Morris Minor Owners Club

My 1958 saloon has always had the following problem.

It starts fairly easily, but on one cylinder, adds another and so on over a period of about 90 seconds and then is fine for the rest of the day. It only happens when it is cold, worse the colder and damper the weather. The period of time, a day, a week etc makes no difference. Starting it with or without choke makes no difference. The choke does have an effect of the engine when going, so I assume it's working.

Trying to add accelerator kills the engine. Adding accelerator very slowly will git it going.

I replaced the head to make it unleaded, but it was just the same before.

When going it is extremely reliable. I cannot remember the last time it broke down.

Any suggestions?

The engine is extremely unlikely to be running on 1 then 2 and so on, have you actually found this out or are you assuming it's doing this? If it could run on 1 it would be so rough it would shake the car apart.

Put a colour tune in each plug hole and start it, if you only have one, do it on a different plug hole every time you start from cold, hey presto, your missing pots are revealed and you can begin to work out why they are missing.

Al

Well I'm assuming 1 then 2 etc. Yes it is very shakey when accelerator used. All is ok upon any warmth getting into the engine.
Sounds like a badly running moped for as I say about 90 seconds, then ok.
If I try to drive, well it will, but no power until a little warmth there (250 yards)
It creates the same effect when warm if I remove leads then ok when I replace them
Thanks

You say it doesn't make any difference if the choke is on or not, it makes me wonder if is it actually doing anything when you pull the choke out? Can you see the spindle turn on the carb as you pull the choke?

I suggest new rotor arm + dizzy cap + HT leads will help considerably.. Especially as you say it's worse in damp conditions. But it could also be (as mentioned above) that the 'choke' isn't actually doing anything at the carb - so it is well worth looking into that.

Possible spark plugs. Have you checked, and/or cleaned, and /or gapped the plugs?

Plugs leads cap, arm etc all new

I've had the car 15+ years - always had the problem, both before and after sorting the head. (head is good, gas tight, etc)

Might suspect the choke which I haven't checked. What would I be looking for?

The damp, doesn't stop it starting by the way. It will idle, but any application of throttle kills it in the 1st 30 seconds. You can gradually add throttle after that. That's the point is sounds led than 4 cylinders. Give it 2 minutes, it's fine.

To check the choke is operating get someone to pull the choke knob in and out while you watch at the carb end. The outer cable is held in place but the inner cable should be moving and operating the spindle on the carb. If the cable isn't moving at the carb then it's broken, if it is and its moving the linkage and spindle OK then the problem could be internal to the carb. It might be easier to take the carb off the check that the choke flap is moving but you may be able to see it by taking the air filter housing off, lift the carb piston and look inside while you assistant pulls the knob. Probably need a mirror to see inside doing it that way.

it may be simply carb adjustment,assume you know how to check. ,but if not when fully warmed up.lift pin on side of carb slightly,not all the way up ,and hold it there,revs should rise slightly then fall back if setting is correct,if the revs stay up, too rich, screw jet up(in) a touch and try again,if revs drop or engine stall too weak,screw jet down(out) and try again. If you totally mess it up. Screw jet all the way in then unscrew 12 flats ,basic setting then do the same as above.

Also try spraying WD40 over the dizzy cap and HT leads prior to starting it on a cold, damp morning.

It sounds like the HT is arcing somewhere; lift the bonnet with the engine running on a damp, dark evening and see if there's any stray arcing going on.

To report the solution... It was a malfunctioning choke.
New cable and easing off the mechanism was ceased.
Reset the mixture.
Wow it's lots better.

Excellent
Thanks for getting back with the cure

That was mentioned several times.....ages ago! But well done getting it sorted.