after i turn it on at the morning if i turn it off (sometime it turn off alone if i apply brake & slow down) the engine wouldn't start untill i keep it for half an hour.
i change the following & the problrm still the same:

• sparks (genuine parts)
• sparks cable (genuine parts)
• the electricity distributor (the other side of the sparks cable)

any one have idea what it could be?

 

You should really post a NEW thread, instead of digging up and old one, that might not be related. Also, if you have a 1998, and live in North America, you have a Discovery 1, and so you might have better luck in that section.

What have you checked? Do you have spark when it won't start? Fuel?

 

thanks jafer for replying, sorry i wasn't able to open a new thread (is their a section for the LR1?).
anyway their is spark & fuel when trying to start & it wouldn't start.

 

That would be the Discovery 1 part of the forum.

By has spark, do you mean that a spark plug attached to a spark plug wire, and laid against the exhaust manifold (metal) shows sparks when cranking?

By has fuel, does that mean you checked fuel pressue at schrader (tire) valve on fuel rail on passenger side of vehicle (assumes left hand drive)? Expect 32 - 34 PSI.

By won't start, does that mean starter engages, motor turns over (fan belt moves - starter doesn't just "spin freely"), but fails to run?

Your heat related won't start is frequently the crank position sensor, but that kills spark, usually throws no codes. You can spray cold water on it to test.

There is also a fuel temp sensor, which is involved on hot re-starts, but that is usually a summer time issue.

 

A common problem with thte DI is the ground cables from the battery to the chassis and the starter to the chassis frame conection. They will give intermittent starter problems.