Hi can anyone help me, i have a x300 4.0 1996, it takes a lot of cranking over to start on a cold/hot engine, but when it fires into life it runs perfect with no heistation or missing, just a bad starter. i have replaced plugs, front timing pully sensor, throttle postion sensor, idle sensor air/fuel filter. No change, is there anyone who can advise problem.

Welcome to the forum Paul,

I've moved your question from UK Region section to X300 section. Members here with the same model will be able to advise on starting problems.

When you get a minute, please follow this link New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum to the New Member Area - Intro a MUST section and post some info about yourself and your vehicle for all members to see. In return you'll get a proper welcome and some advice on posting to the forum.

Graham

Paul:
Believe it or don't... but the X-300 engine will try both crank orientations relative to the cams if the cam position sensor is faulty. It trys one, then the other rotation for spark. You might very well have a failed or improperly oriented CPS. Thats the one that looks like a short distributer and mounts on the front right of the engine where the distributer used to go.

Ross, many thanks for your reply, i will try changing that component, and see what happens, if no change i think its best to get the car on a diagnostic machine, once again many thanks
Paul

Paul:
Of course, the other well known issue for these engines is failing ckps - the crank position sensor. Although I have not seen it reported, a possible failure mode would be dodgy starting due to bad pickup at low crank speeds, but apparently they usually fail as the engine heats up. See if the tach registers at about 250 rpm while cranking- if so, it probably IS NOT the ckps.
Good luck.

hi ross, i have tried reversing the sensor in case it had been put on 180 degres incorrect, no difference, in fact it made no difference at all even when the sensor was not connected, still started after a lot of crancking, and runs beautifully, so the problem lies with that component one way or another, perhaps it couild be the ecu unit itself, back to e bay searching for bits i am afraid.
thanks
paul

Agreed, Ross...

Paul,

In my experience, the slightest rotational adjustment of the cam position sensor has a major effect on starting ability. But once running, all seems normal. Was the sensor disturbed (moved) before the problem began? Have you tried rotating it very slightly one way or the other, then trying again? Not exactly a scientific method, but probably worth a shot.

Paul:
In addition to Richard's advice, I would be suprised that the car has not thrown a code. Is the "check engine light" on?

The device is a Hall effect sensor, so you should probably NOT use a test light, but rather a meter or scope. The black with brown stripe wire is the pulsed signal, and the black / green wire is the ground , according to the MY 95 manual.

hi , yes the engine light does come on, so it must have thrown a code, how can that be rectified?
ps, thanks for all your valuable i
nformation and help
paul

You need to get the code read. Here in the US, many auto parts stores will read the codes for free. It takes less than 15 minutes for someone to do it, so any mechanic with a code reader should be able to do it for not too much $$. Get the code number (like P-220). The generic descriptions that come up on the scanner may not be right for a Jaguar, but the number tells the tale.

thanks Ross, i really appreciate your help, without it i would have been running around like a headless chicken,
regards
Paul

Paul, you can get a code reader suitable for engine codes, for notalotacash. Mine's a bluetooth one that talks to my phone, and cost about £15!

P.S: it would indeed take about 15 minutes if you included 14.5 minutes for a cup of tea...