Running Rough: Dizzy questions (pics)

[NC Rover]

So I cranked up the rover the other day and it was running rough with some black smoke coming from the exhaust. It never does this. Smelled like it was running rich. So I took the dizzy cap off and it looks as if it is misfiring. (Note: I am running a Petronix igniter...no points).

I also checked the plugs and they smelled like gas.

Obviously it is running rich.

Questions:

1.) Could I slightly rotate the dizzy forward/backward to prevent this or is this something regarding the carb? I've been running the same carb and dizzy for over a year now with no problems until recently.

2.) In which direction does the arm on top of the dizzy rotate...clockwise or counter-clockwise?

Sorry for the stupid questions.

http://i32.photobucket.com/albums/d49/W8kbrder/Land%20Rover/dizzy1.jpg

http://i32.photobucket.com/albums/d49/W8kbrder/Land%20Rover/dizzy2.jpg

http://i32.photobucket.com/albums/d49/W8kbrder/Land%20Rover/dizzy4.jpg

[Apis Mellifera]

First, it's time for a new distributor cap and rotor. The cap has a carbon build up, which can cause arching which can lead to a misfire. A misfire can cause unburned fuel to collect on the plugs. Arching can also produce a weak spark, leading to poor combustion. To put it in the simplest terms, the electricity leaves the coil, goes int the center of the dist. cap, the rotor routes the electricity to the right spark plug at the right time. If something prevents some or all of the electricity from making it to the spark plugs, you can get the symptoms you describe.

The rotor spins counter clockwise.

Rotating the whole distributor will change the timing. An out of time engine will also produce poor running, loss of power, but generally you can't get keep it running and also get it far enough out of time to blow black smoke and get raw gas on the plugs. A stuck choke certainly will do that.

[I Leak Oil]

I second the new cap and rotor but this sounds like a fuel problem to me. Which carb. do you have? Zenith?

[NC Rover]

I second the new cap and rotor but this sounds like a fuel problem to me. Which carb. do you have? Zenith?

I will swap these out.

I have a Weber DTML double-barral.

[Apis Mellifera]

A Weber certainly can be a temperamental carb, but I'd expect the plugs to be sooty if the carb was causing the problem. Plus, the onset was sudden. Generally, you'd have a chronic problem if the carb was over fueling. Raw gas on the plugs means they aren't firing or aren't firing well. I'd still focus on ignition.

[NC Rover]

A Weber certainly can be a temperamental carb, but I'd expect the plugs to be sooty if the carb was causing the problem. Plus, the onset was sudden. Generally, you'd have a chronic problem if the carb was over fueling. Raw gas on the plugs means they aren't firing or aren't firing well. I'd still focus on ignition.

Here are some pics of what the plugs smell like. Now that I think about it, the exhaust has been smelling a bit rich lately...but I've never had any running issues. It happened after a cold start one day. Just instantly started running bad. I'm definitely going to replace the cap and rotor as well as the plugs to be on the safe side. However I guess I'm trying to find out what caused this in the first place: Carb or Dizzy or both combined.

http://i32.photobucket.com/albums/d49/W8kbrder/Land%20Rover/dizzy5.jpg

http://i32.photobucket.com/albums/d49/W8kbrder/Land%20Rover/Dizzy6.jpg

[NC Rover]

The cap has a carbon build up, which can cause arching which can lead to a misfire.

Rotating the whole distributor will change the timing. An out of time engine will also produce poor running, loss of power, but generally you can't get keep it running and also get it far enough out of time to blow black smoke and get raw gas on the plugs. A stuck choke certainly will do that.

I checked the choke...definitely not stuck.

The whiteish haze on the inside of the cap was the part of the cap that rests against the magnet.

I never had any loss of power or smoke from the exhaust leading up to this. As soon as I cold started it, I noticed it running rough with a bit of black smoke....not a lot but you could tell it was coming out.

[jac04]

From the looks of those plugs, you have been running rich and/or have weak ignition.
Google "reading spark plugs" for a wealth on info on what the plugs can tell you.

http://www.aa1car.com/library/sprkplg2.htm

[NC Rover]

From the looks of those plugs, you have been running rich and/or have weak ignition.

I know the Jacobs Ignition and Super Coil are working fine. The Petronix ignitor is new as well. Plug wires are brand new.

I'm guessing there is something small that is causing this rich mixure. Maybe carb needs to be adjusted? Dizzy adjusted?

I'm going to replace the plugs, cap and rotor. Hopefully I can solve the problem.

Thanks again to all the suggestions/information.

[Nium]

The carb shouldn't be adjusted till the ignition system is solid. Since your cap is burned definitely do not adjust the carb till the new cap, rotor, and plugs are in. Looking at your pictures of your distributor cap my 2 cents would be that the cap is the cause of your issues and as others have said electric issues happen all of a sudden.

http://farm5.static.flickr.com/4095/4753615668_19e03f71a5.jpg

The areas of the cap I circled in red have been burned away. Compare it to your new cap when you get it and you'll see what I mean. Once you get the new ignition components reset your ignition timing as it's probably off.

Has anyone else seen a cap burn like this? It's a first to me.

Cheers!

[bkreutz]

That looks like the timing is a bit too advanced, normally the spark would jump when the rotor is aligned with the center of the post. (this is assuming my mind is visualizing the rotation with the cap orientation correctly:confused:) so it could be too far retarded if I'm wrong. (CCW rotation should look like CW rotation when viewed from an inverted view). (I think). Anyway I think you get the idea where my thinking is going. It also looks like there's more spark voltage than that cap is designed to handle. Are you using a Pertronix high output coil? Could be it's too much for the stock cap to handle. Just a couple of thoughts. HTH

[cgalpin]

If the rotor spins counter clockwise, don't those burn marks indicate that the timing was too advanced and the spark was firing early?

[stomper]

My cap looked very similar to this when I replaced it about 4 weeks ago. I am running a stock coil, but have an MSD ignition system installed by the previous owner. (It still has points, it just boostes the ignition current I believe) Since I time mine by ear, I assumed it was because I was running too far advanced, but it likes the timing I have it set at, and runs very smooth.

I'm anxious to hear how you get on with this after replacing the cap, rotor and plugs.

[kevkon]

Your problem may, as often happens, be a combination of things. Reading your description of the aftermarket ignition system you have and the condition of that dist. cap, would make me wonder if you have a compatibility issue. What is the resistance of the Super Coil you are using?

[NC Rover]

If the rotor spins counter clockwise, don't those burn marks indicate that the timing was too advanced and the spark was firing early?

I believe you are right. If the arm is spinning counter-clockwise, then those burn marks are occurring right before the arm gets to the metal contact point.

So that would mean I need to rotate the dizzy clockwise just a hair. Does this sound correct?

[NC Rover]

It also looks like there's more spark voltage than that cap is designed to handle. Are you using a Pertronix high output coil? Could be it's too much for the stock cap to handle. Just a couple of thoughts. HTH

This could be a possibility as well. I currently have a Jacobs Ignition with a Super Coil and Petronix Ignitor (no points).

However I've run this setup for about 3 years now with no problems.

If there was in fact too much voltage for the cap to handle, what would you recommend I do to balance it out? Are there aftermarket heavy duty caps made specifically for that kind of voltage?

[NC Rover]

Your problem may, as often happens, be a combination of things. Reading your description of the aftermarket ignition system you have and the condition of that dist. cap, would make me wonder if you have a compatibility issue. What is the resistance of the Super Coil you are using?

Thats a good question as it was installed by the previous owner who probably had the same setup for several years before I bought it off of him.

My engine is the 2.5L w/ a Turner Engineering head (oversized valves/higher lift cam, etc). Not sure if this would have anything to do with the choice of Ignition setup.

Both the Weber DTML 34/36 Carb and Lucas Dizzy are about 5 months old so they are pretty much new.

How can you determine how much voltage is coming from that Super Coil?

[kevkon]

It's not the voltage, it's the resistance and amps that are an issue with the Pertronix Ignitor ( which I assumed is what you have). Go to their site http://www.pertronix.com/support/default.aspx if you don't have a manual. You can measure the resitance of your coil or look up it's specs.

[bkreutz]

There's probably a machine to test coil output, but that's kinda out of the realm of owners, only option would be to ask the original manufacturers. I don't think there are HD caps made for a Rover (not enough of a market I suspect) But all the high power coil/ignition manufacturers make a HD cap for the normal hot rod stuff (Ford, Chevy, Dodge).

[cgalpin]

I believe you are right. If the arm is spinning counter-clockwise, then those burn marks are occurring right before the arm gets to the metal contact point.

So that would mean I need to rotate the dizzy clockwise just a hair. Does this sound correct?
Yes, but make marks to keep track of what it was before messing with it. I haven't adjusted the timing on a series yet so can't offer any other advice.

[Apis Mellifera]

stomper: MSD stands for multiple spark discharge. It doesn't increase the spark amperage, it just sparks rapid fire rather than a single discharge. It makes for a more complete burn.

In my MGA, I ran a Lucas Sports coil, an MSD 6AL, and stock points when I was racing it. It ran well, but the points did not last as long. I think your components are fine. You must just have a lot of hours on that cap.

The rotor just brushes the terminals in the cap. This produces some arching and resistance. Over time, the arching creates the deposits you are seeing. The deposits create more resistance, which creates more arching, which creates more deposits... The reduction in performance is gradual and isn't noticed until a misfire develops. The misfire causes the plugs to foul and it's a downward spiral from there.

Your plugs look sooty to me rather than wet with gas. That suggests a weak spark and/or a carb running rich.

I think the biggest mistake people make with British machinery (and what rarely produces satisfactory results) is to attempt to tune around faulty parts. I've been fooling with these things for over a quarter century. I've been hearing how unreliable British cars are, how poor the electronics are, and how difficult they are to keep running. To me that says more about the mechanic than the machine.

Bit of a tangent there and I'm not suggesting that applies to you, NC. My point is ALWAYS replace worn or faulty components FIRST. THEN you make tuning adjustments. In this case, I'd replace the plugs, rotor, cap, and probably the wires too. Next, I'd check/adjust the timing. Finally, I'd check/adjust the carb.

If it ran well before and then didn't, the timing and carb didn't just unadjust themselves.

Good luck.

[kevkon]

I agree Apis, you are dead on.
NC Rover, the arcing is not remedied by turning the distributor. As Apis said it's common and sometimes exaggerated by ionization in the cap or a faulty ignition component. Occasionally we would see this as a result of too much spark plug electrode gap in higher compression motors. In a sense the current seeks the path of least resistance.