Poor starting after a few weeks

[radioactiveman]

Hello

This may be something (or it might not be).

I've not driven my MM for a few weeks, but I thought I'd take him out yesterday for a quick trip around the block as I have an MOT booked soon. Plus, I rather enjoy the admiring looks of the townsfolk. Anyway.

When I went to start him he struggled a bit, quite shakey and as though he was struggling to find his rhythm. He began to settle and then died (sortof conked/petered out). This happened a couple of times before finally he was running as smoothly as usual.

I'm still not 100% sure he's running entirely correctly at the best of time, but that's probably another story

[ManyMinors]

You don't give a lot of detail. Is the car really an "MM"? How long has it been standing for - a few weeks, months, years?? Don't forget that modern fuel deteriorates pretty quickly and that can cause all sorts of problems as well as the usual ones

[radioactiveman]

Sorry, you're completely correct. When I said MM I meant Morris Minor!

It had been left for 7 weeks.

[simmitc]

Still a lack of detail and lots of possibilities, but a few thoughts to start with, plus some questions:

• Condensation in distributor cap

• Fuel pump diaphragm hardening through age and lack of use

• Fuel pump points dirty

• Head gasket starting to fail

• Stale fuel

• Piston in carburettor sticking

• Battery discharged (going flat)

When you switch on the ignition, does the pump immediately start to click and then stop, and then click a bit whilst the engine is running?
Does the engine spin over on the starter as normal, or does it sound a bit slow?
When the engine starts, is it running on all 4 cylinders, or does it start on say 2, and then pick up to 4?
How long after starting until the engine runs normally -= is it ever normal, or is it always slightly off and lacking power?
Was it running OK the last time that you used it, ie this is a new problem, or has it been developing over time?
Is compression OK on all 4 cylinders?
Is the radiator water clean and at the normal level?
948cc or 1098cc, and any modifications from standard?

[radioactiveman]

When you switch on the ignition, does the pump immediately start to click and then stop, and then click a bit whilst the engine is running?
Yes, the pump ticks for a bit and then stops then continues to tick occasionally once it's running.

Does the engine spin over on the starter as normal, or does it sound a bit slow?
It seems normal.

When the engine starts, is it running on all 4 cylinders, or does it start on say 2, and then pick up to 4?
I'm not 100% sure what that would sound like, but it's certainly possible. It sounds like I would expect that to sound.

How long after starting until the engine runs normally -= is it ever normal, or is it always slightly off and lacking power?
A minute maybe? I'm not sure if it lacks power as this is the only one I've driven. I don't think it feels any worse than when I first got the car.

This is how things sounded yesterday after they'd settled: https://www.youtube.com/shorts/G1yjUlrw4k0

Was it running OK the last time that you used it, ie this is a new problem, or has it been developing over time?
This happened the last time I'd not used him for a while. Before that things seemed fine.

Is compression OK on all 4 cylinders?
I'm not sure about this, I don't have a testing device.

Is the radiator water clean and at the normal level?
Yes.

[myoldjalopy]

You say: "I'm still not 100% sure he's running entirely correctly at the best of time, but that's probably another story "
Maybe not - if its not running correctly at the best of times, its hardly surprising it doesn't start easily after being left for a few weeks. Engine sounds OK to me from your video. Could well be condensation in the dizzy cap, but that is just one possiblility - as pointed out already. Laws of probability suggest it will be an ignition issue. Check all that over carefully (leads, connections, plugs, dizzy components etc.)

[svenedin]

Could be an ignition issue as previously mentioned. Could also be a fuel issue. Old fuel, limping SU fuel pump, crud in fuel system, sticking float etc.

[oliver90owner]

Simmitc has listed most of the necessary questions. I would add plug leads and caps.

Giving it a good service to manufacturer’s specification would likely provide an improvement?

[radioactiveman]

Thanks guys, I appreciate it. All good advice!

I tend to jump to worst possible scenario in my mind. I had some running issues just after I got the car (caused by my over enthusiastic choke use!) and I rather lost my confidence.

[svenedin]

If you leave the choke out too long the fuel/air mixture remains excessively rich. This can foul the spark plugs with carbon deposits which gives rough running. You can remove and clean your plugs with a wire brush and brake cleaner or if very bad you can replace the plugs. If not confident do one at a time so don’t muddle up which HT lead goes to which plug. In future push the choke back in as soon as the engine has warmed up.

[mowogg]

I am not sure how long you have had your car but the way I use the choke varys quite a lot in the colder weather. From cold I always start with full choke, but push it most of th way in when it starts in thr hot weather. After I drive it thr end of my road it goes fully in. This process takes longer in the cold.

As above you can hear when it's too rich. Thr ticknover is not even if it's too rich.

I don't think any car likes not being run for 7 weeks, but Minors are better this most in part due to the electric fuel pump

[Myrtles Man]

Thanks guys, I appreciate it. All good advice!

I had some running issues just after I got the car (caused by my over enthusiastic choke use!)

Did you carry out an oil change immediately afterwards? If not, you ought to crack on with it as over-enthusiastic use of the choke such as you admit to will result in excess petrol seeping down the bores and diluting the oil in the sump.

[svenedin]

If you remove the dipstick and have a smell of the oil you can tell if it smells of petrol. It should not smell of petrol.

[radioactiveman]

I did change the oil, however, I probably will again soon because a) it's quite fun b) I tend to only go out for short runs and I don't imagine it's getting that hot c) It can't hurt!

Mine seems to take a while to get fully hot. It's had a more modern-style radiator fitted, so I wonder if that contributes to keeping it cool.

[svenedin]

If the thermostat is not working properly it will lead to the engine taking a long time to heat up. When the engine is cold the thermostat should be shut so the circuit to the radiator is closed off to facilitate rapid warm up. Having the heater on during warm up will also slow the engine heating up. If in doubt the thermostat is a cheap part to replace but the thermostat housing being alloy can be a nuisance to remove and so the job is often neglected (you’ll need a new gasket too). It is possible to test a thermostat once it’s out but by the time you get to that point in the job it’s really not worth it and best to replace it.

[philthehill]

If you are going to fit a new thermostat first test it for correct function before fitting it.
As regards the thermostat housing - drill out the stud holes to 8.5mm and smear the studs with Copperease. Also do not use a cork gasket use the latest paper gasket. I would use no other gasket.
https://www.ebay.co.uk/itm/251750460431 ... R7L_qv6BYQ
Smear the paper gasket with grease, this helps keep the gasket supple and aides' removal at a future date.

Thermostat housing 5.JPG (1.32 MiB) Viewed 1392 times

The sandwich plate is fitted to allow a thermostat to be utilised. The 940 head as featured above does not have the facility to accept a thermostat. Fitting the sandwich plate gets around that.

[oliver90owner]

Can someone explain how ‘difficulty starting’ has metamorphosed into thermostat replacement, all in less than? I fail to see any real world connection.

[svenedin]

Can someone explain how ‘difficulty starting’ has metamorphosed into thermostat replacement, all in less than? I fail to see any real world connection.

The OP mentioned the car taking ages to warm up

[myoldjalopy]

Quite so - OP said his car "seems to take a while to get fully hot." So there you have it.....

[radioactiveman]

Often these threads do seem to meander a bit!

I will get my MOT out of the way (I don't want to completely break something before then), then (if I have any money left) I'll put on my big boy trousers and give the ignition parts a good service. I have spare points/condenser but so far haven't been brave enough to take the distributor out of the car.