Hi all, I had taken my wife to the hospital (broken ankle), left the car running, as I got her crutches from the back and helped her out. Got back in, the engine had stopped. It cranked but refused to restart. It was running rough on the way there. It had previously shown code 39 and I had removed and cleaned the EGR, although I now understand that code refers to the heat sensor which I have yet to tackle. AAA came and it was towed to my local garage. Time taken about 20 minutes. When down, the mechanic asked of the problem, sat in, turned the key and she fired up instantly and idled perfectly ! She had sounded 'dry' when I'd been cranking and there was too much ambient sound for me to detect whether the pump was working. Any ideas would be greatly appreciated. Oh she's still at the garage......Roger.

 

Hi Roger,

Intermittent problems are the worst.

I've had several domestic cars act up like this and it was the fuel pump.

A high percentage bet is that it's the Crankshaft Position Sensor - the sensor breaks down when it gets hot and cuts out the engine.

If you haven't already, you should read this XJ40 document provided on the Jag-Lovers website.

- Jag-Lovers' xj40 Ebook: Index Page -



G'Luck

 

Hi Trick, Thanks for the reply.. She starts up first time now but, I'm frightened to go for a spin, thinking it will happen again if the source of the problem is not found. On idle it now missfires on one cylinder but there appears to be no fault in plug leads or plugs (both are new). Any advise would be greatly appreciated.....Roger.

 

Hi Roger,

Test that fuel pump for adequate pressure. My mom's Tempo starting acting up like yours and after many sessions of determining "what is wasn't", I finally determined it was a faulty fuel pump. Live and Learn.

You wrote you replaced sparking plugs and wires. I've bought brand new bad wires before. Have you tried running the engine at night, pop the bonnet and looked for arcing and sparking around the wires and distributor cap?

You didn't say you replaced the distributor cap and rotor? For that matter, did you replace also the air cleaner element and fuel filter?

As for the misfire, I posted the following on the thread, XJ40 4.0 misfire when warm

Jump to d) Engine misfires (your problem)

Keep us informed of your progress, please.

o

 

Hi Trick, Started her up a few times, after leaving for a day or so. Starts straight up runs fine, no miss etc. Now I'm really stumped. I guess I'll just have to go on a run and hope.....Roger..

 

Well, if you're going to drive her in this condition, be prepared.

Carry a tool kit (e.g. a can of ether, spark tester, fuel pressure gauge, remote starter switch and what wrenches/screw drivers/pliers needed to attach/use these) so when she does "die" on you again, you'll be able to at least diagnose a "fuel" or "fire" problem.

I did.

Good Luck.

PS don't forget your cell phone

 

Thanks Trick, Took her out for a spin, went about 25 miles only, didn't miss a beat ! One thing, that I can't see is connected: The fuel gauge is playing up, it was reading anything from 3/4 full to empty, irrespective of how much was in the tank. Then it stopped on empty for the next 3 weeks, yesterday after I topped it off it went to almost 1/2, I've seen that I should ohm it, but what will that tell me with these symptoms (I'm useless with electrics). Thanks anyone with any pointers.....Roger.

 

Roger,

I don't think this is your problem, unless of course, you ran out of gas?

It sounds like you're gonna have to replace a fuel sending unit. I'll check later in Haynes on how to do it and post a sheet if I can.

 

Roger,

Here's a couple of pages describing the test and renewing of the fuel level sender unit.

 

Thanks Trick, Sorry I should have told you that I have the Haynes manual but, I think I need to get the major problem sorted out first. Well here we go again. Needed to run my wife to physical therapy. Started her, went about seventy feet it was missing just like it did the first time. Pulled back in and took another car. Got back four hours later, cranked her over, started right up with no miss ! Could it be EGR choked up connected , Wouldn't that be a constant ? Your help is greatly appreciated.....Roger.

 

Hi Trick

Your advice for Roger and from a spares guy here in NZ has helped me out immeasurably, just wanted to say a big thank you.

I'm going to give it a go tonight and let you know how I get on, hopefully provide some help for someone else

Cheers

Sam

 

Hi Sam,

You're quite welcome. Looking forward to reading your thread.

Remember, it's all about determining what it's not.

Good luck and keep us informed.

~~~~~~~~~~~~~~~~~~~~~

Roger,

Glad to read you bought a Haynes. It's a good deal.



I don't know about the EGR, but it's not on the list of usual suspects I provided above for you.

"Hit or miss" troubleshooting is time consuming, exasperating and in the case of a Jag‧u‧ar, expensive.

You've got to determine when the car "breaks down" whether it's a fuel or fire problem. That's why I wrote you earlier:

I'd like to add one more item to the "in case of breakdown tool kit" and that is a NOID tester.

Say "Hi" to my (your) little friends.

 

Hy Trick, As she'd started with no problem, I decided again, to run her into town. Went about 3/4 of a mile, it was missing at lower RPM but, seemed to clear if I gave her more throttle. However, as it mirrored the symtoms experienced before the first breakdown, I turned back and parked up. Now I have to think, why would giving it more throttle, temporarily at least, alleviate the problem.....Roger.

 

Boy is my face red ! A friend of mine asked me if I'd tested out the basics. I said I had but, then I thought, what would I be doing if she was older and before all this new fangled computer stuff. Injectors were working, how about spark ? Well it does run....SO....OK....I'll check the distributor cap.... AGHHHHHH. I've never seen a rotor in that bad a condition before ! Completely burned through, roasted ! The cap a mess. How the car ran at all is a wonder. The Jaguar Specialist had said these parts were replaced, when they did the head gasket, about 2,000 miles ago. Thats my excuse for not checking it out sooner ! Replaced cap and rotor....She's running like a dream !.....Thanks for your help Trick.......Roger.

 

Back to basics eh Roger? great to hear you found the issue though. My distributor cap was a bit corroded when I had a look.

Trick, I had it tested and sure enough, that was it. I have bought a new sensor and will fit it tomorrow, fingers crossed I'll go for a drive for the first time in two months, I'm looking forward to it with some reservation

 

OH NO ! Now she wont start, once again. Loosened the fuel line. There's no fuel getting to the rail. The current fuel pump has only done about 5,000 miles. Could it be anything else ? Help again please, would be appreciated......Roger.

 

Did you have the fuel filter replaced at the same time? Check to see if there is fuel getting to the filter or just swap it out if its the original after this much time.

 

Thanks Kirk, Took off the filter, it's badly clogged. Couldn't locate the pump relay, it's not where Haynes said it is, also the filter is not of the type they describe ! The pump is not running and, I'm beginning to fear the clogged filter has caused it to fail. Could it be something else ? Help much appreciated......Roger.