'46 Will Not Re-Start

[Mountain Dew]

I'm a Model A guy and recently acquired a '46 Super Deluxe with a V8. A new problem is whopping my butt. It starts up cold, surprisingly quick but will not re-start after I shut it down. Earlier I had replaced the fuel pump and push rod. I'm getting fuel to the carburetor and just to ease my mind that it's not a fuel problem, I squirted a little gas in the carb.........no change at all. I'm going the route of an ignition problem. The spark appears to be weak but it's there. I've swapped out condenser and coil......... no change at all. Could there be an issue with the vacuum brake throwing the timing off?

[deuce lover]

....

[Kube]

Originally Posted by Mountain Dew

I'm a Model A guy and recently acquired a '46 Super Deluxe with a V8. A new problem is whopping my butt. It starts up cold, surprisingly quick but will not re-start after I shut it down. Earlier I had replaced the fuel pump and push rod. I'm getting fuel to the carburetor and just to ease my mind that it's not a fuel problem, I squirted a little gas in the carb.........no change at all. I'm going the route of an ignition problem. The spark appears to be weak but it's there. I've swapped out condenser and coil......... no change at all. Could there be an issue with the vacuum brake throwing the timing off?

Stock coil? If so, most likely that's the issue. Swapping it? With what? Repop coils are notoriously poop. Repop condensers are like flipping a coin. One is good, the next is not.
If it starts well once cooled back off, I'd go first to the coil.
The vacuum brake is not the issue. Period.
Simply for peace of mind and to avoid future frustration I would strongly suggest you have both the distributor rebuilt as well as the coil. A reasonable investment, one that will most definitely offer you peace of mind.

[JayChicago]

Both coil and condenser will sometimes work when cold but later fail when warm. Symptom is weak spark.

I have read that brand new condensers are often bad out of the box. Condensers are cheap and easy to swap out. Maybe obtain another condenser or two and try it.

[Mountain Dew]

I agree with you Kube. It's not a stock coil. I think I have a stock coil in my spare parts along with a distributor. I should have them both rebuilt and go from there. I heard there's a guy in Florida that's good at rebuilding coils and distributors.

[JayChicago]

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“Not a stock coil.” “Recently acquired ‘46”

Maybe someone has installed an improper coil. Coil has to be matched to the electrical system on this car. 6 volt vs. 12 volt. With ignition resistor vs. no resistor.

[Kube]

Originally Posted by Mountain Dew

I agree with you Kube. It's not a stock coil. I think I have a stock coil in my spare parts along with a distributor. I should have them both rebuilt and go from there. I heard there's a guy in Florida that's good at rebuilding coils and distributors.

George Haney is "the guy" for coils. Yep, he's in Florida.
I like Charlie Schwendler for distributors. He's in New York.

Both fine men that off great workmanship at reasonable prices.

[1942deluxe]

Question, when you swapped coils are you swapping an original style coil (bakelight , rectangular Coil) or is it using a round modern style coil? Agree with Kube's recommendation for Skip Haney and Charlie.

[Mountain Dew]

Originally Posted by JayChicago

“Not a stock coil.” “Recently acquired ‘46”

Maybe someone has installed an improper coil. Coil has to be matched to the electrical system on this car. 6 volt vs. 12 volt. With ignition resistor vs. no resistor.

I swapped out the coil that came on the car with a 6v coil from my Model A parts bin. The symptoms are the same.

I would like to have the correct coil on the car. I have one that I will see if Skip can rebuild. I'm not sure where the resister is suppose to be mounted and wired up.

FWIW.......So far I have been through 3 condensers trying to figure out this problem. None of these were "New" out of the box condensers.

[Kube]

Originally Posted by Mountain Dew

I swapped out the coil that came on the car with a 6v coil from my Model A parts bin. The symptoms are the same.

I would like to have the correct coil on the car. I have one that I will see if Skip can rebuild. I'm not sure where the resister is suppose to be mounted and wired up.

FWIW.......So far I have been through 3 condensers trying to figure out this problem. None of these were "New" out of the box condensers.

Just to allow you a little confidence that you are on the correct path... I'd tested at least 50 NOS (Ford - OEM) condensers and found just six that were good.
I prefer Hunt Magneto condensers at 30mfd.
They are a bit costly perhaps - around $32, but are perfect every time.
I've attached a photo of the correct coil and ignition resister for your '46.

[Graeme / New Zealand]

Originally Posted by Kube

Stock coil? If so, most likely that's the issue. Swapping it? With what? Repop coils are notoriously poop. Repop condensers are like flipping a coin. One is good, the next is not.
If it starts well once cooled back off, I'd go first to the coil.
The vacuum brake is not the issue. Period.
Simply for peace of mind and to avoid future frustration I would strongly suggest you have both the distributor rebuilt as well as the coil. A reasonable investment, one that will most definitely offer you peace of mind.

Kube talks sense. I had similar issues with my 48. Had the dizzy rebuilt, ditched the tin can coil and got a stock one rebuilt by Skip and the old girl hasn't missed a beat in 7 years.

Edit : I found the stock condensors hit an miss and good ones would crap out too. I now run a Bosch GH208-C which is common to a lot 70s to 80s Nissan and also the 74 to 78 Honda Civic and Accord.

GB

[alanwoodieman]

send the dizzy and the coil to Skip Haney in Fla. Just sent a 46 coil to him and it sure makes the engine run good!!

[1942deluxe]

My 48 is wired bypassing the resistor on the panel under the dash that also has a circuit breaker. I'm using an IC7 Napa coil that has an internal resistor. If you are using a stock coil there should be a resistor either under the dash or on the coil but not both to my knowledge. It matters rather the coil has an internal resistor.

[FortyNiner]

Your symptoms are similar to my 46 before a coil rebuild by Skip. Zero issues with the rebuilt unit.

[Mountain Dew]

Originally Posted by JayChicago

“Not a stock coil.” “Recently acquired ‘46”

Maybe someone has installed an improper coil. Coil has to be matched to the electrical system on this car. 6 volt vs. 12 volt. With ignition resistor vs. no resistor.

Originally Posted by 1942deluxe

My 48 is wired bypassing the resistor on the panel under the dash that also has a circuit breaker. I'm using an IC7 Napa coil that has an internal resistor. If you are using a stock coil there should be a resistor either under the dash or on the coil but not both to my knowledge. It matters rather the coil has an internal resistor.

Interesting............The coil that was on it is an Echlin IC9 with no external resistor and is NOT labeled "No External Resistor Required" or anything of that sort. It does however say "6 volt". Do I need a resistor on an IC9 coil? In other words, is a resistor needed on a 6 volt coil when running it on a 6 volt system?

[cmbrucew]

IC9 echlin coil is listed for all 1920 - 1931 ford engines, no resister listed.


Bruce

[1942deluxe]

Mountain Dew, I can't say for sure on the IC9 coil. I see on the NAPA website they recommend the IC7 coil though. Listed I think for around $25.

[JayChicago]

Can you put an ohmmeter on the primary side of that Model A coil?

With 6 volts, total resistance thru the primary circuit should be about 1.5 ohm, to limit current to about 4 amps.

[Mountain Dew]

OKay..... I was able to get back to my '46 Ford.

A resistance check of the coils follows:

Echlin IC-9
Primary 1.4 Ohm
Secondary 6.9 K Ohm

Coil off of a Model A
Primary 1.4 Ohm
Secondary 9.5 K Ohm

These checks do not align with the diagram I got from a post here on Ford Barn but it is close to the 1.5 Ohm that JayChicago mentioned. Is it close enough? Could adding a resistor solve my problem? Would it be simpler to get a Echlin IC-7 coil?

FWIW.....I sent a coil and distributor to Skip Haney for rebuild.

[1942deluxe]

Can't answer your first question but sending the coil and distributor to Skip was a good move. He did the coil on my 42 Ford with a 59 A-B engine. He's really quick on turn around in my experience. After Skip's coil and a CharlieNY distributor I would say best starting flathead I've had in the last 49 years. I think if mine I'd wait to get the distributor and coil back and I think you'll be happy.

[JayChicago]

“Is it close enough?”

Definitely. Seems that the Echlin IC-9 is designed for 6volt, no resistor. You could use that. Or do as suggested above, wait for Skip’s coil.

Chances are the IC-7 is designed as an original equipment replacement, so will need a resistor. Skip’s coil will need a resistor too, if its an original coil.

[Mountain Dew]

I'm in no rush, I'll just wait to get my coil and distributor back from Skip. I'm going to need a resistor. Any recommendations on where I can get a "good" resistor from? I heard there's some junk out there. I guess I'll mount it on the coil like the picture Kube posted.

[1942deluxe]

Mountain Dew, did you check to see if there is a resistor next to the circuit breaker on the inside firewall? It should be located on the the driver's side inside firewall. Should be a wire coming from the voltage regulator running to it.

[Mountain Dew]

Originally Posted by 1942deluxe

Mountain Dew, did you check to see if there is a resistor next to the circuit breaker on the inside firewall? It should be located on the the driver's side inside firewall. Should be a wire coming from the voltage regulator running to it.

Thanks 42Deluxe! Yep it's there, right beside what I guess is a circuit breaker. I was looking more under the dash and not on the firewall. It looks like it is hooked up too. That might be my problem. I'm running a resister on a coil that doesn't require one.

I'm about to head out of town. I'll investigate more when I get back.

[1942deluxe]

Mountain Dew, you should be good to go when you get the coil back from Skip. If the resistor is in place and working you should be fine. When you get the coil back one terminal will be marked DIST and that wire will go from the coil to the distributor, the other terminal will be marked BATT. Hook your other wire up to that.

[Mountain Dew]

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I got the rebuilt coil and distributor back from Skip. I installed the coil and she fires off every time now! I'm not however getting the voltage reading that skips notes says I should have. On the battery side of the coil primary I'm getting 2.3 volts with the points closed. Skip says it should be around 4 volts. I'm getting 6.3 volts with the points open. I'll call and run this issue by him. I went ahead and installed the rebuilt distributor too.

Thanks to everybody for leading me in the right direction. I am slowly getting the bugs worked out of the ole girl.

[JayChicago]

Yeah, 2.3 volts is low. The resistor should drop about 3 volts. (it increases somewhat as the resistor heats up) Another couple tenths drop is to be expected thru the switch and wire connectors. But your battery voltage is 6.3, so you should see around 3.0 volts at the coil with engine stopped. I think you have some parasitic resistance. You could try to clean and tighten connections at the resistor and switch. Likely suspect is the switch itself....you can remove the working mechanism and clean the copper contacts. (not sure how easy that is to do on the '46)

Then with engine turning, the averaged measured voltage at the coil will jump up to around 4 volts, as Skip said. (with engine turning, points open 20% of the time, no current flow while points open, no voltage drop with no current, therefore full battery voltage seen 20% of the time)

[petehoovie]

Last year I had the same symptoms with the same voltage reading (2.3 volts at the coil) as Mountain Dew in my '34. The culprit turned out to be that the 87 year old resistor had changed value...

[1942deluxe]

Good news that you are back running!

[Mountain Dew]

Here' where I'm at with the low voltage at the coil...............

Voltage checks

Battery 6.3v
Switch In 6.3v
Switch Out 6.0v
Resistor In 5.2v*
Resistor Out 2.5v
Coil 2.3v

* I thought this voltage drop between the switch and the resistor was excessive so I doubled up the wire with a jumper and it was still only 5.3v at the resistor input. I also jumped the Input and output of the switch and still only had about 2.3v at the coil.

I called Skip and ran these results past him and he thinks its the resistor. I cleaned and checked the resistor, it's showing .8 ohms. I seen a post on here where a member named GM told how he fixed resistors. It seemed tedious. I found a NOS resistor on Ebay and I'll go that route.

[JayChicago]

Good troubleshooting!
I agree with you, something is not right about the voltage drop between switch out and resistor in. Should be no drop there. Is something else connected there that could be leaking some voltage to ground?
Yeah, try replacing the resistor, but I doubt that’s the problem.

Let us know what you find as you work thru this mystery.

[FlatTopFreddie]

Make sure you are getting GOOD ground. My 47 Mercury had similar symptoms, 6 volt, positive ground, battery grounds to body, down to chassis them body to engine. Try a direct ground wire from battery to engine … solved my start issue

[Mountain Dew]

UPDATE

I received the NOS resister today. It measured .8 ohm also. Installed it and still only getting around 2.8V at the coil.

I jumpered the original resistor inline straight to the battery then straight to the coil. No switch or car wiring involved. I still only got 2.8V at the coil. There's nothing left.

What resistor value are you guys showing? I read somewhere on here that the resistor should be the same resistance as the coil's primary. Mine is .8 ohm.

I also ran another ground straight from the battery to the bell housing. I tried calling Skip but got no answer. I guess he's started the weekend.

[JayChicago]

Originally Posted by Mountain Dew

UPDATE
I jumpered the original resistor inline straight to the battery then straight to the coil. No switch or car wiring involved. I still only got 2.8V at the coil. There's nothing left.

I don’t have an explanation for this. I don’t know what’s going on. Both your resistors seem right to me. Did the battery voltage drop while you have been working and testing in the garage? Have you taken readings with another voltmeter to confirm?

2.8 volts is real close. If you are getting good spark, I would consider it good enough.

[marko39]

I too changed resistors because of 2.8 instead of at least 3 volts at coil. It made no difference and car starts very quickly with the 2.8 volts. Have a skip rebuilt coil after my new ( made in china) coil bit the dust after 20min. At least it was good for target practice.

[Mountain Dew]

I have 6.3-6.45 at the battery. I've tried different volt meters and get the same readings. This beats me. It fires right up every time. I guess I'll take it out and road test it.

marko39.......Are you running your car with 2.8 volts at the coil? Have you had any issues?

[aussie merc]

have you tried checking total resistance between the resistor input and the coil as you may have a bad wire or connection that is playing havoc with the voltage drop and often the longer you run the worst they get yet when checked cold show little or no extra resistance chasing them can be an absolute pain i always run them for at least 20 mins before checking trying to replicate how they work going down the road

[Mountain Dew]

I used a jumper to go from the battery to the resistor and a jumper to go from the other side of the resistor to the coil. Total resistance was still only .8 ohm and still getting about 2.8v at the coil.

[Mountain Dew]

I've been driving it around town and it is doing fine. I spoke with Skip and it's still a puzzle. I'll keep tabs on it but I'm not going to let it stop me from driving. I have other bugs to work out of it. Thanks for all the responses.

[JayChicago]

Good to hear its running well.

Thanks for posting the follow up. Always good for the rest of us to learn if/how a problem got resolved.