Restricted Performance

[Gordon from Edin]

I am sure this is a tired issue but can anyone advise?

My "experienced" mechanic mates think this is is an ignition coil as there is a slight misfire - causes a judder but car still idles at approx 800 revs.
Sometimes goes off and full power and kickdown are restored.
have fairly new plugs, so is it worth getting a new set of coils (£28) very cheap from eurojag.
I really do not want to take it to local Jag dealers as they are not nice people - been before!
From what i have read - most misfires seem to be coil related.
Keen to get issue fixed as car has attracted a lot of interest and i want to buy another Jag, cos despite the faults, i love them.
Also, does everyone else get a faint petrol whiff in car? My last two jags did this too so i assumed it was maybe just a big engine thing although i had two V6 Mercs that never did that......

I am amazed that a car with restricted perf will still do 80 on the motorway......

[jimattfield]

Gordon from Edin said:

I am sure this is a tired issue but can anyone advise?
My "experienced" mechanic mates think this is is an ignition coil as there is a slight misfire - causes a judder but car still idles at approx 800 revs.
Sometimes goes off and full power and kickdown are restored.
have fairly new plugs, so is it worth getting a new set of coils (£28) very cheap from eurojag.

Not yet - get a diagnostic readout on it first and if it is a coil it will tell you which coil(s) are playing up (e.g. P0352 code is bank #1 coil#2) then replace it/them. Note that if it is on bank#1 you will need to remove the air filter and duct to the throttle body to be able to remove the coil cover.

Jim

[Gordon from Edin]

Not yet - get a diagnostic readout on it first and if it is a coil it will tell you which coil(s) are playing up (e.g. P0352 code is bank #1 coil#2) then replace it/them. Note that if it is on bank#1 you will need to remove the air filter and duct to the throttle body to be able to remove the coil cover.

Jim
[/quote]

Thanks mate - got it booked for a diagnostic this week - my garage were using guesswork as the system they had would not talk to my car! Had to go to Lochrin autos as they were suggested by another PH chap.
Hopefully this will help to erase this and get the car really flying,,,,just in time to be sold.....

[P700DEE]

Assume you have not washed the engine or spilled some oil ? Classic signs of water/oil down the plug hole. You can just unplug each coil in turn until the engine does not get significantly worse at tick over to identify the iffy one.

[Gordon from Edin]

P700DEE said:

Assume you have not washed the engine or spilled some oil ? Classic signs of water/oil down the plug hole. You can just unplug each coil in turn until the engine does not get significantly worse at tick over to identify the iffy one.

Well,,,,, it came on 2 days after a major coolant leak which turned out to be a leaky hose - bit i got thru about 8 pints of coolant in the process.......will maybe have that looked at......thank you very much mate.

[pete5570]

I can see why you are off loading this car, you've had nothing but trouble with it! If you manage to sell it, don't bother trying to a get another "bargain". You get what you pay for, had you bought a good one in the first place, you wouldn't have had all these problems.
Pete.

[Gordon from Edin]

pete5570 said:

I can see why you are off loading this car, you've had nothing but trouble with it! If you manage to sell it, don't bother trying to a get another "bargain". You get what you pay for, had you bought a good one in the first place, you wouldn't have had all these problems.
Pete.

A misfire,a new idler and a new power steering pump? Not a huge list - woulda been shorter if my first choice of garage actually had the correct diagnostic equipment.

Still on course to make a profit - then i might just start AGAIN with another cheap one. Esp now i have found a great place to take it. I think i have caused the misfire issue by driving it when i knew coolant was peeing out.

[Gonewest]

Ive got a similar problem...light on dash starts flashing and it loses power.If I back off the light go`s out and everything is back to normal.Only does the once when first start driving.
Have found code P0303 and P1316....
Thanks

[jimattfield]

Gonewest said:

Have found code P0303 and P1316....
Thanks

Well if yours is a V8 of approx '99 MY the P0303 is the real code - sort it and the P1316 will go away. You appear to have a problem with cylinder A3 - could be lack of compression, injector, plug or coil. Time for a process of elimination but it would help to know what year and engine your XJR is first.

Jim

Edited by jimattfield on Monday 26th April 19:41

[Gonewest]

Yes...sorry.Its a 2000 xjr V8
Thanks for your help

[jimattfield]

The codes I quoted are from a '99 AJ27 (XJ8 etc.) so are I reckon are good for yours. A coil would normally show up as P0353 or similar - were it mine I would start by changing out the plug on that cylinder, giving the old one a good visual. If that didn't work I would swap the coil over from that cylinder to the adjacent one and see if the error moved. If it does, replace coil. Helps to have easy access to a diagnostic reader of course :-)

If that doesn't do it, time to start considering compression, cams and valve gear etc. although if it drives OK once it has 'cleared it's throat' that would suggest not mechanical bad news.

Jim

[Gonewest]

Thanks for that...I`ll look into it this weekend