Car not starting occasionally

[ANG355-SP20]

Every so often my car decides to not start.
It usually happens after I've been driving for any amount of time and the engine is completely warmed up.
I get back to the car within half an hour or just over, try to start the car and it just can't tick over, everything shakes.
Mechanics say they can't fix it because it hasnt happened to them to be able to see what the issue actually is!
It doesn't happen every time, just on occasion once or twice a fortnight.
It is almost impossible for me to get it fixed as I can't determine when it's going to happen!
People have suggested it could be many things but until it happens they don't know.
Last time at the mechanics they said it could be the camp shaft sensor or the crank shaft sensor (I think that's what they said)
Please let me know if I can't get it resolved until it happens to a mechanic!!

[phildough]

A lot of members have been having issues with their coil packs recently, I would start by having these checked.
If you were in QLD I would loan you one of my spare sets to test to see if this is the problem.

[BG1.8sp]

Yeah.... I have 2 sets of coil packs that I loan out to help people diagnose too.
If you are interested just shoot me a PM

[ANG355-SP20]

Can someone please explain what a coil pack is lol

[BG1.8sp]

Sits ontop of the spark plugs. SP20 runs 1 coil pack per 2 cylinders.
It's purpose is to basically amplify the spark.
So if they are dieing you will end up with a weak spark.

Probably the most simple way I could put it.

If you can wait until the next meet up I could chuck a set of mine in your car for a couple of weeks and see if anything is different.

[Cosmo Dude]

Originally Posted by ANG355-SP20

Can someone please explain what a coil pack is lol

Makes the spark plugs go spark which ignites the fuel in the engine.
It's what the coil does on older cars but because it's electonic the wires inside can break and come apart when hot. Lucky my MZR-CD does not have spark plugs

[ANG355-SP20]

Any thing else it could be, I'm sure the mechanics would have already checked the spark plugs

[phildough]

Its not the spark plugs we are talking about, its the coil packs on the top of them.
They are very prone to intermittent failure.
Here is a pic of what we are talking about.

[rodhog]

Highly likely on age - As said Coil packs. BUt it could be anything. Ideal situation to you replace all suspect old items until you find the problem.

wha'ts a coil pack well.

Older cars had a Coil- Creates the massive High volatage spark. - Distributor and then spark leads then the actualy spark plugs.

With Electronic controls and advance
they got rid of the Coil and had internal coils inside Distributors. Or in your case. A Coil pack - that is fired by the ECU. It creates the spark.

Now if it's not the coil packs- - which is highly possible.
It could be the crank angle sensor or camshaft sensor - varying on engine to engine.
Fairly reliable in 90% of Jap cars. Not so in say a Holden V6. Mazda's are fairly good.

I'd actually look next before that too a coolant temp sensor. If the coolant temp sensor is slighlty dodgy - it might not actually see a warm engine and either not give enough fuel or too much fuel on restart. Of course other things would suggest such a problem - like POOR fuel consumption and a very black exhaust tip.

Also - Air-flow metered car. Any cracks or leaks in your intake that open up after driving. Could cause and issue.

[ANG355-SP20]

It's a wonder, after 10-40 mins of waiting the car will restart as normal! It happened to me today I left the car for about half an hour n it wouldn't start, this time I had to wait 40 mins, other times as little as 10 mins

[Clean_Cookie]

Coil pack cools down and resistance lowers enough to allow a sufficiently large spark to fire... Maybe?