

 

the reader gave me no codes. start with fuel filter first today. do you know if i can use a fuel pump from a 2002 xkr?

all the parts installed were done by previous owner, all factory parts done at dealer. they spent big $$ on keeping this car in good shape. he is a pca member and races a gt2 and a gt3.

future parts come out of wrecking yard as they are free if i pull them saving $ while i am looking for new work.

cats are a pain because they have to be purchased new..very expensive in California.

i went through and cleaned every connection i could get to in engine using electrical parts cleaner and putting back together with dielectric grease.

i feel it is a fuel issue and will pursue that first today.
thanks for your help!!!

 

There's several fuel pumps listed against VIN range. The XK8 and XKR have different part numbers. If the one you've sourced looks identical to the one on the car, the difference is likely to be the R version has a higher flow rate.

 

Throttle body plug (pins in connector) is my initial guess, but I've been wrong about highway stalling symptoms before.

The ticking you here, is it steady (no change with RPM)? If so, does the sound like its coming from your left foot area? If your still nodding, the ticking may be coming from the purge control valve. I started a thread on that.

https://www.jaguarforums.com/forum/x...er-side-49469/

 

xk8 paul, what type of fuel are you putting in the cat. if you are not putting the best fuel if you will, carbon will build up in the throttle body. and do you know if the previous owner actually got a new throttle body for that vehicle. Our throttle bodies on our xk8 are basically computers. no fuel goes thru them they are air measuring computers. coolant jackets are in them to keep them cool. look at that throttle body , it has two throttle position sensors ( one going low to high and one going high to low.) these are very vital parts for this vehicle. TAKE THAT THROTTLE BODY OFF and inspect it very well. look at the butter fly, and if you see any oil in the electrical parts, or if that thing just dont look right, its junk. you can buy a used one for 300 bucks or you can get it rebuilt from some guys in tennessee ( or how ever its spelled. good luck to you my xk8 distant brother!!!!

 

there is one more statement I want to make. People think just because a technician at a dealership replace a part or two that their word is stone: The real fact is dealer technicians are men just like you and I. Ive found that a lot of these dealers and mechanics dont really know their butts from a whole in the ground. These are our xk8;s and the only way we can keep these things running is to help each other and study our cars, because all a mechanic or a dealer technician want to do is get a whole lot of cash out of us for a whole lot of nothing and guess work. thank you and Ive spoken my mind. XK8'S FOR LIFE!!!

 

I had the same problem with the car shutting off at highway speed. There was a ring of carbon at the throat of the TB which was allowing the butterfly to get stuck shut. There is supposed to be about a .003 gap when the throttle is off. Mine shut off once and it didn't happen again for a year...then 3 times in one week. I opened the throttle with a stick between the seat and pedal. Wrapped a rag around a toothbrush soaked in TB cleaner and removed that carbon ring. I've driven it 3000 miles since and it hasn't happened again.

 

yep. this looks very likely... thanks!!!

 

throttle is super-clean. in California we only have 91, always run in car. but as i live on the beach there is always lots of moisture...

since i have cleaned all connectors no issues yet, running very nice.
thanks for the input!

 

agreed. this forum is of great help. fixed a ton of little things with the car in last week thanks to the forum! as i have the time i am going to do everything to the car i car to keep it running as new. my uncle always says you just need to be 2% smarter than the car you are working on...

 

thanks. they are the same. idk if flow rate is higher, but that is likely.

 

thanks for the video, same sound, and location of my car will be replacing that part.

 

Nice, glad it helped. Earlier MY uses a little diff procedure, I think whiteXKR described his replacement experience in that thread too.

 

update> cleaned throrrle body with toothbruch changed fuel filter and cleaned connectors. runs even better now. throttle is super touchy running fast. thanks for the help.