Hello all,

After a 120km drive, at 110 km/hr, I arrived in to the suburbs and stopped at the first traffic light to find that the engine just stopped. Cranked it over, and it wouldn't restart.

Tried again after a minute (of pushing the car out of the traffic flow) to find that the car would start, but die, as soon as I engaged the transmission.

After a few more attempts, it would restart and run when the transmission was engaged, but die as soon as I tried to drive off.

After about 10 minutes of this behaviour, I eventually managed to start and drive off. It hasn't happened since, but has sapped my confidence about driving in the more populated areas!

Any thoughts as to what might have happened, and how I might prevent a recurrence?

Rhys Alexander,
Victoria, Australia.

 

The ignition coil, ignition module, and fuel pump are all apt to fail when hot and come back to life after cooling down a bit.

The coil and ignition module can be replaced for $100 (US) or so. As guesses go, that's not too painful. A fuel pump would likely be double that amount.

OTOH it could just as easily be a weak/dirty electical connection anyhwere in the fuel injection or ignition circuits. A good visual inspection of the coil wiring, relays and plugs on the firewall, the ground wires at the rear of the water rail, etc. might reveal something amiss.

I would get one of those inline spark testers (about $5-$10 in the US) and carry it in the car. If the problem repeats itself you can install the spark tester in a matter of moments.

Cheers
DD

 

Example of a spark tester. You can spend more or less than shown here

Amazon.com: Lisle 20610 Inline Spark Tester: Automotive

Cheers
DD

 

Thanks Doug,

Had only considered fuel issues... I should be more lateral in my thinking....

I hope it doesn't happen again, but I will bear in mind your suggestions.

Thanks,

Rhys

 

Heh heh. The old dilemma. Hope it *never* happens again OR hope it *does* happen again to allow at least a partial on-the-spot diagnosis.

Just knowing "has spark" or "does not have spark" with narrow things down quite a bit.

My money's on the ignition coil but that's just a long distance hunch.

Cheers
DD

 

Thanks for the explanation Doug, I have/had a similar issue on hot days with my XJ40.

Most everywhere I drive the speed limit is 60mph, but if after a longish run if I head into a stop sign, the car would shut down. Mighty annoying.

I discovered that if I brought the engine speed down over a longer slowing down distance, I could prevent the shut down and subsequent hot restart problem.

I decided that, it didn't like having constant high flow fuel, going straight to tick over fuel when hot.

I never have found the real cause for this, but just learned to drive around it.

I may well now look more closely at the coil side of things.

 

I wonder if others share this sentiment... these cars really keep us on our toes but damn they are fun to drive. For such "old" technology the way the Jag handles on open road or highway is unlike any other old or modern car I have driven. For that reason, I am willing to put up with the persistent tinkering.