I have a 1998 Jaguar XK8 which has gone into Fail Safe Mode and refuses to start. I got home after a 30 mile journey and went to go out again but the car will not start. The engine turns and everything seems to be working fine but it no success and I've never had any real problems with it. I have checked the spark plugs, it has plenty of fuel and I have checked all the fuses, relays and the cam shaft position sensor and they seem to be fine. A friend of mine came and said he didn't think there was any spark. The Jag codes said there was a fault with the brake switch but surely that wouldn't cause it not to start? Any ideas?

I have had a small issue before where it ran a bit lumpy after it was re started whilst warm after a long journey. The car would try to stall but once it got moving it was fine!

 

Surely you have a CEL at this point. If not look to fuel as the problem. If CEL on then get the code(s) and post back.

Welcome to the forum. You are going to get a message from a moderator shortly advising to check in to the new member forum and introduce yourself.

 

Thanks. I did have someone come and read the codes but I don't have them to hand. We checked the fuel pump and it wasn't the problem. I think I'm 99% sure its electrical.

NO e-mail yet... I did join about 2 years ago though.

 

Well that was probably when you got the email!

Anyway, we always like new members to post an intro in the new members section.

 

Clint,
I had a similar problem a while back and it turned out to be the Fuel Pump.
I would check that first.
Dave B.

 

Thanks Dave, Pump was 2nd thing I checked and is working fine... It looks like their is no spark so i think its electrical related. really at a loss with this one!

 

All done! Thanks for the link.

 

Please don't take offense but how do you know the pump is okay. Did you put a gauge on the fuel rail? I found the easiest way to check spark/compression is with starter fluid sparay. Just don't overdo it - it may damage the plasic manifold.
Good luck and keep us posted.

 

Fuel pump is 100% fine, we have done various tests on it and its getting fuel to the engine. I've sprayed engine start fluid but it just won't pick it up. Ran a test and there just doesn't seem to be a spark getting to it so I'm thinking electrical. ECU perhaps (hope not).
As I've mentioned before a fault was picked up with the brake Switch but surely that wouldn't stop the car from starting?

 

You really need to have the codes. If there is a problem with the ECU, which I had, it can probably be repaired. Otherwise it's likely to be a connection that's corroded or loose.

 

I am not sure exactly how to check spark with these plug mounted coil packs but there is fuse 18 in the front right fuse box that provides power to the ignition coils.

Then there is the ignition relay.

https://www.jaguarforums.com/forum/a...1&d=1393677334

'getting fuel to the engine' is a little short of saying there is 40psi pressure on the rail.

If the issue is other than fuel there is a very good possibility that there is a OBD II code stored. Having the actual codes would be helpful.

 

Have you changed the secondary tensioners?

1. compression check- that will uncover a cylinder wash or secondary tensioner issue.

 

Try starting your car in neutral. I had a similar problem with my 97 XK8. It might be the neutral safety switch out of adjustment.

 

Thanks for the suggestions.
I've tried starting the car in neutral but that didn't work. All the fuses and relay are fine as is the compression thankfully. I think next step is to get the codes!

 

Hi Clint,
18 months ago I had the same problem on my XKR, same colour and year as yours. Car ran 30 miles parked for 30 minutes then no start.

I checked fuel pressure at the fuel rail, it was about 50psi and in spec, checked all the plugs, 8 good sparks. Followed by some head scratching.

I had a long chat with XJK hear in the UK and they suggested checking the relays under the bonnet on the left hand side under the large plastic cover near the bulkhead (RHD car). Under this cover at the front end of this area there is a plastic cover that lifts out, under it there are 3 relays that I never new were there, one is for the injectors and another for the ignition, I think the third was for the throttle control. Anyway I found that one of the relays had partially popped out of its fitting. I pushed it back in again and the car started immediately and no problems since. In your case it may be worth a look, in the end it took no more than a couple of minutes to make the fix and no cost.

I've attached a couple of images here if they will download (never done it here before).

http://i1353.photobucket.com/albums/...4/P1000699.jpg

http://i1353.photobucket.com/albums/...4/P1000701.jpg

http://i1353.photobucket.com/albums/...4/P1000702.jpg

Hope this helps.

Peter

 

Thanks Peter, I'll check that out... If not I think its off to the garage it goes!

 

I have a procedure that might help with your no start situation and I will provide a link. I notice that your car is a 98xk8 and that means Nikasil! When attempting to start the car does it sound like the engine is lacking compression?

Link JagRepair.com - Jaguar Repair Information Resource

 

Thanks, compression is fine so that rules out Nikasil hopefully!
Its at the local garage now and they claim that it has a fault with the key but we shall see!

 

Thought I'd update this thread with news that its finally been fixed!

I had taken it to a local garage who had said it was an electrical/ECU problem but after two weeks and no updates from them and no visable work I took the car back (at the cost of £200!) and took it to my local (ish) jaguar dealer who fixed it after 2 days. The engine lost compression and it had nothing to do with electrics so I was conned by the first garage!

Costly Lesson learnt i guess!

 

Loss of compression Nikasil! Glad you have it back on the road..