Car wont start :(

[Insurgence]

Parked car and car wouldnt start again when i got back!
Keep in mind car was working fine previously (had some ignition issues - car would start rough and I could always fix it by removing and replacing one of the ignition wires at the coil pack end)

Initially thought it was coil packs, but after switching those no avail!

I think the most likely explaination is (Haynes)
- Loose or damaged wiring in ignition system
- Faulty Camshaft Position Sensor


I dont think it is:
- Fuel tank empty (not poking fun at anyone, though it is the first item in the Haynes manual )
- Battery discharged / Battery terminal loose/corroded
- Low cylinder compression
- Water in fuel
- Dirty injectors
- Damaged spark plugs
- Timing belt

Any suggestions? I'm going to test the ignition system to see if the spark plugs are sparking, then take it to mazda.

The spark plugs wouldnt spark if the Camshaft Position Sensor is faulty yes?

[ampz]

no.

The cas tells the ecu the engine is turning (and what point in the cycles it is at), so if it is somehow not working (have you checked the ignition fuses? i never know which one it is so i pull them all out one by one and check) there will be no spark.

IF checking fuses (both inside the car and in the engine bay) doesn't find a solution, see if you can hear the main ignition relay cut in (click) when you turn the ignition key.

If the relay is also good (check to see if it has the same base as the horn relay or a/c relay for example, swap them and see if the accesory still works) then i woulg be looking at your ignition switch/barrel/key thing.

Try bridging the back of the ignition switch (hotwire the car) and see if it starts, it could be the switch is not supplying power to the ecu (and hence coils) during crank.

I none of the above checks out....
Then i have no idea

[bigdog]

Sounds like the ignition relay - has happened to a few cars on the forum. Bit of a bugger to remove - see this thread:

http://www.aus-cartalk.com/viewtopic.php?t=27337

I keep a spare in the boot just in case - you're welcome to borrow it if you want (currently at home in Warrimoo, but i could meet you somewhere if needed).

[StanTheMan]

If a car doesn't start......have you checked the basics?

no point going all complicated. Yes it could turn out one of the things you suspected.
but if you're looking for ideas...... how about the basics don't chuck a boagsy


OK you have petrol in the tank.....
what about the cylinders ?
Spark?

[Insurgence]

thanks for your advice guys!

i'll try some of the things suggested before getting it towed

i was actually wondering how i can tell if its a relay. cos its not like the relay can tell you if its broken!

[JBT]

Plug leads?

[bigdog]

My spare relay is at North Rocks (work) now if that helps...

[Steampunk]

Lateral thinking, anything in your car drawing a lot of power which is accidentally left on or has shorted creating a constant circuit?
Audio amp/head unit maybe?
Even though you may not think it's the battery, it may be something internal, when she does turnover, does she crank as good as usual?

[Insurgence]

Hey guys!

Cos i can get spark on both coils.

ampz - looks like it wasnt the ignition after all!

bigdog - does that relay affect the fueling?

also i dont think the \"buzz\" from the fuel pump is coming on when i put it on ignition?

JBT - i dont think its the leads cos they were always working fine!!

1red5 - i think it is cranking ok, i think if it were draining it would be unable to crank like it does now.

[Steampunk]

Did you by any chance see any of these lurking about recently?

[JBT]

also i dont think the "buzz" from the fuel pump is coming on when i put it on ignition?

Ahah! Try shorting the FP and GND connectors in the diagnostics box and turn the ignition on. If the pump works OK, you may have a dodgy relay.

[Insurgence]

JBT - quick response!

/runs off to find some aligator clips

B1 are you thinking what I'm thinking?
B2 that depends what you are thinking

if that is the problem can i just short those two pins and drive home? or is that an all time bad idea?

[JBT]

I think it will work as a \"get me home\".

All you need is a small piece of wire - an unfolded paper clip or similar will do it. You have to wedge the wire into the diagnostic box connector points.

[ampz]

Are you Sure you have petrol?

[Insurgence]

lol i wish it was petrol..
how does one check if fuel guage isnt working ^_^

1) when i pull main relay, it makes no difference (car still cranks but no start)

2) it appears the main relay works (i used 12v from my computer and it bridges the other two terminals)

3) i could not hear any fuel pump still.

4) tomorrow will be fuel pump relay day.