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Weak Spark
xxx - 13/2/06 at 05:40 PM

Hi guys can I pick your brains again please...

Getting a really weak spark (sometimes nothing) from coil. I have got a new coil and still nothing. All wiring to coil seems ok and lead is new! Battery is ok, even tried jumping it from another car and still nothing.

Does the fact Im getting something mean that the dizzy and ignition module are working? Any way of testing these components?

Ive uploaded some photos of the system in my photo archive.

Any suggestions as to what to look into would be appricated as Im clueless!

Thanks

Colin


flak monkey - 13/2/06 at 05:50 PM

Have you had the distributor cap off?

Make sure all of the contacts are spotless inside, the ones with ali contacts are always corroding giving a crappy spark.

After that maybe try another ignition module.

David


minordelay - 13/2/06 at 07:12 PM

You havn't said what the engine/system is it could be points, condenser, rotor arm, cap, ballast resistor etc etc.

Have you got a good 12V supply to the coil when cranking, and are the points/dizzy giving a pulsed earth to the coil?

That should give you something to go on.


britishtrident - 13/2/06 at 07:28 PM

The coils for Ford electronic distributers are different from points type ignition --- from the photos I can see it isn't an OEM Ford coil. Get the coil of an Escort Mk3 and its wiring.

Metro coils are also suitable.

Also check you have got a ballast ressistor wired in to the feed for the coil.


David Jenkins - 13/2/06 at 07:58 PM

First of all - you don't say what engine you've got!

If it's a x-flow, read on...
You mentioned an ignition module - is it a Bosch dizzy? If so, it works at 12v, doesn't need a ballast resistor, and should have a 12 coil designed for electronic ignition.

How do I know? Been there, done that!

If it isn't a X-flow... ignore me.

David

[Edited on 13/2/06 by David Jenkins]


minordelay - 13/2/06 at 07:59 PM

Sorry I never looked at the pics, at trick that I was shown years ago might be worth a try.
With the module removed from the dizzy but with the wire connected short out the two contacts on the module with a wet fingertip (ignition on) if you see a spark dizzy is probably at fault.


xxx - 13/2/06 at 08:28 PM

Thanks for the replies

Sorry its a 1300 xflow which has been converted to electronic ignition. It has been working fine with this setup but is now refusing to work!

Ive had the cap off on more than one occasion and it seems in good condition.

Im pretty sure it is a bosch dizzy and it definatelty is 12v!

I can get more pics if you want to clarify anything!

Thanks again!


David Jenkins - 13/2/06 at 10:36 PM

OK - if it's worked before then the basic setup must be correct.

One thing you could try is to take the electronic module off the side of the dizzy and make sure that the mounting surface is nice and clean. Then you can smear some heat-conducting compound between the two before refitting. I got a little tube of compound from Maplins, but any place that sells build-it-yourself computers will have something suitable (it's what they use for putting between the CPU and its heatsink).

A cooked module used to be a common cause of failure in the past, apparently. In the worst case, you might need a new module, but I don't know how you'd prove it's good or bad.

David


[Edited on 13/2/06 by David Jenkins]