I start the car and it cranks fine, but it's been dying suddenly, generally between 1 and 10 seconds of starting. Cranks well again. Repeat.

If I put my foot on the throttle and rev to around 1500 and watch the volt meter, when it hits 13 volts I can take my foot off and the car will stay running.

Alternator problem or battery? Battery is 5-1/2 years old but light duty. I could replace it but it's $150 I'd like to save for a rainy day.

Alternator is likewise a pain to get to and replace. Don't want to if I don't have to.

Thoughts?

 

if it cranks and cranks it can't be the battery.

sounds more like fuel starvation.

 

I'm with Jose. Sounds more like fuel starvation.

You could eliminate the battery/alternator possibility by attaching jumper cables from a second battery to your battery. If the problem persists you can be pretty sure it isn't a battery/alternator problem

The "Could be" list might get long. I'd begin by pulling the fuel filter and emptying the contents into a clear jar. What you see might be a clue.

Cheers
DD

 

Jose and Doug, thank you both.

I was hoping it was electrical because the problem only seems to be during that initial recharge period. Once the voltmeter's up to 13 volts things stabilize. I guess it's a coincidence.

Don't have a second battery at the moment (the other car is in the shop), but I'll try that when I can.

I'll check the fuel filter today.

-J

 

It could be be the fuel pump relay contacts in the air flow meter. These are bypassed when starting, and when the key is released to the 'Run' position, thses contacts supply volts to the fuel pump relay. It may be that the contacts need a clean and adjustment to ensure they make good contact. They are really, really, small, and the whole running of the engine relies on these; Not one of Jaguar's best efforts, I'm afraid to say.
You can check it is this, by taking the cover off in the trunk and connecting a light bulb on a long lead across the fuel pump contacts so you can see the bulb when starting the car. The bulb will light when the pump is supplied with volts by the fuel pump relay, and the car will start. if the bulb goes out when the release the key to 'Run' these contacts are not making good contact, or even no contact.

Of course the problem may lie elsewhere so do what Doug and Jose suggest too.

 

Thank you, if the problem comes back I'll do that.

 

Thanks everyone. I pulled the fuel filter, forgot about the jar part and just blew it out. Reinstalled and it runs okay.

In the back of my mind I wondered about it, but the front of my mind kept saying no, it's related to the voltage level and the fact that the battery is old--for some reason.

I know the "for some reason" makes no sense, but I've had goofball issues with cars where the solutions made no sense.

-J