No spark from Plug?



Ive got a Daihatsu Fourtrack 2.0l Petrol on a 1985 (C Reg.)

The problem i have is that from the plug numbered 4 on distributor cap i am not getting a spark so the engine is only firing on 3 cylinders!

To try and fix the problem i have bought spark plugs, HT leads, distributor cap and rotary arm.

I have tried all the leads and plugs in different orders but still no spark from the plug numbered 4 on the cap?

Any info or advice would be grateful because im all out of ideas.

Also just out of curosity what leads from the cap go to which plug so i can check that they are all in the correct order.

Is it possible that the shaft

Is it possible that the shaft in the centre of the distributer has a lump out of it, or is warn. This could couse the points not to open, thus spark? Not something I've heard of, but just hypothasising.

Any veiws expresed in this thread by me are purely from my own experience, and (sometimes) falible memory. Hope my comments help, but please don't take them as gospel.

What about the spark plug cap?

Try removing number 4[faulty] spark-plug cap so you have just a wire at the end. You might need to insert a metal nail/spike into the cable so you have a continuity. Hold the cable with insulated pliers. Start the motor and whilst engine is running hold the bare cable onto the engine [earth] and test for a spark. If it sparks then renew the spark-plug cap.
If that fails to spark then that remove the distributor cap. Now use a test meter down each cable and test for continuity from the cap's electrodes to the spark plug electrodes.. I very much doubt if the fault lies within the rotor-arm or contacts.



Ive decided that the problems lies within the distributor im guessin the points are not sparkin right.
Im not sure what a good shaft should look like and if it is worn.
I did take the shaft out and fiddle with it but still need to know what order the HT leads go back on the spark plugs from the distributor.