Morris Minor Owners Club

After an 18 month slumber I tried to start our car today (it has been started or at least turned over a good few times in that 18 months).

Once it's started and able to idle without the choke (seems to need A LOT of choke to warm up) it sounds fine until you use the accelerator. If I put a bit of gentle pressure it's fine but anything more than a feather light touch and increase and the engine cuts-out. Sometimes it seem like it's cut out, but then when the accelerator is released it springs back into life. Is a bit like using the accelerator is starving the engine of fuel.

The float chamber is clean and the fuel pump is definitely working.

Before I start on one or the other, should I start by looking to the carburetor or distributor?

Is the carburettor piston rising and falling adequately?

How old is the fuel? If the fuel has been in the car for 18 months that may well be your problem.

As above - is the piston rising and falling easily - and put some engine oil in the dashpot chamber!

How would I check if the piston is rising and falling correctly?

There was oil in the dashpot, but I topped it up a little to be on the safe side. The battery has now died, so it's back on charging for the next round.

We put half a tank of fresh petrol in a couple weeks back, so that should be okay.

To check the piston in the carb is rising and falling with a clonk ( i.e. freely / not sticking ) use the tiny lift pin on the carb.
Externally , you are looking for what looks like a nail ,surrounded by a thin long spring 1 ", with a washer retaining it.
Height wise it will be " below " the domed piston chamber and between the main body and float chamber.
Bob

Ah, excellent, thank you.

It moves up about a 1/4" then becomes very stiff for the rest of the way. It falls fairly freely, but no clonk. The second time moving it up, straight after the first, moves all the way up freely, but then goes back to being very stiff the following attempt.

What should the next course of action be?

Test it properly with a finger - take the air cleaner off. With the damper removed (black knob on top) the piston should slide right to the top easily and fall with a clonk..... If not - strip the bell and piston off an clean them well - NO abrasives....

Thanks for the advice bmc. Just did it testing like you advised and it lifted freely and came down with a nice clonk.

I started the car again, got it warm and idling nicely and tried the accelerator. Again a gentle increase in pressure on the pedal and there isn't really an issue, but a sharp increase and it almost cuts out.

What should I be checking next?

Thanks again for all the advice so far.

I assume that is with the carb damper back in.... The mixture is too weak by the sound of things !

Certainly was I'll adjust the mixture and let you know how it goes.

bmcecosse wrote:I assume that is with the carb damper back in.... The mixture is too weak by the sound of things !

certainly sounds like it,screw the nut ,under the jet ,bottom of carb,right in then screw out counting twelve flats,this is the basic setting then in or out to get optiomum setting.

Thank you for all the help. I adjusted the mixture and the car is now running super smooth!! Now it's time to check the brakes and mot