Tempremental Ignition System.

[davemar 16]

My Mi16 engine runs with the 8v ignition set-up, so while not perfect for the engine, is at least simple. Before I had my current issues with headgaskets and suchlike it did have a few failures over the past year with the ignition circuit just stopping for no obvious reason, leaving me stranded a couple of times.

 

Unfortunately it is still misbehaving itself after the engine rebuild (HG replacement at least). I've tried swapping the ignition amp and the coil, and tracked down a faulty ground connection which I fixed. But sometimes it works and sometimes it does nothing. I've stuck an oscilloscope on various places, and there always seems to be a signal from the distrubutor, and the sensor's cable is in very good nick. This signal disappears on the primary side of the coil suggesting the amplifier is at fault; but I haven't managed to probe the input signal from the distributor sensor while it is plugged into the amplifier when I've cranked the engine. I fitted a brand new amplifier today and while it ran well for half and hour, when I tried restarting it later on it stopped working again.

 

Given all there is to the system is a distributor and it's sensor, the ignition amplifier, the coil, and HT leads, plus the wiring and supply; there's not a lot to go wrong! I've even removed it and have it sitting here on my desk happily running with one spark connected to the coil while I spin the rotor arm.

 

Any ideas would be most helpful!

[welshpug 1,627]

i know its not much help but I find the later systems much simpler to work on, as there are even less components to fail in theory.

 

I had a similar problem with my 8 valver, I would get an intermittent non start problem, which at worst would make it cut out when driving, but only when coasting down or dipping the clutch in traffic.

 

I never did cure it and I eventually just dumped the whole management for Mp3.1, coilpack ignition