Not starting, no spark, what to check next?

Deluks · 30 Jun 2015

Mazda 121 (aka Ford Festiva) 1990, 1.3 petrol, 58k

Old banger as such, but up until now very reliable. Driving on the motorway Sunday, and the exhaust starts popping, clouds of smoke, immediately pulled over turned off. Wouldn't re-start. Called breakdown for a ride home.

Checked it over yesterday. Was low on oil, engine is a bit leaky but no drips or puddles (Hadn't checked it for a few months, admittedly)

Camshaft was still oily so not completely dry. Oil topped up.
Engine turns by hand so not seized
Attempting to start sees the plugs getting wet so fuel is there
Air puffing out of plug sockets so compression is there to some degree.
(!) No spark when plugs held against block, no spark when HT lead tip held a few mm from block.

I realise many of these aren't 'proper' tests.

Possible ignition coil failure???

What next to check? I have a multimeter, less the skills to actually use it! There's also the black cylindrical condenser type thing in the ignition circuit,bolted to the side of the bay, I'm not sure what it does.
I'll put a pic up a bit later.

Cheers

Mursal · 30 Jun 2015

Would it have started to run on the oil fumes from the sump going into the inlet manifold to save the environment?
Did you stop it or did stop itself?
Would it have lost the run of itself, over revved, these are sure signs that it sucked the fumes out of the sump, and ran on them.

Anyway, you have petrol in the tank?
Plugs should be dry now if its petrol on them?
Put the spark plug sitting into the cylinder with the lead on, and go for a start. You will notice the fumes firing if you have a spark, just in case you missed it?

Click for your coil pack (I think)

Deluks · 30 Jun 2015

So here's a pic. The component centre right is the ignition module?

The cylinder marked D041 is the coil? Current thinking is that one of these bit's are faulty? How best to locate the culprit?

(Note: The blue fuse, and wire is for a dash LED, (fake alarm) which I have temporarily disconnected)

Deluks · 30 Jun 2015

Sorry, crossed posts there. Thanks for the reply.
I can't remember exactly what happened in regards to stopping, after the bangs I put hazards on, and pulled straight over to the hard shoulder, I suspect I was off the pedal and just coasted in using momentum, braked and then switched off.

Fuel in tank, about a third. Defo can smell juice when attempting to start. Replacing the coil is an option, but I don't want to spend money on it, and then wait 3 days for it to arrive, only to find out that it's something else. The 2 bits in the picture top right, for example. (Cylinder thing and control board thing)

Burnerman · 30 Jun 2015

D041 is actually the wiper motor....the ignition coil is directly underneath it.
John

Deluks · 30 Jun 2015

Yes John, that's exactly what I thought too

Ok, thanks for clearing that one up! So past the bit where the HT lead originates, is there much more I can check?

I have been reading up about coils, something about a test light which plugs in somewhere and somewhere to test for signal. Can a normal bulb and a couple of bits of wire be knocked up?

Burnerman · 30 Jun 2015

I'm a bit concerned about suggesting the coil - although that indeed is a high chance - just in case it's the immobiliser or whatever having a bad day,
However, unplug the thin wires going into the coil, and see if you can get a resistance reading between the terminals, as a base check.
John

Mursal · 30 Jun 2015

Or take the big lead off the coil and check like you did the plug leads. You might have issues in the distributor cap, where the one spark goes to each individual plug lead? If you find you have a spark out of the coil, take the distributor cap off, check the inside for cracking, where the spark can jump to the wrong cylinder and the rotor/ middle carbon contact for signs of failure?

Belle427 · 1 Jul 2015

Ive no idea how these are wired but if its a 2 wire coil i would expect one of them to have an ignition fed 12 volt supply and the other to be triggered by the ecu?
Dont even know if they used a crank sensor on these but basic wiring checks are the first place to start.

Deluks · 3 Jul 2015

OK, thanks for all suggestions so far. I won't have time to check this or the dizzy cap again until Saturday.
In the meantime I've ordered a new set of HT leads, as I don't know when these were last changed (if ever)

Had a quick squiz earlier...

Black plug has (from left to right) black&white striped wire, and a Green&Yellow striped wire. This wire goes into the loom.

White plug has a black&white striped wire, and a solid blue wire. This wire goes into the back of the dizzy (Crank sensor?)

What do I stick where, and what setting to set the multimeter at? Can I test this off the car, or does it need to be bolted in for grounding purposes? (No clue!)

The Coil is the same as this:

Deluks · 10 Jul 2015

Ok, to conclude.
Got an electronics whiz pal to take a look. He discounted the coil, so took a punt on it being the ignition control module that was hidden behind the plastic cover on the dizzy. These are supposed to be greased with heatsink paste, mine wasn't, so might have burned out because of that.

http://www.aahmotorsport.com/ekmps/...ier-j007t01571-72-75-md618293-j170-1443-p.jpg

New one fitted, with computer CPU paste on the back, she fired up first time. Another life lesson learned.

Thanks to all that chipped in.

Not starting, no spark, what to check next?

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