Electrical woes

[Gufshoz]

I’m having difficulty getting my engine to fire, so I’m working my way down the Les Andrews trouble shooting guide. My coil checks out at 1.5 ohms from + side to - side. When I test the high tension wire to either of the small posts I get a reading of 12.16k ohms. Les’s book says it should read 6.7k to 10k ohms. Could my higher resistance be causing an issue?

[Patrick L.]

Are you getting spark at the plugs ?
Are you getting spark from the secondary ignition wire ?
Are you getting battery voltage [ 6v] to the open point arm ?
Are you getting 0 volts to the point arm when its closed ?

I doubt the coil is your issue. Coils can go bad, especially an oil filled one, but, its kinda rare.

[Jim/GA]

Originally Posted by Gufshoz

I’m having difficulty getting my engine to fire, so I’m working my way down the Les Andrews trouble shooting guide. My coil checks out at 1.5 ohms from + side to - side. When I test the high tension wire to either of the small posts I get a reading of 12.16k ohms. Les’s book says it should read 6.7k to 10k ohms. Could my higher resistance be causing an issue?

No. If it had infinite ohms or zero ohms resistance, that would be a bad coil.

See my recent reply to "No Voltage on Ignition 1929 Phaeton". Get a test light like that. Trace your power through the wires using the wiring diagram as your roadmap.

When did the engine last run and what have you done to it since then?

[Gufshoz]

Thank you gentlemen. As my brother preaches to me, “electricity is like water...just follow it down hill.” I traced it all from the start and now I think that part is ok.
Patrick, you asked what I’ve done since she ran right. It all started with a blown head gasket. From there:
Head resurfaced
New timing gear
Replaced old valve with modern and ground them in
New manifolds (because the old ones were in poor shape and had the heater fins)
Changed valve cover to one with oil filter
She runs now, but rough. The timing is dead on, so I’m questioning that I may have one of the new valves hanging up. I can kind of hear a light grating in #4 and that’s where she stumbles. How can I tell? Compression is 60lbs in all cylinders.

[Patrick L.]

Its hard to tell here. What does 'ground them in' mean ? How did you cut the valve seats and set the face contact in the middle of the face ? How wide are the seats ? How well did the valves set in the guides ? Did you check the manifold alignment ? Does it run rough at idle, higher speed, or, all the time ? Is #4 the only cylinder you worked on ?

[chrs1961815]

Sponsored Links (Register now to hide all advertisements)

Grinding valves to fit them is not a good way to do it. You are better off cutting the seats at angles with special tools - for sure they will seal if you do this. Most seats just need a little clean up unless they are badly pitted.

[Gufshoz]

Sorry, Patrick. I should have said lapping them with compound and a dowel with suction cup tool. Several hours of hand rotating and then checking with Prussian blue. I used a medium grit lapping compound to start and finished with a fine compound. I went from 45-50lbs to 60 lbs of compression, so I' happy with the valves seating.
I used a straight edge to check the surface of the block for the manifolds. The first time I had too much pull from an improperly fitted muffler. Now the muffler is off and I feel that the manifolds are fitting well.
I admit that I'm not a mechanic. I had some basic knowledge, but most of what I'm doing comes from info here on this site, through Les Andrew's books and from the internet/YouTube. Other than Les's books, I sift through everything to try to get the information I need. Engines intimidate me, so if I can't simply fix this, my next step is off to an engine rebuilder. This car was a daily driver for years until I blew that gasket.

[Jim/GA]

Did you use "gland rings" in the exhaust manifold when you installed it? They can prevent the intake manifold from seating and sealing properly.

[Gufshoz]

I did use gland rings, but I checked the fit first, without the gaskets. I finally got her to start...just. Saturday she started and ran, but not well. Yesterday I could barely get her to start and had to fiddle with the GAV and spark advance in order to coax her to stay going. I feel like a surgeon whose patient can't tell him where it hurts.

[jm29henry]

Great analogy more like a veterinarian than a doctor !!!
Best of luck to you I will keep checking on your status there is good learning here for all

[katy]

Originally Posted by Gufshoz

I’m having difficulty getting my engine to fire, so I’m working my way down the Les Andrews trouble shooting guide. My coil checks out at 1.5 ohms from + side to - side. When I test the high tension wire to either of the small posts I get a reading of 12.16k ohms. Les’s book says it should read 6.7k to 10k ohms. Could my higher resistance be causing an issue?

Try a different coil.

[Gufshoz]

HOORAY. She's running, on borrowed parts. Thanks to my fellow club member, Jim, who brought boxes of ignition parts. Here's what we did: reversed polarity on coil and used an original distributor. My wire from the switch to the lower plate was soldered in place and we didn't think it was getting a good contact so we switched to his lower body of the distributor and my cap and modern wires. It took lots of trial and error, and that's how you learn.
Also, Jim made an awesome coil and condenser demonstration model to check both. I ended up throwing away a couple of condensers.

[Gufshoz]

HOORAY. She’s running with help from Jim, one our club members and his boxes of extra parts. We worked over the afternoon through trial and error until we figured out it it was reversed polarity of the coil and a weak solder joint on the lower distributer plate. Thanks to Jim’s spare parts I think we know what I need to replace/repair. And thanks to all of the advice from this site.

[Patrick L.]

Coil polarity should be the same as the battery polarity.
But, the engine will still run if its reversed.

[old31]

Guf just as an fyi, Patrick is correct in his statement about polarity.

So, it was one of the other fixes that repaired it.

You are correct, that is how you learn, and that is now what makes you an expert on that type of repair. Nice job.

[rotorwrench]

I always test the polarity of a coil. You just can't trust manufacturers these days. I would even test an old original just to make sure. The Nu-Rex tool makes it easy but a lead pencil will work.
https://www.nurex.com/sparklite