Help - Started (just) for the first time in 4 weeks

[Mikeoupe]

I just started the Chim for the first time in four weeks, it started fine so I left it ticking over whilst I moved the cars around and when I came back to it the revs were rising and falling (between 500 & 1500) and it was missing like a bugger!

I tried a few blips of the throttle in the hope of clearing it but it continued to miss, back fired a few times and was essentially not really responding to the throttle before it died. I gave it a few minutes to cool down as the manifolds had got extremely hot before trying again, it started right up but the symptoms were exactly the same.

Anyway after several attempts and half an hour it began to clear so I took it out for a drive which I thought would sort it out but I'm now left with a misfire, which is especially bad under load and worsens after I've given it any throttle ..

So much for a sunny Sunday drive.

Any thoughts what's going on anyone?

Thanks
Mike

[Blues]

I'd start by checking all HT leads, make sure none have "flopped" and are shorting across the manifolds. also worth checking stepper motor and cleaning it if required (this might cause the inconsistent idling, but don't think it can cause misfire).