* Cold start: Always starts up great.

* Run the car for an hour, shut it off: It doesn't want to start for about 20 minutes.

And when I say "it doesn't want to start," I mean it sounds like a dead battery: Starter drags badly, then just locks up altogether. Car won't turn over.

The first few times this happened, my thought was the battery was bad. But it's a fairly new battery and it tested out OK.

Sometimes it doesn't take 20 minutes to clear the problem. Sometimes just a couple of minutes will do it. But basically, it's made the thought of taking a long trip a little daunting (because it doesn't want to restart after a refueling stop), and it also makes doing errands around town a little worrisome as well.

I'm thinking battery, the starter itself, or maybe the little Lucas box on top of the motor. What say you?

Jess

 

Sounds like a starter problem. Heat soak has taken its toll on it maybe. Don't get me wrong, these cars have a great starter, yet remember it is always right next to the cat, and stays hot all the time. Its a wonder they last as long as they do. When I had to take the exhaust manifolds off of my 89 to put new gaskets on, I saw how easy (lol) it looked to go ahead and take my starter off and have it checked. I have a good friend that owns a starter/alternator shop, and I watched him as he disassembled mine. In comparison to what new brushes etc looked like, his question to me was "are you saying this car started at all?".

 

I agree that the starter itself is a likely culprit. Often they'll give trouble when hot.

Check all connections first, though. Battery cables, ground straps, and the wires at the two "+" junction posts on the firewall. Removing a V12 starter isn't something you want to do without eliminating other possibilities.




That's the ignition amplifier. It wouldn't have any bearing on the starting circuit

Cheers
DD

 

Funny you should mention battery cables. I have to disconnect my battery every night because I have good ol' mouse belt seat belts and one of the limit switches is apparently bad. You get out of the car, and you can hear the driver's side belt motor cycling, thinking it hasn't pushed the belt forward enough with an open door. If I leave the battery connected all night, it will be discharged in the a.m.

Ergo, sometimes when I put the ground cable back on, I'm sure I don't get it tight enough. But the hot-start issue was present, to some degree, before I started having to disconnect the battery at night.

Jess

 

Whilst you are checking cables etc, this one needs checking for sure.

Coming FROM the starter relay, and ending AT the starter solenoid, is a heavyish White wire with a Red (probably Pink by now) stripe. On our RHD cars it travels behind the brake booster bracket, and at about the area where the bolt for the fender brace attaches to the scuttle, is a joiner, yep, a simple male/female spade joiner, and a nice rubber cover over the 2 bits. This joiner gets loose with age and heat, so unplug it, squeeze the female section a SMALL amount, and replug it. This will "firm up" the grip of the 2 bits, and has solved many a lazy starter for me over the years.

Next would be the contacts INSIDE the starter relay itself. They do get grubby with use and age. A simple clean can give new life to that relay, but usually a replacement relay is needed.

 

I appreciate the input; I just need to get an Australia-to-U.S. dictionary in here to translate terms like "scuttle," as I have no clue what that means.

Sounds like I've got a weekend of crawling around the garage, anyway. But I don't mind spending time with my old British friend.

Jess

 

Maaaaaate.

Same as I have with USA to "normal", damn.

The scuttle is the panel below the front windscreen, and has the opening in it for cabin air intake, and in the case of the XJ-S the wiper assembly is attached to that huge alloy finned thingy.

Open the bonnet (hood if you must), or, that BIG metal panel that covers the REAL engine, and you will see 2 Philips headed LARGE setscrews, 1 each side of centre, that attach the brace rods. This is the area that this joiner is in. It is NOT in your face as such, it is about 4" or so below that brace bolt, and you usually have to really look for it. I have found some of them just next to the transmission dipstick RED handle, and whe removing that dipstick to check the fluid, you CAN seperate that joint. So it is there, jsut hunt it down.

Start drinking, expand your vocabulary, drink some more, and Jaguar maintenence is real fun. Trust me.