Mechanics

JAGUAR XJ8 STARTER PROBLEM

1999 Jaguar XJ8 • V8 2WD Automatic •

I have to turn my switch off on 4 to 5 times to start my 1999 xj8. What is the problem help. Sometime it start right up.
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Isjeh061654
April 16, 2011.



Check the fuel pressure if its within specs if okay- Start by having your ignition switch checked out-

Rasmataz
Apr 16, 2011.
The fuel pressure is ok it is when I turn switch nothing happen with the starter no cranking and then the 3rd or 4th time it start right up.

Tiny
Isjeh061654
Apr 16, 2011.
Check the starter motor, relay, transmission position switch and ignition switch

Rasmataz
Apr 16, 2011.
Example of how to check starter motor, relay and ignition switch when I turn switch on it goes thru it system checks.

Tiny
Isjeh061654
Apr 16, 2011.
Locate the starter relay in the engine control center under the hood. Have a helper turn the key to start and check the relay input for voltage. If not present, jumper the neutral safety switch. If still no power, your starter switch is most likely bad.

If power is present at the relay output, locate the solenoid input on the starter itself and check for the presence of voltage. If there is voltage, remove the starter and take it to a parts store to check it.

Locate and trace the main power lead for the starter and ensure that it is in good shape, that the connections are tight and also in good condition, with no corrosion.

Rivermikerat
Jun 14, 2011.
Sorry, but I have to disagree with the starter diagnosis.

If you turn the key and the engine doesn't turn over, 9 times out of 10 it's the key not being recognized by the security computer. You can verify this by using your other key. If you decide you need a new key, they're $$$ because the security system computer needs to be re-programmed by the dealer to make the car know the key is acceptable.

Tiny
CraigInPA
Jul 21, 2011.
Craig, reread the original question. "Sometimes it starts right up". That doesn't sound like a key not being recognized. It's a starter or solenoid issue.

Rivermikerat
Jul 21, 2011.
Rivermerkat,

The security key issue is well known among X300 and X308 owners and mechanics. The FIRST thing the owner is told is to use their other key for a few days and see if the problem goes away. If it does, they come in for a new $75 key plus a programming charge to make the car recognize the new key.

I should add that the other thing that could prevent the engine turning over is the transmission interlock. When you turn the key, the brake is checked for being applied and the gear shift for being in park or neutral. Both of these are small microswitches that can be displaced over time. One at the limit of usefulness would exhibit this symptom. The third thing that would prevent it from starting is the immobilizer, but since this case presents itself as sometimes works/sometimes doesn't, that's obviously not it.

Jaguar gear starters are very reliable. I can't remember the last time I had to change one. Contrast that with interlock and key issues, and it's 99 to 1 in favor of being something before the solenoid itself.

Tiny
CraigInPA
Jul 21, 2011.
I would agree, but an unrecognized key is an unrecognized key. If the programming in the computer to recognize the key has "kicked the key to the curb" it will do it EVERY time, not SOME of the time. UNLESS someone has somehow flashed the PROM and added a cyclic counter algorithm to the key recognition algorithm, causing the system the accept the key every now and then, but to normally reject it.

The neutral safety or brake application switches are also good places to start, but, from over 30 years of experience, my first thought is starter or solenoid. The solenoid can be ruled out by connection a remote starter switch from positive to the battery's solenoid terminal and clicking the switch. If the engine turns over, the solenoid is most likely not the problem. Use a multimeter on resistance or continuity, with key off (battery disconnected, preferably) and check continuity across the neutral safety and brake applied switches. There's also an ignition key solenoid in the steering column that can be tested.

Rivermikerat
Jul 21, 2011.
I would also say that an outside possibility would be the ignition key switch itself is failing.

Rivermikerat
Jul 21, 2011.
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