What Causes a spark?

[James.f]

What causes the engine to spark and fire up?

Coilpack
Ht Leads
Spark Plugs
TDC sensor

what else?

mine doesnt spark atall, yet its cranking over loads.

Help

 

[Budgie]

Petrol?

Done a compression test?

 

[James.f]

Ye have enough petrol

How do you do a compression test,

Mate of mine said Map Sensor, but dont kno if clio's have it or now

 

[Budgie]

Yeah, they do have one..

You need a compression tester.. About £15 from Halfords, iirc..

Have you tested all the plugs are sparking, too?

 

[Cooksport]

check there is power to the coil pack, and start eliminating possible faults.

 

[James.f]

Ahh, were abouts is this Map sensor located fella,

Iv pulled each Ht lead out and tested them, and theres nothing sparking,

Compression of what am i lookin for?

 

[James.f]

check there is power to the coil pack, and start eliminating possible faults.

Got one of them test pens which show a light when theres power, and it doesnt show a light, but the other plugs stuck on the same loom work:S

 

[Budgie]

Right, well that's narrowed it down..

As said, test the coil pack's getting power..

 

[James.f]

As previous post,

Everything else around it works, just seems to be no light on my test pen when i switch the ignition to 2.. you can sometimes hear the throttle body whinning,

 

[Budgie]

Hmm. Does the coil pack have it's own fuse?

Checked the wire's not broken anywhere?

Might be worth swapping the coilpack over, and testing with a different one..

 

[James.f]

Not sure, but before it wasnt doing nothing so the fuse's etc have all been checked and replaced if they were broken,

The wire from the coilpack is stuck to the same part off loom that feeds into the throttle body, but if it comes to it i might have to take all wires out again,

I still have my old coilpack, thinking that was the cause but it wasnt, then i was told TDC sensor, as that controls the spark to go in order ..

2months now without a car is preety shait tbh,

 

[Budgie]

Definitely..

Eff knows. I'm oot.

 

[Cooksport]

what engine is it?

 

[James.f]

172 engine

 

[Cooksport]

Rep? What exactly have u tried to do already.

 

[James.f]

ye rep,

Changed Ht Leads/Coilpack/Spark Plugs/Battery/TDC sensor.. then iv checked every earth wire is connected properly,

then iv tested each plug to see if theres any current to them, by using the pen tester, but nothing on the coil connector

Fuel pump primes perfectly, just no spark to ignite

 

[Cooksport]

I think there is a relay somewhere which operates the spark. (there is on the spaxo, im guessing now).

These are all guesses from different cars, but sometimes the ECU decoder will prevent a spark.

Get it into a garage if i was u mate.

 

[James.f]

I dont really fancy getting it into a garage straight away, as if its not what theyve done/fixed then it money down the pan. but il have to re-trace my steps again and go from there

cheers for the help fellas

 

[Cooksport]

Sorry i couldnt help more. Hopefully one of the Big cheeses will swoop in and tell u the problem

 

[James.f]

bump,

anyone kno? is it worth trying to replace the engine loom ?

 

[cliosportcraig]

By tester pen do you mean an inductance pen? Those pieces of s**t that light up when you rub them on your shirt? LOL

Get a multi meter and test for a voltage at the coil, remove a spark plug and plug it into the lead and place it close to the engine or anything earthed and crank the engine over, see if you have a spark (don't hold the actual spark plug)