In mid October, I attempted a test start on my 1919 Speedster. 6v, battery, generator with original cut-out, distributor, no mag, no starter. Had several starts, but it wouldn't stay running due to carb issues.
Today, I got the carb on and tried it again. this time, I have no spark. Battery's good, checked and got 6v across the coil terminals. Pulled #1 plug and laid it on the head; no spark. Pulled the dizzy cap; no spark across the points. Ignition wiring hasn't changed or even been touched really since October. I have power to my lights and fuel pump also. Ideas? Thanks.
Bad coil. Bad condenser. 2 possibilities. "No spark across the points". Were they open when you checked for juice at the moveable point arm? If closed it's going to ground.
Make sure you're getting current flow through the points. They can get dirty or corroded. Some really fine (Say....400-800) sandpaper folded in half and drawn between the points a couple of times will clean them up. Also, a helpful technique when troubleshooting a system such as this.....with the distributor cap removed, disconnect the coil wire from the cap and place it somewhere that will give you a small gap (1/8-1/4 inch) between its end and a ground. You can then break the points by hand to check if your repairs have fixed the problem. The coil wire should spark to ground every time you open the points.
Thanks guys. Charlie - I checked for spark at the points as I cranked the engine over with ignition on. No spark when they opened on any lobe. Would a coil or condenser that worked fine in October go bad? I guess they could...
Hal - points are clean, as they were in October, but I'll check to be sure. Thanks for the coil wire tip.
Dave I'm not sure we're on the same page with this spark at the points business. If all was working you might not actually see sparking at the points as they open and close. Got a test lamp? Make sure the points are open. Turn the ignition on and check through the system from the + terminal on the coil, the - terminal on the coil, the point electrical connection on the dist. and the moveable point arm itself. Let us know the results. The lamp should be lit at all the terminals mentioned. We'll go on from there.
Just checking resistance on coil wires (all okay - zero ohms), and also got zero ohms when measuring between the open points. That doesn't seems right, does it? Should be an open circuit when the points are open. What would cause that to be the case? Checked with ignition off.
First thing I'd do is put a test light between the coil B+ and ground (key on), if it lights up put the light to the other side of the coil or at the wire down at the distributor, Crank engine, the light should turn on and off.....You can take it from there. When the points are closed the light goes off, when the points open the light comes on.
So if the light doesn't flash, if it stays on or just off you'll know where to look.
Dave, forget the ohms business right now. Keep it simple. Use either Mike's or my suggestions with a test lamp. Systematicly check it out.
There should never be spark at the points. If you see a spark there something's wrong.
With the points open you should measure battery voltage on one side and no voltage on the other side.
Full battery voltage to the points, such as in starting will cause arcing at the points. You don't want it to continue during running which is what a resistor and a correct condenser help to do. Arcing causes the volcano and pit condition you sometimes see as the arcing causes metal transfer from one contact to the other. I believe DC current is the reason for the one way transfer and I'm pretty sure the mag's AC is why T coil points can last so long.
I'll have to rig a test light tomorrow and check all the connections as you describe. Thanks again, and I'll keep you posted.
Check the pin that holds the brush in the commutator.
Thas a joke, I say thas a joke son. I hope.
You didn't mention the brand of distributor on your speedster..
If it's similar to a original Model A distributor, there may be a broken ground wire under the advance plate to the distributor housing.
It's a "period correct" Delco. Here's a photo.
What is the point gap measuring ? Bad memory recalls .018 to .022 " . Those condensers are difficult to find in good condition. Careful with the brittle housing ..... don't ask me how I know.
Charlie, didn't mean to walk over your post.
Dave, the kiss method is the best way and keep dividing your problem.
I'm with Charlie here, the test light will indicate not just voltage but an ability to draw current. Reading voltage alone can give a false/positive conclusion.
Of course analog is the way to go with T's but with my digital meter I can touch the B+ lead, touch you, have you hold one of the meters leads with the other to B- and the meter will read close to battery voltage..!
A quick check would be with the spark plug on the head and the center coil wire out of the distributor cap and about 20 thousandths from the block or a good ground turn the engine over with the key on. You should se a spark from the wire every time the points open. If you get a spark, then you can see whether each individual plug is getting a spark.
Is very possible for things to change between October and December. The weather gets colder and wires can contract which could open a connection especially if the connection was loose to begin with. Check all your connections between the coil and distributor and between the ignition switch and the coil, including the switch itself.
Just for fun, polish the points as Hal suggests. You say they're as clean as in Sept., however, there can be a thin film of oxide that really isn't easy to see but will kill your ignition. It's happened to me several times.
Ok, here's an update:
1. Points are clean and polished, gapped at 0.015". All lamp tests done with points open and ignition on.
2. All battery, wire, switch, coil, distributor, spark plug connections are clean and tight.
3. Test lamp lit on coil terminals.
3. Test lamp is not lit on distributor terminal and movable point arm.
4. Did the spark plug on head/coil wire pulled from center of dizzy close to ground; no spark when I crank the engine.
Can it be that the coil simply isn't sending out power to the distributor? Just seems strange that the same wiring and parts that worked a few weeks ago don't work now.
FWIW, Here's a pic of the coil as mounted and wired.
I tried adjusting the point gap to 0.20" and re-tested the spark plug on the head with the coil wire close to ground. Still no spark at all.
Points open - ign. on
(#'s from your posting)
#2 lamp lit on coil terminals
#3 lamp not lit on dist terminal or moveable point arm.
Din't you just lose power in the wire going from the coil to the points? (you shouldn't have)
Charlie - I may be testing incorrectly. I have power across the two wired coil terminals. Should I test each one individually? What connections? Thanks for your help, and patience.
Check your internal wiring for breaks. A coil wire can look good from the outside but can be broken inside. Test each wire for uninterupted current.
Points open ignition on: you should have a lit lamp at both coil terminals (the one's with the wire and nuts on them) and at the terminal on the distributor body and on the moveable point arm itself.
I'm looking at your photo. Where does that white wire on the coil go to? In any case it shouldn't be there especially if it's a ground. In fact I don't know what I'm looking at with those sideways plugs.
That's how I tested, if I understand you correctly. Connecting my light leads to each terminal on the coil, the lite is on. I get no light when checking the distributor terminal and the point arm. Testing the coil wires shows zero ohms, so the wires themselves are good. Doesn't seem like I'm getting any power out of the coil to the distributor, just across the two coil terminals.
Photo of white wire and black wire coming from one of the terminals on the coil is confusing to me. That black wire looks like a high tension spark plug wire, and that jus' don' seem right to me.
Charlie B - I think those "sideways plugs" indicate a Rajo or "Fronty" or some other type of overhead valve accessory cylinder head.
Not sure why I even comment on this type thread as 'lectricity really ain't my "thing"! But the wires on that coil really don't look right,.......harold
OK once more with feeling: You have a yellow wire going to one coil terminal. I'm assuming that's + or battery power. Connect one test light lead to ground and touch the other lead to the terminal with the yellow wire on it. Points open ign on. The lamp should light. Move from that terminal to the terminal with the black wire on it and put your test lamp lead on it. The lamp should light. Move to the terminal on the distributor body. The lamp should light and if you touch the moveable point arm the lamp should light. Again: what is that white wire on the coil terminal for?
Try this. Hope it clear enough.
Dave follow Charlies instructions. The lite lights up on the key side of coil...Check. No problem from the the key to coil.
Move to the other side of the coil. Points open lite lights up....check
Turn the engine over until the points close, light goes off check...
Light stays on....oops. Open points.
If while turning the engine over the lite stays off always, check out the movable insulated point. Insulator missing?
This is why I asked that you turn the engine over with the light hooked up. It MUST go on/off/on/off.
When the points close the current saturates the coil. The current will travel thru to ground (points).
When they open the field collapses and induces high voltage in the coil to fire the plugs (the short explanation). If the points do not provide a path to ground you will not fire. Divide the problem up. The condenser is not an issue at this point in trouble shooting. The moveable point is insulated, the fixed point is tied to ground. Take your on/off light reading at the both the coil and the distributor. This will verify the integrity of the wire from the coil to the dist.
Last note, if you cannot get a light on the dist side ever, turn the key on and hook a wire to the dist side (for giggles disconnect the existing wire)and touch the other side to the head. See a blue spark.....Head to the points. No blue spark, the coil is suspect.
Remember the lite lights up when the points are open because it is the path to ground. If the points never see a ground the lite stays on. If the points are grounded the lite stays off. BTW you can save time with the points closed and use a piece of paper to simulate open points by inserting the paper between the points
Man now I'm confused.
Ok, I got it. Don't remember doing it, but I must've pulled the white ground wire off and replaced it in the wrong place. Moved it off the terminal (to the coil bracket for grounding) and re-tested. All worked, including the spark plug on the head test. Had to be something simple, but I just wasn't seeing it. Thanks to all who chimed in, and especially thanks to Charlie and Harold. Yes, it is a RAJO head, and with all of your folks help, soon it will roar to life again. Much appreciated.
Sounds good but you really do not need a ground to the coil bracket. Just completely remove that wire and it will work fine and look like you know what your are doing.
What Jim said.
Ok, will do. Wonder why it was there to begin with if not needed...