1256 misfire

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1256 misfire

Postby Wyke » 18 Jan 2006, 22:12

My daily 78 started to kangaroo a bit last week.
I did a points, cap and rotor renewal as they looked a bit worn ( 34k car )

However - now no spark at num 2 lead. Checked plug and lead.
ticks over lumpy and revs but no power and it is just num 2 !!!

Replaced cap and rotor and changed leads around and no spark across air gap when I remove 2 lead from dizzy ( which is what the other leads do ).

Does widening points gap help ?

Could it be play on shaft - for a 34k car , it would seem strange.?
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Postby chris(not) » 18 Jan 2006, 23:38

Sounds like the dizzy cap (top not capacitor) is tracking from no. 2- have a close look inside it with a bright light and see if there's any sign of a whiskery blackened line from the no. 2 terminal. If there is, you can fix it temporarily by scraping away the carbon, but a new cap is the real answer.

It might just be condensation if you're lucky...


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Postby Herbie_Flowers » 18 Jan 2006, 23:40

did you change the condensor?
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1256 misfire

Postby Wyke » 18 Jan 2006, 23:51

I changed the dizzy top and the rotor arm.
I cleaned up points and put back. I did not change capacitor. Reset points and static timimg.
Swapped leads 2 and 3 and problem sticks with number 2 cylinder.

Help !
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Postby Neilyman » 19 Jan 2006, 00:07

Dizzy bearing I`ll bet!
Had the same thing on mine a while back, changed the dizzy `cos I had one lying about....problem solved.

The spindle was running off centre & was totally missing which ever contact it was , can`t remeber. Try a `side to side` wiggle of the rotor arm from contact 2 to 3 opposite, it shouldn`t have any `play`.
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1256 misfire on 78

Postby Wyke » 19 Jan 2006, 00:26

Yes may be . I ran out of daylight on sunday after lots of messing. Don`t have a dizzy lying around and on a 34k engine I thought it was unusual.

Can adjusting gap help ?
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Postby Neilyman » 19 Jan 2006, 02:14

Nah, it`s the gap between the rotor arm tip & the contact in the cap that`s too big & you can`t adjust that.
It can also affect the points `cos the cam may not open the points enough for number 2....widening the gap `may` help as a short term, get you home measure, but the motor will run like a dog......dwell angles etc.

If there`s play in the spindle, change the dizzy....I might have a spare if you`re stuck, not sure though.

I changed my dizzy at 45k!
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