73 Mini

Started by MiniDave, November 03, 2016, 04:19:39 PM

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MiniDave

This car still has running issues....

When he first got the car it had hot starting issues, since then we've replaced the plugs, coil, plug wires and put in a new MiniSpares pointless distributor. It is not ballasted - but gets a solid 12V+ at the coil and at the dist. it now starts perfectly when hot or cold but.....

It starts instantly when dead cold on the choke, and idles just fine but when you try to drive it, it runs like crap, misses and sputters and will hardly pull itself. As it warms up it runs better and better till when fully warm it runs fine, pulls strongly and so on. We had it on the dyno at Prathers and the mixture was dead on, we made no changes to either the carb or the timing. I have checked the choke o-ring and it looks new, the carb is not new but it's as clean as new, including the piston and dome.

I feel like the problem must still be in the ignition circuit rather than the carb as it runs well and the dyno said it was doing all it should....about the only other thing I can think of is that maybe the points eliminator kit is not set right, but I don't understand why it runs right when warm, it should be the other way around  if that's the issue.

Anyone have any good ideas? or bad ones?   ;D
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

MPlayle

What sort of vacuum or mechanical advance does the distributor have?  Could it be sticking until warmed up?

If it has a vacuum advance, is it connected properly at the carb so as it does not get too much or too little vacuum when cold?


MiniDave

Brand new vacuum advance along with the brand new dizzy, works fine - showed the proper advance on the dyno (warmed up of course) but I don't know why it would stick when cold.
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

MPlayle

My thoughts on it sticking when cold was: if slightly greased inside, cold grease might be stiff and not allowing proper advance - the grease may soften enough when warm to permit proper advancing?

Granted, it is a total guess on my part and just as likely to be completely off base.

I have heard of coils giving issues, but that is usually when warm.  You are describing just the opposite.


MiniDave

Quote from: MPlayle on December 23, 2018, 02:58:37 PM
I have heard of coils giving issues, but that is usually when warm.  You are describing just the opposite.

Exactly why we tried another known good coil....
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

94touring

The removable wideband would come in handy to check fueling.  Clogged filter?

MiniDave

When we had it on the dyno it was perfect, it hasn't done 20 miles since then. I don't think it's a fueling issue....
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

MiniDave

One thing I forgot to mention....the tach isn't working right now either.....it reads 0 at idle and when you rev it up it only goes to 1-2K. another reason why I think the problem is electrical. It worked fine before....yes I disconnected it to see if that was the issue with the poor cold running, no improvement.
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

tsumini

I've had the same problem with my 60 Austin 850 with electric Fuel pump. I wrassled with it for a long time when initially getting it running.Finally got the timimg right with new ignition parts. But it stilldoesn't start cold worth a sh--. but warm it runs great, good throttle response puls good etc. again without dyno.Advance is about 30 degrees IIRC at WOT. Starts great when warm. I had some trouble setting richness at idle. The pin to raise the damper to set richness is stuck (down) so kinda had to guess.
oh yeah, That was at 8300 ft elevation, now its 400ft so may have to tweek something.
i'm not help

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