Sick 59 Lark 6

[Guest]

Gang, I was at J-sin's place this morning, trying to diagnose why his Lark wouldn't start. Cranks fine, he's put in new points, rotor, capacitor, cap and coil. It all looks good but there's no spark at the plugs. He did everything with the dist. in the engine and my dwell meter showed maybe 45 degrees, which, though too much, shouldn't have kept the car from starting. I'm thinkin' there's a short or bad ground in the dist., and suggested he pull it and give things an up-close look and re-gap the points .020 at the kitchen table. He's a tad reticent to pull the dist. having never done it before, but knows stuff has to go back as it came out and line up.
What am I missing here..? Thanks!

Western Washington, USA

[gordr]

Well, either the coil isn't getting grounded through the points, or it's getting grounded ALL the time. The points have to "make and break" the ground path for the coil primary winding. If they can't "make" because of a bad wire, or coating of wax on the point surfaces (not unknown on new points), there will be no spark. If they can't "break" because of a short to ground somewhere, there will be no spark.

And, of course, if the coil isn't getting 9-12 volts at its (+) stud, there's going to be no spark.

Your best diagnostic tool is a 12 volt test lamp, the kind that looks like an ice-pick with an illuminated handle. Connect the clip lead to ground, and check for voltage at the (+) stud, ignition on. The lamp should come on brightly, and if you hit the starter, it should get a little brighter, indicating the resistor bypass in the solenoid is working. A little flicker while cranking is perfectly normal.

If the lamp does not light at all, or ONLY lights while cranking, you have a problem with the ignition switch, resistor (wire), or interconnecting harness. If it was merely a resistor problem, the car should fire when being cranked, but immediately die when the key is released. I don't think that's the case here.

Now move the test lamp probe to the coil (-) terminal, keeping the clip lead grounded. With the ignition on, the lamp should be illuminated when the points are open, and go dark when the points close. While cranking, it should flash repeatedly and regularly. Either fully lit, or completely dark is normal with the ignition on, and engine stopped, because we don't know if the engine happened to come to rest with the points open or closed. If the lamp should happen to come on dimly with the engine stopped, that's a strong indication of a PARTIAL short to ground in the distributor; maybe a bad condenser, or maybe the pigtail wire is chafing somewhere.

To recap: test lamp on coil (+) should be fully lit with ignition on, may brighten somewhat while cranking. The increase in brightness may be hard to see, so don't be alarmed if you don't see it. If the lamp is lit, and STAYS LIT while cranking, you have power to the coil.
test lamp on coil (-) terminal should flash brightly and regularly as the engine is being cranked. If either constantly lit, or constantly out while cranking, you have a problem.

Do those tests, and report back, and we can go from there.

By the way, one of those test lamps should be in everybody's tool bag. Carry an el-cheapo in the car all the time, and have a good one in the workshop. If you are constantly working on six-volt cars, it would be smart to put a six-volt bulb in your test lamp to make it easier to see in daylight.

And another by the way. What's the first thing to test with your test lamp? The test lamp, of course! They get rough handling, and often the bulb comes loose in what passes for a socket. Connect the clip lead to a known good ground, and touch a KNOWN good source of 12 volts before beginning to to troubleshoot. That can save you from having a Homer Simpson moment. Doh!

Gord Richmond, within Weasel range of the Alberta Badlands

[52-fan]

Don't worry about taking the distributor out and putting it back correctly. As long as you don't crank the engine while the distributor is out it can only drop back into the right place. This is because of having an offset slot that engages the oil pump. Once I learned this years ago I always pulled the distributor on my 6 cylinder Lark to change points. It is much easier to check for frayed wires, set points, or change other parts on the workbench. Just take note of which way the rotor is pointing when you pull the distributor and put it back the same way.

1952 Champion Starlight, 1962 Daytona. Searcy,Arkansas

[jsincread]

Thanks a lot for the advice guys, I'm gonna do the tests on Wed. and I'll post again after that. We'll have her back on the road by the weekend! Thanks again for the input, [}] -Jsin

[jsincread]

O.K., Jsin here. I checked the coil with my tester and The results are pretty conclusive. With the ignition on the test light is on when the connection is on the positive post, when it cranks it stays pretty bright and flickers slightly. With the tester on the negative post with the ignition on, no light, when cranked it flickers beautifully. So where do I go from here? Thanks guys.

[Tom Bredehoft]

I once had a problem with the secondary (heavy) wire from the coil to the distributor. polish the metal ends. Also check the carbon button on the top of the rotor.

[img=left]http://www.alink.com/personal/tbredehoft/Bothcars4.jpg[/img=left]
Tom Bredehoft
'53 Commander Coupe
'55 President State Sedan
(Under Construction) 136 hrs.
'05 Legacy Ltd Wagon
All Indiana built cars

[Dick Steinkamp]

quote:Originally posted by jsincread

O.K., Jsin here. I checked the coil with my tester and The results are pretty conclusive.

Well, it means your distributor is working...at least good enough to start the car.

Are you SURE there is no spark at the plugs? Disconnect a spark plug wire, put an insulated handle screwdriver (Phillips) into the end of the wire, hold it about 1/8" away from a good ground, have someone crank the engine...look for a spark. If there is a spark there, pull the plug the wire was attached to, reconnect the wire to the plug, ground the plug, look for a spark at the electrode. If no spark, plugs are bad. If no spark in the first test, coil bad, cap bad, rotor bad, or plug wires bad.

[Guest]

Dick, when I was at Jsin's last week, I used a tool with an adjustable gap in a plastic see-thru tube connected to a plug wire and grounded. With it open maybe an eighth of an inch, there was no spark. Though the ignition wires look good, I suppose they could be bad. I examined the cap and rotor and they're both clean. He installed new points and capacitor and they look good, too. Gotta be the ign wires.

Western Washington, USA

[Anne F. Goodman]

Condenser?

Mabel 1949 Champion
1957 Silverhawk
1955 Champion 4Dr.Regal
Gus 1958 Transtar
1955 President State
Fresno,Ca

[gordr]

Ignition wires don't normally go bad all at once, nor do they fail intermittently, unless moisture is an issue. Sounds like the points are making and breaking the primary circuit OK, as the test light is behaving as it should. Yeah, a weak, or bad condenser could be the trouble. With no condenser, you will get a spark, but it's very weak. The function of the condenser is partially to protect the points from being rapidly eroded by arcing, but the energy it absorbs by suppressing the arc goes into prolonging the spark at the plugs. A condenser is a pretty cheap part, so replacing it would not break the piggy bank. Remember that it was always standard practice to replace the condenser when doing a tune-up, even if it tested good.

If the condenser is good, I'd be looking closely at the coil HT wire, the one that runs from the coil tower to the distributor cap, the cap itself, and the rotor. I've seen rotors with an internal crack get a carbonized "wormhole" from the center button, right through the plastic to the distributor shaft. That sort of damage can be nearly impossible to see. If the HT wires are the carbon type, an ill-fitting terminal can lead to arcing between the terminal and the carbon core, which gradually burns the latter back until the gap is too great for the available voltage to jump. This all happens inside the insulation, and can be hard to see. You can test the HT wires with a multimeter set to "ohms" or R X 10K. Good resistance wires should read between 5000 and 25000 ohms, as a ballpark estimate. Good metal wires should read about zero ohms. If any wire reads more than double what another one of similar length reads, I'd say it is on its way out. If any wire reads "infinity" on the ohmmeter, it is toast. Since the car won't start at all, I'd be looking at the distributor-to-coil wire first, but if it proves bad, change out the whole set, as all the wires are (or should be) the same age.

Gord Richmond, within Weasel range of the Alberta Badlands

[leroy]

You can remove plug wires at coil and check fire coming out at coil itself, no wire, If you have fire there it is the wire. If no fire I would go to the rotor , some rotors have a carbon pickup to transfer the fire to the end of the rotor, you can check continuity through the rotor, I think you said you hadn't replaced the rotor, check the continuity of the rotor.

[jsincread]

Howdy folks, thanks for all the input. Well, after replacing the coil, plugs, dist. cap, points, and condenser, we have spark. I cranked and cranked and Gretta still wouldn't start. Get this, I poured some gas directly into the carb and after alot more cranking it started. She would start only turn over once or twice and die. After stomping on the gas once the engine started she got going. I think the choke needs adjusting, but why would the engine not be getting gas to start. Once I get it warmed up she's fine. So, good news, it starts (hard) and runs. Pretty weird after finally getting spark, fuel issues. Now I've got a whole different problem. Whada ya think?