Hello. I have a 1998 XJ8 that has started to cut out while driving. The sped can be any thing from 40-70 mph but it always happens going downhill. It has had a new fuel filter fitted by the local dealership. Any ideas?
Thanks

 

Welcome to the forum Loopykums,

I've moved your question from General Tech Help to X308 forum. Members here with the same model will be able to help.

Please follow this link New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum to the New Member Area - Intro a MUST forum and post some info about yourself and your vehicle for all members to see. In return you'll get a proper welcome and some useful advice about posting to the forum.

Graham

 

Throttle body issue???????????

bob gauff

 

Does it do it after a long time on cruise control?

Does it do it only when your foot is off the gas?

Any symptoms, lights, messages, etc will help.

 

Is the engine still idling, but will not respond to pedal input, or does it stall (tach to 0)?

 

Hello. I'm in Vancouver at the moment. 14 times between Kelowna and here. Foot off the gas, always downhill, no lights until it almost comes to a halt. Thanks.

 

Engine cuts out completely. Tach to zero.

 

If you can come to Langley, I'll clean your throttle body for you. It always fixes my car. I repeat it every 6 months or so because the problem will come back other wise.

But if yours has done it so badly, either you've got a really filthy throttle body, or a separate issue.

You can do it yourself by removing the intake runner between the air filter and the throttle body, then buy some intake cleaner and wipe out the throttle body and throttle plate. Spray some down the idle air valve while you're at it.

 

+1 on cleaning. Sounds like a real sticky mess.

 

Loopy probably came down the Coquihalla highway, made semi famous on the show "Highway Through Hell" on the Discovery channel.

Highway Thru Hell

There are very long downhill sections where you'll go for miles with little or no throttle, a bad place for a dirty throttle body.

 

I'm heading back on Monday. And yes I did come via the Coq. Joy.My email address is loopykums@hotmail.com

 

Unfortunately, I'm only around today. Do some searching on the forum. The only tricky part is removing the part load breather hose without breaking it.

Then buy some Kleen-Flo intake cleaner (or similar) and use a cloth to clean the body out really well. The idle valve is a passage in the throttle on the left rear of the body. Spray some cleaner down there and let it sit a minute or two.

Hold the throttle open and clean the butterfly and the bore. What happens is gunk builds up, then you close the throttle and it chokes the engine off.

You'll have to scrub with the cloth, spraying alone won't do it.

 

While you have the air intake hardware off to clean the Throttle body, clean the MAF sensor as well. Make sure everything is air tight when you reassemble. And please let us know if this approach worked for you.

 

Thank you eveybody for your help. Head home tomorrow so I'll get it done when I get back. Your help has been invaluable. I'll let you know how I get on.

 

Well it looks like the problem has been resolved. I took to the dealership and they cleaned out the throttle housing and tested it for a week. Got the car back and so far so good.
Thanks everyone for your help. Much appreciated 😉