Re: 1984 volvo penta qa125a no spark help
does the hot spark points mean you have done away with the condensor - i'm not familiar with the brand (UK).
if not - then run a jumper lead direct from the 12v of the battery to the +ve of the coil
then take all wires off the -ve side of the coil - EXCEPT the one from the points.
Now rotate the engine until the points are closed - and use a plastic tool to open the points - if there is a massive arc (spark) then change out the condensor(capacitor)
If it looks alright - minimal arc - then put the dizzy cap back on and check if you have a spark with the temporary jumper lead in place (the jumper you made from the battery to the +ve of the coil)
if you now have a spark then you know you have an issue with the power supply to the +ve of the coil.
if still no spark suspect coil. with the 12v jumper still on the +ve terminal of the coil, set up a jumper wire from the -ve side of the coil and hold it on a good earthing point on the block - use insulated (rubber handled) pliers. When you pull the wire away from the block (1/4 inch) you should get a spark. If not bad coil.
***DO ALL OF THE ABOVE FAIRLY QUICKLY - OR REMOVE JUMPER FROM COIL IN BETWEEN TESTS - DANGER OF OVERHEATING COIL - AND REMOVE THE BATTERY END SO YOU DON'T HAVE A LOOSE LIVE WIRE FLOATING ROUND THE ENGINE BAY HUNTING FOR EARTHS
***
can't see how changing a distributor would solve a complete 'no-spark' situation to be honest.
a distributor simply does just that - distributes the spark to the correct leads/plugs at the right time via the rotor arm.
If you take the breaker plate off the distributor to reveal the mechanical advance mechanism (springs and weights that extend centrifugally to advance timing with rpm) - and confirm that the weights are moving freely and both springs are in tact and in place, give it a clean up and away you go - put it back together.
distributors only really need changing out when the cam gets excessive play and timing is all over the place as a result.
good luck
adam
