Help, I'm getting an inconsistent spark from my 2.1

[richardjay]

Hi all

My 1990 T25 2.1 wasser boxer is not sparking properly so sometimes runs and sometimes doesnt. Here are the tests i have done so far:

- I have put a new coil and new HT leads on

- I have pulled the ignition coil lead off the distributor, held it with pliers and earthed it to the engine. Result was very little (if any) spark. i reattached the lead and the engine still wouldnt run

- I then pulled the ignition coil lead off the distributor, held it with pliers and earthed it to the engine to chassis earth strap. Result was a better spark. i then reattached the lead and the engine then runs for a while.

I cleaned up the earth strap itself and now it looks a copper colour. I dont know if that is the proper colour or whether it is rusty which is preventing it from earthing properly.

my thoughts are there is a bad earth? but which one (are there more than one?). any suggestions would be greatly appreciated

thanks

Rich

[ermie571]

Hi Richard!

Welcome in!

Is your 2.1 running the injection system (stock) or carb (engine change jobbie)

Various earths need attention....battery, gear box and engine earths. All connections should be shiney...but beware of shiney ends and green corrosion behind spade connectors etc!

others with a good deal more knowledge will be along I'm sure

Emx

[mark]

^^^^^^^^
yes...... clean and gleam every connection

mark

[richardjay]

Hi, thanks for your replies.

Its the stock 2.1 injection.

i will get on with cleaning the earths - Is it better to just buy new straps or clean the existing ones?

thanks

Rich

[mark]

buy new.............and clean all the electrical connections.......they will be green.....use electrical contact cleaner and a tooth brush

mark

[itchyfeet]

looking at your origional question I wonder if the distributor cap and rotor arm needs replacing, if you changed leads and just removing and replacing king lead improved it then suggests that the action of doing this changed something.

It could be you disturbed a wire too, check the black 12V feed to coil as well, try a temporary 12V feed to the + terminal of coil from post in black box, this then bypasses the ignition wiring which may not be providing enough power.

[California Dreamin]

The copper braided cable you talk about might be 'tinned' which is something done to prevent/slow down the copper from corroding.
I would recommend that you add an 18 inch braided strap between the chassis (taken back to bare metal, strap attached and then rattle canned afterwards) and one of the starter motor bolts. As for 8mm eyelet one end 10mm the other.
http://www.ebay.co.uk/itm/18-Car-Earth- ... Swv-NWaFQw" onclick="window.open(this.href);return false;

Are you using original solid copper leads? others can be of the 'carbon impregnated) variety and easily broken by pulling.

Martin