Lost Spark

[Guest mark little]

Hi all, advice required as usual, for some reason the spark has disappeared from my Westfields crossflow engine. I've had it jacked up at the front for a few days while sorting a few things out, put it back down tonight and it won't start.it was running before I did this, checked the wiring all seems ok, anybody got any ideas.

 

Cheers Mark

,

[biksz]

daft question but you got fuel in it?

[Guest mark little]

Plenty of fuel, plugs are wet, engine's turning over but not firing, no spark at the plugs.

[sj-bradley]

Earth strap 'twix engine 'n car ?

 

Simon.

[agent_zed]

just having the same problem. i'm thinking mine is the coil not working as i have 12v at the coil + terminal with the ignition on. I did a resistance test and it was off http://www.international-auto.com/fiat-lancia-electrical-system/how-to-test-an-ignition-coil.cfm so have bought another.

 

oh i tested with a jumper cable from block to neg battery to be sure earth was ok.

 

i reckon i left the ignition on when i was working on it and burnt it out

[alantoon]

I don't know what distributor you are using but the plug on the Bosch has a tendency to fail. I replaced the plug after a similar failure .

[Guest Ian & Carole]

Back to basics,

1 points gap ?

2 condenser failed ?

3 L/T lead in the distributor snapped?

4 Have you got 12v at the coil ??

Edited May 23, 2014 by Ian & Carole

[steve in stockport]

the sparks probably rolled to the back while it was jacked up, try jacking the rear up and see if it rolls back into place!

 

seriously, have a good look round where you were working on the car for a dislodged wire or component, or jack the car back up again and see if anything gets trapped etc from things moving as you jack, other than that it's back to basics as Ian said

[Guest mark little]

I've found the problem, the positive terminal on the coil has snapped off, it looked like it was ok but it was only held on by the small wire inside. It's a new coil from Accuspark haven't had it that long and I have no idea what might have caused it, could some fault have blown it?

 

Cheers Mark

Edited May 23, 2014 by mark little

[HAWKNORTH]

If it had blown there would more than likely be some evidence :ie black marks from burning etc. Could you have knocked it while working on the car?. If you think it was faulty then try taking it back to the supplier. He may tell you to "go away" but its worth a try.

 

Dave.

[agent_zed]

now that Mark has located his lost spark. anyone have any ideas where my spark has gone?

 

So i tried a new coil and still no spark. It was all running a month or so ago an pretty much always started on the button. The leads, rotor arm, coil are pretty much new and had no signs of breakdown before laying up so i am thinking something more like a bad connection or something. I've got 12v at the positive terminal on the coil with ignition on.

 

I'm running the sierra ignition module the black one with the small heatsink on the back. The dizzy is the bosch one.

 

So from what i understand the dizzy should spin and the sensor turn the LT current on and off via the ign module, which then makes the HT spark. So there isn't anything else that is really needed to start the engine? is there a fuse that can blow?

 

Alan you mention a plug that might fail? which one are you thinking?

 

it has been out in the wet so i'm wondering if there is water somewhere it shouldn't be.

 

any ideas would be really helpful

 

thanks

[Bob Tucker]

Try WD40 all over everything...

[HAWKNORTH]

He means the car!

[agent_zed]

Hi so wd40'd everything (on the car) and did some more investigating.

 

So this is weird. I turn the ignition on and test the cable that i thought was the negative (black) and it's showing 12v on the multimeter. So i connect a small 5w lightbulb and earth straight to battery and the bulb won't light??

 

The positive wire (green) doesn't show anything when i multimeter it back to earth. I may possibly have got them switched around when i changed the coil the other day but the bulb should still light off the 12v off the first wire shouldnt it?? I tested the bulb and it lights fine on the battery.

 

I tried to check the resistance on the dizzy plug and wasn't getting a reading so i'm thinking the dizzy may be shot. It says to replace the entire dizzy if that happens. Should i?

 

any help much appreciated

[agent_zed]

well one bit makes sense now as this http://www.rodsnsods.co.uk/forum/tech-discussion/2-0-pinto-electronic-ignition-wiring-help-45829 says 'black-non fused ignition feed/positive side of coil'

which will be why the black is 12v but still doesn't explain why it doesn't like the bulb.