Engine first start

[Mertz]

I read the 2020 articles about testing the coil and understand what was said. It however conflicts with other coil testing procedures I’ve read. From this forum it says there should be no resistance, 0 ohms readings, on a good coil from the positive to negative terminals and from either terminal to the high tension distributor wire. Also the high tension wire should have no resistance. Others testing procedures say the higher resistance the better the coil. I have 2 old firewall coils, one came with the truck and one used one off eBay. I assume the original coil used to run the truck many years ago. 
 

The readings for the eBay coil are:  +to high tension 36, +to- O, -to high 36. The original coil was + to high 3.2. Coil is in the car so I couldn’t test the negative side. High tension wire and + wire to the distributor both read 0 ohms. 
 

I tried using the suggestions in the 2020 article but could not get a consistent hot spark on the plug. I installed a plug on the high tension wire from the coil and grounded it on the - terminal of the battery. I put a jumper on the positive battery terminal and touched it to the + terminal on the coil. Got very little spark. 
 

Is there a wrong way to wire the switch?  I believe I put it back on the way it came off. If it is just a switch it shouldn’t matter should it?

[Mertz]

That should read + terminal of the battery not -  

[Mertz]

That should read + terminal of the battery not -.  To be clear the multimeter was set at 200k for these readings. So maybe this means 36k not 36 and 3.2k not 3.2. I’m so confused. I think I’ll start over from the beginning. 

Edited July 14, 2023 by Mertz

[maok]

There should be anywhere between 1 to 2ohm resistance or 3 to 4ohm resistance across the primary ie + and - terminals, depending on which type of coil you have. For this reading, make sure your multimeter is set to the lowest reading ie 200ohm setting.

[Ivan_B]

34 minutes ago, Mertz said:

I think I’ll start over from the beginning. 

Probably a good idea. So, you've god a new car (or finally got around to working on an old one) and are trying to start it up? When all the parts are installed on the car, you have no\weak spark while the engine is cranking? If both coils produce the same results, it is possible that they are both bad, but the problem could be something else too.

[Mertz]

I started over and followed the directions carefully. The original coil, tested in the truck, got an occasional weak spark but a good jolt to my hand trying to ground it. I tested my replacement coil and got an occasional good spark also a good jolt to the hand. I will hook up the replacement coil on the truck and do another test. 
 

I checked the ohms again on the replacement. Almost 0 between + and - but off the chart between both + and - and high tension terminal. 
 

I think I’m going to borrow the coil from my studebaker and see if I can get spark and the timing set up. 

[DJ194950]

Check your volts to the coil while cranking and also the grounds to the coil and distributor.

 

DJ

[Merle Coggins]

13 hours ago, Mertz said:

I checked the ohms again on the replacement. Almost 0 between + and - but off the chart between both + and - and high tension terminal. 

 

There should not be any continuity between the coil output lead (high tension terminal) and the + or - terminals. You should get a little over 1 Ohm between the + and -. To check the secondary winding check from the output terminal to the coil case. 

[Sniper]

13 hours ago, Merle Coggins said:

There should not be any continuity between the coil output lead (high tension terminal) and the + or - terminals.

 

There most definitely is continuity between the coil output and the + and - terminals.  They share the ground connection internal to the coil.

 

http://www.mgaguru.com/mgtech/ignition/ig108.htm

 

On 7/15/2023 at 5:09 PM, Mertz said:

I checked the ohms again on the replacement. Almost 0 between + and - but off the chart between both + and - and high tension terminal. 

 

Try changing the ohms range to 20k or so

Edited July 17, 2023 by Sniper

[Mertz]

I just checked the studebaker coil in the car with no battery. I got 1.6ohms between + and - on the lowest setting and 14.6 at each side + and- to the high tension wire with the meter set at 20k. I know this coil is good because it has run my studebaker for years. I think I’m going to install my replacement coil because it seems to have the best readings and see what happens. 
 

Maybe a dumb question but since these are positive ground do I need to buy a + ground coil or are the windings the same for primary and secondary and interchangeable?

[Sniper]

I've seen coils labeled 6 volt POS so I'm going to assume it does make a difference and that you should wire the positive terminal to the points

 

Although I will admit the coil in my Cambridge was wired backwards when I bought it and it ran.

Edited July 17, 2023 by Sniper

[Mertz]

I installed the 49 studebaker coil.  I set the engine to TDC and rotated the dizzy with a grounded plug on the number one wire and got no spark. After taking a closer look I found that the distributor that came with the engine did not open the points when rotated to fire number one. I tried multiple adjustments and could not get the plug to fire. I installed the distributor off the original engine that I had cleaned but had not replaced the points or condenser. When I did it was one wire off, firing  number 4 instead of one. I rotated the wires and got number one to fire at TDC. I squirted in some starter fluid and it fired off for a few seconds. Time for new points and condenser. BTW there wasn’t enough gas in the tank to fill the fuel pump or the carb. FIRST FIRING IN PROBABLY 40 YEARS 

[Los_Control]

Sounds kinda normal sorry to say.

Good thing is the engine has been worked on over the years.

The oil pump when installed it is critical to put the engine on TDC first. Then when the distributor is installed it will also be TDC since the distributor is run off of the oil pump.

 

Sadly it is a step that many mechanics have overlooked over the years .... drop in the oil pump then figure out the distributor location later.

 

I'm only suggesting it is a common issue for the distributor wire of #1 to be installed in the 7 0'clock position of the distributor cap is wrong. .... Should be correct though.

 

My truck they tried to get it right, installed the oil pump 1 tooth off .... My #1 plug is at 6 0'clock instead of 7 0'clock as manual suggest.

 

I had to figure this out myself for my first start & correct plug wires as needed ..... Many others also ..... there is a reason why some suggest to put it up on TDC then check things out.

[Mertz]

I changed out the points from the first distributor that looked like new and now I don’t get spark. I ordered some new ones from NAPA. I think that in the long run Pertronix is the way to go.

[DJ194950]

Boy,  the Pertronix statement will get the hornets out of their nests..

 

DucK! Run!  ?

 

DJ

[Mertz]

I installed new points and condenser and tried to start the engine after checking for spark at #1 TDC. I got spark but the engine wouldn’t start. When I got backfire I knew I was 180 out so I rotated the dizzy and it fired right up. It didn’t run long because it only had the gas I poured into the carb. After a few starts I noticed oil leaking out of the filter canister. I had not tightened it waiting for a filter but thought it would not fill because of the intermittent nature of the system. It was full.  I guess the oil pump is working. First start in probably 40 years. It sounded good with no muffler and 4’ of straight pipe. 

[Mertz]

I have the truck starting up and running well with a very few cranks. A minor timing reset made the difference. I decided to try using the 2 firewall coils I have. The one I bought from eBay worked. That was the one I thought was the better coil. So I installed the original coil and it seems to work just as well.  The Studebaker coil is back on the Studebaker.