Series 3 which lead to which spark plug?

85Santana3 · Aug 27, 2020

Hello everybody
I have checked the manual and many videos on youtube as well as photos of different Series III engines. Strangely enough it seems like different dist. cap leads go to different spark plugs in different photos! There was no photo or guide in manual (at least I did not find any).
what is the correct order?
thanks in advance

Marmaduke · Aug 27, 2020

85Santana3 said:
Hello everybody
I have checked the manual and many videos on youtube as well as photos of different Series III engines. Strangely enough it seems like different dist. cap leads go to different spark plugs in different photos! There was no photo or guide in manual (at least I did not find any).
what is the correct order?
thanks in advance

This is mine...

Extreedoc · Aug 27, 2020

Firing order is 1,3,4,2. Distributor rotates anti-clockwise so if you look at Marmaduke's picture you will see that his is wired up correctly. If the distributor has been fitted correctly, the number one tower on the distributor cap should be the one nearest to number one cylinder as Marmaduke's is.

85Santana3 · Aug 27, 2020

Thanks guys.
My truck's engine is running very badly lately. Lots of black smoke, puffs and strange noise and as of yesterday lack of power as if 1 or 2 cylinder were not working.

After your answers I opened each spark plug one by one and checked them. They are all black showing bad burning, but they spark regularly. So all cylinders are firing (right?) then why is truck so low in power? I played with the two screws of carburetor, not much changed.
I checked the oil there is no sign of water in it (checking for blown top which could be cause of lack of power) there as no water in oil.

One thing I observed. When I removed the second from front spark plug engine started with difficulty and stayed on with difficulty, but when each of the other sparks was out engine started easily. Does these signs tell you anything?

Marmaduke · Aug 27, 2020

85Santana3 said:
Thanks guys.
My truck's engine is running very badly lately. Lots of black smoke, puffs and strange noise and as of yesterday lack of power as if 1 or 2 cylinder were not working.

After your answers I opened each spark plug one by one and checked them. They are all black showing bad burning, but they spark regularly. So all cylinders are firing (right?) then why is truck so low in power? I played with the two screws of carburetor, not much changed.
I checked the oil there is no sign of water in it (checking for blown top which could be cause of lack of power) there as no water in oil.

One thing I observed. When I removed the second from front spark plug engine started with difficulty and stayed on with difficulty, but when each of the other sparks was out engine started easily. Does these signs tell you anything?

I'll be honest I'm fairly new to petrols but when was the last time it had new leads, points and plugs? Which carb have you got?

DanClarke · Aug 27, 2020

New plugs, leads, dizzy-cap replace the condenser, set the points up with a voltmeter or a bulb to watch for static timing and look for vacuum-advance with a strobe-light maybe?

John S · Aug 27, 2020

And clean the choke jet in the carburettor. What type? Blow the valve clean and remove any carbon crude.

85Santana3 · Aug 28, 2020

carb is zenith 36 and was rebuilt a year ago although since then it never ran properly! all other stuff are a year and half to two years old (spark plugs, leads, cap, ...). I will change everything to see what difference it will makes. It is cheaper than letting the mechanics do it.

DanClarke said:
set the points up with a voltmeter or a bulb to watch for static timing and look for vacuum-advance with a strobe-light maybe?

Dan could you pls explain a bit. (or maybe a link to an article or video) thanks.

Marmaduke said:
I'll be honest I'm fairly new to petrols

I had a 2004 Jetta diesel, you just reminded me of the beautiful smell of diesel burning in cold winter mornings

Marmaduke · Aug 28, 2020

85Santana3 said:
carb is zenith 36 and was rebuilt a year ago although since then it never ran properly! all other stuff are a year and half to two years old (spark plugs, leads, cap, ...). I will change everything to see what difference it will makes. It is cheaper than letting the mechanics do it.

Dan could you pls explain a bit. (or maybe a link to an article or video) thanks.

I had a 2004 Jetta diesel, you just reminded me of the beautiful smell of diesel burning in cold winter mornings

Nowhere near as good as bringing back fond memories of putting your head into the cab and smelling petrol

Or when growing up and walking into the garage where my old mg or later on cj7 were parked and smelling oil and petrol

Turboman · Aug 28, 2020

85Santana3 said:
Thanks guys.
My truck's engine is running very badly lately. Lots of black smoke, puffs and strange noise and as of yesterday lack of power as if 1 or 2 cylinder were not working.

After your answers I opened each spark plug one by one and checked them. They are all black showing bad burning, but they spark regularly. So all cylinders are firing (right?) then why is truck so low in power? I played with the two screws of carburetor, not much changed.
I checked the oil there is no sign of water in it (checking for blown top which could be cause of lack of power) there as no water in oil.

One thing I observed. When I removed the second from front spark plug engine started with difficulty and stayed on with difficulty, but when each of the other sparks was out engine started easily. Does these signs tell you anything?

I wouldn't assume that because there is no oil in the coolant, or vice versa, you don't have a blown head gasket.
Land Rover engines don't often blow like that. And even if your head gasket is fine, you could have low compression for other reasons.
So in addition to checking all the electrical and carburretor stuff, as suggested, set the tappets.
And if none of that helps, get a compression test.

kermit_rr · Aug 28, 2020

85Santana3 said:
the beautiful smell of diesel burning in cold winter mornings

Oh dear... No hope

Blackburn · Aug 28, 2020

I would suspect a blown head gasket between two cylinders do a compression test to check.

romanrob · Aug 29, 2020

Don't just replace stuff for no reason...it's a waste of money and may make it harder to diagnose.

I also think compression check. It sounds to me that no 2 cylinder is doing most of the work. Is air-side ok? Maybe get some Laser lights and check that all plugs are getting a spark. Are points gapped ok?

Extreedoc · Aug 29, 2020

romanrob said:
Don't just replace stuff for no reason...it's a waste of money and may make it harder to diagnose.

I also think compression check. It sounds to me that no 2 cylinder is doing most of the work. Is air-side ok? Maybe get some Laser lights and check that all plugs are getting a spark. Are points gapped ok?

Quite right, diagnose first and replace only that which needs to be replaced.
A compression check is what I'd do first as well, make sure of the basic soundness of the engine otherwise all your efforts with ignition and carb might be wasted. You can buy a compression tester kit on Amazon for very little money; cheaper than a garage would charge you to do the job.

85Santana3 · Aug 29, 2020

I am not sure if by blown head gasket you means just the gasket or the head of engine. The gasket alone is not expensive and easy to change, top of engine once I had to change and is quite expensive. Which one do you mean?
I watched a few youtube videos and did a test one suggested (opening radiator cap and letting engine get hot, then closing the radiator cap and watching the reservoir) It passed that one. I will do compression and other tests to be sure this week. I have a feeling my carb is the culprit (hopefully)

kermit_rr · Aug 29, 2020

85Santana3 said:
I am not sure if by blown head gasket you means just the gasket or the head of engine. The gasket alone is not expensive and easy to change, top of engine once I had to change and is quite expensive. Which one do you mean?
I watched a few youtube videos and did a test one suggested (opening radiator cap and letting engine get hot, then closing the radiator cap and watching the reservoir) It passed that one. I will do compression and other tests to be sure this week. I have a feeling my carb is the culprit (hopefully)

Blown head gasket means just the gasket needs replacing. The actual head is quite reliable and long living but still check the gasket face for flatness and make sure it's clean

Colthebrummie · Aug 29, 2020

When you say the spark plugs are black, are they dry and black or oily and black. Black plugs usually means the engine is running to rich, this is usually caused by a badly set up carb or a blocked air filter. Try disconnecting the air filter to see if the engine runs better. The air mixture screw is near the base of the carb. Turn it all the way in, don't over tighten, then back out again about two and half turns. You might need to adjust the throttle setting after doing this. I doubt if it is anything electrical but it never hurts to replace the plugs, leads, dizzy cap, points and condenser. I also don't think it is your head gasket, that would be the last thing I would check. The compression figures on my 1977 series three are all over the place but it ticks over nicely and will get up to 60 mph easily.

Col

Birdbrain · Aug 29, 2020

85Santana3 said:
carb is zenith 36 and was rebuilt a year ago although since then it never ran properly! all other stuff are a year and half to two years old (spark plugs, leads, cap, ...). I will change everything to see what difference it will makes. It is cheaper than letting the mechanics do it.

Dan could you pls explain a bit. (or maybe a link to an article or video) thanks.

I had a 2004 Jetta diesel, you just reminded me of the beautiful smell of diesel burning in cold winter mornings

Your first sentence perhaps provides a clue? Not run properly since carb rebuilt last year. Sounds like, as others have said, it’s running to rich. That could either be the jets or choke. Is the choke jammed open ? I’d be looking at the carb....

kermit_rr · Aug 29, 2020

Birdbrain said:
Your first sentence perhaps provides a clue? Not run properly since carb rebuilt last year. Sounds like, as others have said, it’s running to rich. That could either be the jets or choke. Is the choke jammed open ? I’d be looking at the carb....

Something itching the back of my brain that there's one carb where it's easy to get the choke cable the wrong way around? On when you think it's off?

Turboman · Aug 29, 2020

Blackburn said:
I would suspect a blown head gasket between two cylinders do a compression test to check.

Me too. And if it has been driven like that, it may have cracked the head.
Seen this before, and always with one of the totally useless copper head gaskets.
With composite gasket, you never get this problem.

Series 3 which lead to which spark plug?

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