MK1 missing - Fuel or Ignition?

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camstevens
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MK1 missing - Fuel or Ignition?

Post by camstevens »

Hi All
My MK1 has started an unusual missing charaterisic of recent. My distributor unit has new base place, condenser, coil, cap and points. Logic would steer me towards suspecting the ignition circuit, however the only item that makes me suspicious is the "new old stock" Indian MA6 knock-off, which appears to have been around the warehouse traps for years ( and a few little dents which makes me nervous). I actually bought one off these previously, and I think it was failed in the box (leaking oil, etc , etc).

I started suspecting fuel as the missing tends to happen after about 10 mins running (which could also point to a dodgy coil) but tends to abate back a little when engine is warmer. The missing occurs when accelerating under load, is still preset at higher revs, but lessens. I understand a coil would be worse at higher revs? It's not one cylinder, but all 4.

Anyway, the missing seems very fuel-oriented at times. Aso at times the it unexpectedly idles at high revs suggesting fuel/air entering somewhere......last time it did this I fiddled/giggled the bi-starter lever and the revs instantly dropped to normal, and upon return from Kempton Park she totally behaved and ran like a clock. ...so I think I might be onto something. The core of the AHD was completely reconditioned, so all in good condition, but no work was done on the bistarter.......please see photos. Does anyone have experience with bistarters allowing air/fuel to enter the carb throat die to some kind of sealing issue? Please see photos.....the aluminium seal surface looks a little ratty.....I wonder if a piece of aluminium has picked up and held the bronze seal plate off the carb body? The bronze plate looks fine, but I also wonder if the pocked aluminum surface is allowing fuel/air to pass to engine?

Regards
Cam

PS weirdly I also think the Bistarter detent plate (with grooves for the spring/ball) seems to be back to front......there is not detent slot to hold the lever in the fully off position. Due to this I also suspect the lever has been "wandering" a little.
Bistarter carb body seal face2.jpg
Bistarter carb body seal face.jpg
Bistarter brass seal face.jpg
JohnnyBeckett
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Re: MK1 missing - Fuel or Ignition?

Post by JohnnyBeckett »

hi i would try the new condenser i fitted new points and condenser for my friend and it run bad i put back the old condenser and it runs ok now there is a lot of copies around, but now i have got electronic ignition and fitted it for him and it starts and runs a lot better :D 8-)
camstevens
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Re: MK1 missing - Fuel or Ignition?

Post by camstevens »

Thanks Johnny
I bought the condenser from Holden's here, so I'd hope it's genuine. But who knows. I am sorely tempeted to put an Accuspark unit on plus decent coil/cables but would prefer to pinpoint first (perhpaps I'm being idealistic). In electronics they used to call it the "left to right" method....keep replacing stuff until it works :D

Cam
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paul.jameson
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Re: MK1 missing - Fuel or Ignition?

Post by paul.jameson »

Check the strap which runs from the points round to the stud for the lead to the coil. I had the stud come unsoldered on my first Healey and it took me ages to find - but only a few minutes to fix by re-soldering.
Paul Jameson
35 LG (project), 37 RH500, 52 ex ISDT KHA, 54 KH(A), 75 Healey 1000/4.
Former Machine Registrar & Archivist, General Secretary and Single Spares Organiser (over a 25 year period).
Now Archivist (but not Machine Registrar), Gauges and Clocks Spares Organiser.
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