Hey all,

I just recently bought a XJ6 (about a week ago) and the car was running like a champ. There were no issues to my knowledge when I bought the vehicle, ran the scanner through it and had my trusted mechanic check it out before purchasing, and was driving it every day for short periods for about 10 days. Go to start it yesterday and it turned over and caught but the RPMs were wavering at 1000 RPMs and the whole car was shaking. I let it sit for a moment because this really threw me off and it somewhat calmed down so I cautiously put it in reverse. Didn't make it 2 feet before the car shook violently and sputtered off. Tried to start it again and the engine sounds like it really wants to start but the engine shakes and shakes and there's no ignition whatsoever.
I've only managed to get it started again for 3 seconds before it does the same thing.

I now have my battery light on, oil light, and check engine light but when I plug in my scanner I get no codes whatsoever and I have no idea where to even start as ignition problems could be a vast amount of possibilities from what I know.

I'm not sure if this is relevant but 3 days prior the interior lights would flicker, more so turn into a strobe light, when only the driver side door is open.

If anyone has any idea of where I could start to trouble shoot this issue please let me know. I just bought the car and have been without a vehicle for 3 years and I'd rather not resort back to walking again.

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1997 XJ6 (added by GGG)

 

A repost of your question in the X300 forum will bring you more answers. These are 1968-1992 models here. Link below.

https://www.jaguarforums.com/forum/xj-xj6-xjr6-x300-26/

 

Welcome to the forum cst2561,

I've moved your question from XJ6 & XJ12 Series I, II & III to X300 forum. This is the place to post technical questions about your model.

Graham

 

Thank you! I had no idea I was in the wrong forum.

 

With no engine code all we can do is guessing. I would start by physically check ignition coils (basic resistance and visual damage) , spark plugs (all flooded with fuel , or one or more with no fuel), loose or corroded wires connection, fuel pressure, compression test each cylinder, fuel injectors. Try to use a different scanner. Auto part store has loaner scanner, fuel pressure test, compress test kit, and volt meter that you can take home and test.

 

Go back to basics and put a new battery in; at least you will be starting on a solid basis then.
Dodgy batteries can appear to be superficially ok but can cause all sorts of problems if they are not top line.
The more modern the car, the bigger the problems that occur due to dodgy batteries.
Once you have a new battery in, see if there are any changes.
Don't forget to note the radio code before you disconnect!

 

Did you happen to fuel up shortly before this problem occurred? It could be that the fuel is contaminated with water (the water will make it's way to the bottom of the tank). If this is the case, there are additives that are supposed to mitigate it.

Trouble like this could be seen if the Crankshaft Position Sensor (CKPS) has failed. It is a known cause of poor running and needs to be replaced if it hasn't already. They don't last forever and they are difficult to test with a high degree of certainty. It is located at the front right of the engine and reads the toothed wheel on the pulley.

When you pull out the ignition coils, check to see if they are from Diamond (originals). If they have all been replaced with aftermarket coils, the aftermarket coils can fail quickly in this engine. Of course the old originals can fail too, but usually the failure is not as dramatic as you describe. Like the CKPS, coils are difficult to test and most owners will replace them one or two at a time, in a pattern, to see if the engine runs better, the same, or worse.

The flicker of the interior lights is a commonly seen fault, caused by the door latch microswitch (in your case, the driver's door). The switch needs cleaning, but that is a latch-out door disassembly job. A quick fix is to simply remove the bulb from the "puddle lamp" at the lower corner of the door, behind the red cover.

North American X300s don't have radio codes, nor do they have key transponders like UK models do. Two less things to worry about!