No Spark

[WallerZ]

What sort of things should I be looking for when I'm not getting a spark? The loom abd coil pack all came off working but haven't gone back on working :/

 

Any suggestions?

[Pete Mar]

Check there is power to the coil pack, then check the signal to the coil from the ECU and if you have no luck there then try the crank sensor.

[WallerZ]

Ok, so after a busy weekend, I still haven't been able to get a spark. I believe I have power to the coil from the ignition, but nothing after the coil pack (newbie testing skills though). Would it be a safe bet that the coil pack is knackered (worked previously on the MX5) ?

 

I also believe I have a good earth connection from the engine...

[theduck]

How are you testing your supplies etc?

[theduck]

How are you testing your connections/power etc?

[steve in stockport]

Believing is not the same as knowing, get a multimeter and test continuity and power properly.

No reason why the coil pack should have packed up between running on the MX5 and fitting to your kit unless you've dropped it or kicked it round the garage, more likely a wrong/bad connection or a mistake in your wiring

[WallerZ]

Sometimes, belief is all I have! Haha!. I'm using a multimeter and I am getting readings for voltage around the place (whether I am testing it correctly is another matter). I don't think I am getting anything through the coil pack but to spend approx. £200 on something that isn't actually the problem is a cost I'd rather not have to take. Looking into it though, it may be the problem. How do I test the coil pack to see if it is the problem?

 

I am planning on spending all weekend on the car, so if anyone can pop over for however long, just to have a physical look at the car would be very much appreciated. Even just identifying the problem would be a huge help as this is the one thing stopping me from getting the car finished

[theduck]

Will see what I can do. You coming to the meet tomorrow? Might be able to drum up some helpers.

[WallerZ]

I am yes Well I had a little play last night, couldn't get any resistance or voltage through the coil pack. Had 12V through the wires right up until the pack itself then nothing. Not even when cranking the engine. Does that sound about right before I splash the cash on a new coil pack?

 

Rumour was on the Mx5 Owners Club forum that if the ignition was left on without running the engine, the coil pack would overheat and break, but was only a definite known problem on the 1.8 version. I have had it stood on the ignition without running whilst sorting the lights out....

[theduck]

Sounds more and more like coil pack

[Longboarder]

It used to be true and could still happen but unlikely. Easy enough to test a coil or coil pack. Just rig a 12v supply to the coil positive and a flying earth lead from coil negative. Lay out the plugs on their leads on a metal surface so the plug body is earthed. Now if you hold the flying earth to earth, the coil will charge in a fraction of a second and belt out a spark when you lift the earth away to break the circuit. You should see sparks at the plugs. This is what it should look like.

 

 

40,000 volts gives you quite a belt. Don't hold high tension stuff like plugs, leads, or the coil pack. Use rubber gloves, insulated pliers, rubber shoes, don't lean on the bodywork, etc or you may find yourself sitting on the floor, leaping round the garage or worse.

 

Nigel

[WallerZ]

I have tried earthing the body of the plugs directly but no success. I'm going to take the plunge with the coil pack and replace the plugs and leads too. It does look like its had better days and I'm not sure when/if they were last changed.

[Longboarder]

Rather than replace the coil on a guess I still suggest you test it in the way I have described. That way you will know if it is defective or not. What happens with the scattergun approach of just replacing things on a guess is that it provides you with no further information as to the cause of your problem. How are you going to proceed if you replace the coil and it still doesn't work?

 

Test the coil. If it's duff then replace it. If it works then you have discovered that the ecu is not giving a switching signal to it. You can then investigate why and the possible faults would have been narrowed down.

 

Nigel

[richardm6994]

Zach, I would seriously go with what Nigel has suggested before spending any dosh on a new coil.

[Tazzzzman1]

Hi Zach

 

As above mate. Nigel is the sparky guru for all things automotive.....

Once you narrow down where the fault is occurring then you can start replacing bits. But as I told you previously, I'd replace all HT leads as a matter of course anyway...