car idles rough at stop lights and chugs sometimes at around 45mph but runs pretty good at high rpms and highway driving. took car to jag dealer and was told i had a bad coil and a bad injector. changed all 8 coils and spark plugs and the bad injector and it still runs like crap...also changed fuel filter valve cover gaskets, cleaned the throttle body. my mechanic is stumped and so am i.. the dash throws no engine lights or codes...does anyone have any ideas what might be causing this rough idle...very frustrated right now/ thanks for any help

 

If you have the 3.0 (which you should put into your signature) check this link out: JagRepair.com - Jaguar Repair Information Resource <--THANK YOU Gus

Don't forget to replace the upper and lower intake gaskets, FelPro has after market sets at great prices.

 

+1 (but see my .sig)

hmm, he says 8 coils so I GUESS it's a 4.0. (Shouldn't have to guess.)

 

whoops, my old eyes skipped right over the 8 part.

thanks JagV8

disregard post #2

 

I very nearly missed it, too

Also, I'm just guessing it's an 01 car from the alias, but plenty of people have traded up so it may not be.

 

yep its a 2001 4.0L....so the upper and lower intake gaskets could make it idle horrible too? could it be the ecu?

 

It could be any of a very long list and the PCM's towards the very unlikely end. ECU is a really bad acronym as it means more than one thing, btw. There are 10-20 in your car....