Bad running

[Hobbo]

Hi all, help needed with poor running, car starts o.k. but when acceleration is applied it pops/ backfires in exhaust, this is at standing position have not yet tried out on road. Have checked points, plug gaps all o.k. previous owner had set timing, have tried mixture control on carburettor but it makes no difference, plugs were very sooty  which points to I think over richness.  Any ideas, Thanks Mike.

[John P]

I'm certainly no expert on this but backfiring sound like over retarded ignition which would probably also help starting.

I have my timing set to TDC fully retarded but then I do have a DK4A distributor so advance is automatic.

[John Cornforth]

Hi Hobbo

I know I say this rather often, but a misfire under load is often a sign of weak ignition. This in turn is often due to a faulty condenser. I suggest trying another one, ideally one known to be OK, before going any further. Any misfire will tend to give sooty plugs even if the mixture is OK.

[Hobbo]

Hi thanks for the replies, undone the pinch bolt on distributor to adjust the timing distributor won't move, am I missing something, distributor is a DK4A.0 Cheers Mike

[Reckless Rat]

There is a screw on the dynamo housing below the pinch plate. Try loosening it. You may need a dumpy flat blade screwdriver to access it. There is also a vertical adjuster bolt that passes through the pinch plate into the dynamo body. You should loosen that too if you haven't got a manual adjuster.

[Hobbo]

Hi I can find a bolt which holds the pinch plate in position and a bolt in the dynamo housing but that's all. Undone the bolt holding the pinch plate but will still not move, haven't as yet undone bolt in dynamo housing as not too sure if I should will I upset something. Thanks Mike p.s. couldn't find a screw

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John have got new condenser on order will be here tomorrow Mike

[Reckless Rat]

Normally it is a screw, the end of which locates in a groove on the distributor, to allow it to rotate but not lift out of its housing. It may have been lost and replaced with a bolt. If so, it might be screwed in tight thereby preventing the distributor from rotating. If the pinch plate is loose and the adjuster bolt slack, it's the only thing that can be holding the distributor.

The pinch plate tightens onto the distributor body, not its housing. The adjuster bolt holds the pinch plate down to the housing and the side screw ( normally) prevents it from being removed. Loosen it and see what happens. There's nothing to lose.

[Hobbo]

Will have a go with that, there is a pointer fitted to the side of the distributor with a scale will see if that moves. Thanks

[Colin Wilks]

This photo of my DJ4 may help you visualise what's going on. The bolt you've not undone intrudes into the groove just above the pinch plate in the pic. It is there to stop the distributor rising up in its housing, but if the bolt is a bit too long it will clamp into the base of the groove and stop the distributor turning, which can mess things up if you have manual advance and retard.

Hope this helps.

[Hobbo]

Hi have removed bolt completely it is 5/8" long a 10mm socket just about fits it , distributor still will not move replaced bolt but will now only go partially in about 3/8" dare not force it or it will snap. Just noticed Colin's picture , the knurled nut with no 1 does not exist on mine. Can now see where this bolt goes, it is to stop up and down movement, will just try and move dissy up and down a bit to get it back in but rotation to advance or retard is rock solid. Will have a further look tomorrow and let everyone know what I find. Cheers Mike