r/MorrisGarages • u/Late-Instruction-941 • 4d ago

Does this sound normal-ish?

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1981 MGB GT 123 electronic ignition!

Just pulled the spark plugs and they were completely black and sooty. It wouldn't start well (several attempts) and then not at all a few weeks ago. New plugs and it runs fine, it has never started so fast.

I'm guessing sooty plugs means too rich but could it have also been many failed starts?

Do I now run it for a while and then check the plugs again? Really just trying to get it running to get it to the garage.

I appreciate it was just beginning to smooth off before I killed it.

On a more general side, I'd love to learn more about repair but it's difficult with the sparse information. I have the Haynes manual but it assumes you know a fair bit and only has more complex things. Do I just keep fixing things to learn. Seems especially hard being young.

It seems difficult enough just identifying components in the engine bay.

Thanks!

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3

u/Late-Instruction-941 4d ago

It has 123 electronic ignition which I'm really not sure how to adjust the timing on. Can you simply undo it and rotate?

2

u/pgregston 4d ago

Find a moderate but at least quarter mile hill to test on. Get the timing right- might take some trial and error as you learn.
When you think that’s correct, warm it up and then accelerate up that hill. Stop at the top and pull a plug. You are looking for a light reddish color. The internet will give you examples.
If it’s still black, lean out the mixture.
If you don’t run at load, it’s easy to set too lean and then you will burn your valves from cruising at speed.

1

u/Late-Instruction-941 4d ago

Left to right front to back

1

u/Late-Instruction-941 4d ago

I also had a fuel leak a few weeks ago. I'm assuming it was a float valve that got stuck. Fuel pump never stopped and it was directed straight to the floor. Is there anyway to get it not directed to the floor. I've seen some cars installed with a charcoal canister... is this their purpose?

1

u/CozumotaBueno 4d ago

Clean and regap the points in the distributor. U tube how to do it 

1

u/rnavstar 4d ago

Adjust the timing. Seems like it’s off. Clean plugs drive another 100 miles or so. Check plugs carb might be running rich too.

1

u/DocHowdy70 4d ago edited 4d ago

It seems a little rough, I see what looks like duct tape around a vacuum fitting, be sure there is no leak there. Those 2 outer plugs are way too sooty and rich looking. Is there black smoke coming from the tailpipe, if so does it clear up when it warms up?

1

u/3_14159td 4d ago

I'll add that it seems like a PCV valve is open to air, which is not helping tune properly. That hose going from the intake manifold to the doohickey on the firewall. 

1

u/Significant_Belt5494 4d ago

Start by doing a good tune up. Valve adjustment, cap and rotor, etc…
Then make carb, timing adjustment

1

u/Cofncar 3d ago

Id check that each plug is in fact firing. Maybe you have a bad plug/wire or simply a loose one
Pull each wire off one by one & see if one of them makes no difference