VCCA Home Forums TECHNICAL - 1945 AND NEWER 1946-1948 1946 update

Posted maybe 2 weeks ago...thought I had vapor lock..thanks to the advice of you fine people and reading many posts, I don't think it was vapor lock at all. ( my car ran horribly on the way home from a car show that was 40 miles away...hitting, missing, acted like starved for fuel ) I installed new plugs, plug wires, coil, dist. cap, rotor, condenser, points. Went to a car show today about 40 miles each way. Car performed flawlessly !!!! Thanks to Chev's of the 40's and Jim Carter and again you awesome experts. Obviously I fixed it. Yay for me.

update....on Saturday the 24th went 140 miles round trip to a car show...car ran flawless ! Next day started out to another...got 15 miles from home...car lost power and just DIED !! Had to have her towed home. I am going to check the coil and condenser ...I have not a clue as to what to do, what readings I should be getting, etc. I do have a nice tester that will check DC, AC and ohms. Could someone please explain , in VERY SIMPLE terms what to do. At this point I have both the new and old coils sitting on my work bench. I did test both...the new read 20 on ohm scale and the old read 5 ( the dial was on X1K ) whatever that means. I know nothing about electricity and am ready to pull my hair out. Thanks for any help !

When the engine dies have you checked to see if you have spark at the plugs or gas in the carburetor?

going to check that too......just have to start checking everything....

What did it do and/or sound like when it quit. Just slowed down until engine died? Quit just like you turned off the key? Popped or coughed or sputtered? Those are all clues to what might be the problem.

Immediately when you have a problem: Check for gas in the carburetor. Take off the air cleaner and activate throttle while looking down the throat. Do you see gas squirt? If the accelerator pump works and there is gas in the carburetor you should see a squirt.

Next check for spark by removing the coil wire from the distributor cap and either turning over the engine or manually working the points. If the points are closed just open and close while holding the end of the coil wire 1/2" from a ground (engine block, side cover bolt or ?) If open short across the points with a screwdriver, wire, pliers, hair pin (careful as the hair pin will heat up). See any spark? Hear a "snap"? If you have a good spark you should be able to hear it.

If your engine has gasoline, spark and compression it should run and continue to run. If one is missing or weak then it may not run.

It started missing, then slowed down and DIED ! ugh Thanks...yes I will be checking these things over the weekend....will let you know....I had someone tell me it probably was the coil cause it was so sudden. Of course I want to check that too and the condenser. Thanks.

I will check for fuel 1st. I don't quite understand your next paragraph about coil and sparks. It sounds like you hold the wire 1/2 ' from engine block, crank engine and look for the spark to " jump " . That is how I understand your explanation. I might need some clarification. I am sorry but you have to pretend I am 6 years old and explain everything in detail. I hate automotive electrics and don't understand it at all. Thank you for your help and patience. I have worked on cars for years, but NEVER had 1 that has given me this much trouble before...it must be a jinx.

Yes you hold the distributor end of the coil wire 1/2" from the engine and then open and close the points. Just remember that the points are only a on/off switch. You can either turn over the engine to check the spark (that can be with the distributor cap on or removed) or manually operate the points (must remove the distributor cap to get to the points). To manually operate the points just open and close them by pulling on the moveable arm and then let it spring back. That is if the points are closed. If not closed then rotate the engine by rocking in third gear, bumping the starter. Some grab a fan blade and pull on it to rotate the engine. That is not recommended as it can stress a fan blade so it might break later.

If you don't get a spark that will jump ~ 1/2" and also make a "snap" then you will need to check further. The condition of the points can be checked by manually open and closing as described above and then by putting an insulator (piece of dry paper, plastic, etc.) between the point contacts and shorting between the point arms with a screwdriver, pliers, wire, coin, etc. If you get a stronger spark by shorting compared to opening and closing them then cleaning the points is necessary. Point file, wife's emery board, fine sand paper or other abrasive can be used. Just make sure to wipe them to remove any remaining grit.

If the spark is the same by open and closing and shorting then check the condenser and/or coil. Since checking a condenser requires equipment not generally available it is best to replace with one known to be good. Just because they are new doesn't guarantee they are good. Yes, most of the time new condensers are good but not 100%. The coil can be checked with a meter to determine the resistance of each winding and if either is grounded. If those tests are okay it still doesn't mean the coil will not fail at higher temperatures.

Thank you !! Ok...points are brand new....I will check this and compression next week when I have a friend come over to help me. What should I hold onto this coil wire with to avoid shock / Oh BTW...I am YES getting fuel from the pump to the carburetor !! I had to do this myself ( no one to watch or help ) ...undid fuel line , twisty tied a plastic bag to the end of the line...hit starter for a few secs. Voila !! Fuel in bag. So cross fuel problem off the list. Thanks.

If the engine is running OK right now the tests are meaningless. Must be performed when engine quits running.

It is NOT running yet. All I have figured out so far is I am getting fuel to carb. The short story is after lots of new electrical parts listed in my previous post it ran great for 2 weeks, then suddenly died on the road. So going through all this trouble shooting.

Check "thin" wire running from the coil to the side of the distributor. Sometime there is a break in the wire inside of the insulation.
Does the car still have the polarity reversing switch mounted on top of the starter? Then there will be two wires running from the switch to the distributor.

More often than not new points need to be cleaned to work correctly. Apparently either storage corrosion or other coating (maybe preservative) needs to be removed. I now routinely clean even new points prior to installing.

Thanks...will check those wires too and re clean points. . Yes I have the polarity reversing switch.

From my own personal experience try bypassing the reversing polarity switch. Mine would run just fine and then just die. Then it would start right back up and maybe run fine for the rest of the trip. Finally one day it died and would not restart. I always thought it was a gas issue. I called a friend who worked for a dealership and he came to my rescue. He rips off the air cleaner and puts his hand over top of carb and tells me to crank it over. He said it is not a gas problem. He proceeds over to the other side and looks down in and sees the switch and immediately says there is your problem. He had me take him to his shop, get jumper wires and the car started right up and has run like a charm ever since. They are a problem.

To disconnect the reversing switc remove all present wires.
Run a wire from the coil to the terminal on the side of the distributor just above the grease cap.
Then it will be necessary to ground the dist. plate. this is done by running a ground wire from the terminal on the other side of the dist. to a screw on the push rod cover or any other ground you prefer.

The intended purpse of the polarity reversing switch was to reverse theflow of current through the points eachtime the engine was strated. This was to increase the life of the points.
The switch was used from 1941 through mid 1948. Distributors used on these models used a different set of points than the ones with out. The 1934-1940-late 1948 and up to 1962 used the same points with a more compact set used for the reversing set models. Condensers were the same for all.

Oh Lord....ok I have read about these switches...sounded like they were more trouble than they were worth. Whew.....will try that. Keeping everything crossed that I can.

Yes..when I ordered my parts from Chev's of 40's had to make sure I got the correct set of points to fit...and Rusty love your convertible. Thanks experts.

I mean Shorty...sorry

Ok..cleaned points, took off reverse polarity wires and ran wires as per instructions. I used garage door opener wire I had...it is copper and has 2 wires in it. Is that ok ? Now I have no spark. Ugh !!! Check condenser and coil next ?

Using a test light, with the ignition on you should have power at both ends of the thin wire running from the coil to side of distributor and power to the moving point arm and no power to the stationary part of the points when the points are open.

Okkkkk can I use an ohm meter for this ? I don't have a test light...this [bleeped] is all new to me. Sorry to sound so stupid...I am almost pulling my hair out...and I am bald. This is very frustrating and pissing me off. Thanks for the help all.

Hi,

I'll be the first to admit that I do not know much about the newer (1940's) vehicles. My world is in the late 1920's.

But I can add a few thoughts, having read the entire thread.

Clement, to answer your last question, yes, you can use the multimeter instead of a test light. Set it up to read DC voltage (probably in with the 10 volt range) and then you can touch one lead to ground and the other lead in the spots where you are looking for power. Follow the advice of those who have comment earlier.

I suggest you work methodically going from the battery, to the switch, to the power line going to the coil, etc. If you get to a point that should have power and it does not, you are closing in on the problem.

All of this troubleshooting is detective work. Follow the clues until you find the culprit and then fix the problem.

I noticed a couple of things at the top of this discussion. Many people replace a whole bunch of things at once and the problem goes away for a while. When the problem rears its head again, there is a lot of frustration because 'they are all new parts!'

Take your time to tackle one possible problem at a time. For example, you said that you have proof that there is gas getting to the carb. Great! The next thing to check is to see if the gas is getting through the carb and into the cylinders, as per a previous post (looking down the throat of the carb, moving the gas lever, and looking for a squirt of gas).

The gas issue should be put to bed before jumping into the electrical stuff. Maybe there is a filter on the carb itself that is clogged. I don't know.

The point is, work on one thing at a time, eliminate a possibility one item at a time and then you can confidently move forward to find and fix the problem.

My 2 cents.

BTW, don't forget to have fun. Put on your Sherlock Holmes hat and say, "The game is afoot!".

Cheers, Dean

Thanks Chevgene and Dean. Ok..I bought a test light. Gasoline....I undid the fuel line from carb fitting, twisty tied a plastic baggy onto the open end...cranked engine a few seconds...there was fuel in the bag. Also hand operated throttle...there was a small line of fuel squirting into carb. So, I am pretty sure the fuel issue can be put to rest unless I am missing something.

Thursday or Friday I will go about testing the electrical item you both and Shorty too suggested.

What about the ignition switch ? Wouldn't that factor into this somehow if it is going bad ?

Thanks all for the great help. I just know I am really frustrated. When I am supposed to be enjoying the car I am pulling my hair out. My 1950 I have owned for 3 years...never given me 1 problem...this car is another story.

Oh...LOL when I was investigating the fuel issue, discovered the choke knob wasn't even pulling the choke to close properly....fixed that and also adjusted the throttle cable properly...maybe a silverlining in there somewhere. What's funny is I never used the choke at all...hit the pedal 2 times, hit starter and it fired right up, which I always thought was weird......it worked....but to me unusual.

Ok...will let you know what I find out. Sherlock Holmes to the antique Chevrolet rescue, here I come.

ok...my test light states " for use with power off "....so I did not turn on the ignition...everything tested exactly as Chevgene said. So I guess that is good.....for the heck of it I connected clip of test light to small connector at top of coil...touched probe to each spark plug...the test light lit !! So, I am guessing that is good. Tried to start..engine turns over, but of course NO starting. Doesn't even want to " catch", if you know what I mean. Now what if you please ?

It could be flooded due to all the failed starting attempts.
Let it sit untouched for a day and then try it pulling the choke closed for the first 3 seconeds of cranking over.
Did you forget to install the rotor?
Are the spark plugs sparking? Remove a spark plug and reconnect the wire . When you turn on the ignition and hit the starter you should see a spark jump in the plug gap with the plug grounded.

ok..rotor is in it. Will check spark. If I have no spark then what ? This will sound dumb...where does the spark come from anyhow ? What about the ignition switch ? If it is going bad how does that figure into the equation ?

While possible the ign. switch is about the last thing on the list to prevent starting. If you have power at the coil when the switch is in the on position the switch is OK.
Checking the spark plugs for sprak will will narrow the problem down. If there is spark and gas the engine should run.

I see. ok thx !

Pulled # 1 spark plug and reattached wire. set on top of valve cover. Put a mirror ifo so I could see reflection of spark from driver seat. I cranked the engine for about 4 to 5 seconds at a time for 4 times. Got spark for about 2 seconds of that time. Now what ? Thanks.

This is like to diagnose a medical condition over the phone.

Have been giving this more thought. You mentioned, could the ignition switch be bad....After thinking it over the actual switch may be fine but if the car has the original eletrolock(cable enclosed switch wires) the wire inside the armoured cable may be shorting out.
My test would be remove the wire from the coil and run a new wire from the battery cable connection on the starter to the coil. This will by pass the cable wires. If the engine starts them problem is inside of the cable.....problem-to shut off the engine off the wire will need to be DISCONNECTED.

Yes it is crazy with all this diagnosing !!! Yes...it has the original electrolock. Ok...I can try that test...so you are saying if this test works, to shut off the engine I need to undo the wire ? ( because it isn't hooked to the ignition ) Then I can run a new wire through the electrolock cable and everything should be ok ? haha Thanks !!

I had another thought....I can undo the wire and pull it out of electrolock cable and see if any bad spots and/or just replace it.

The Electrolock is a whole project unto itself and is not quite as easy to replace the wire as it may initially appear.

Try Gene's method to bypass the electolock and go from there. You will need to disconnect the replacement wire to shut the engine off if it starts.

Ohhhhhhh...great..ok well how do I disconnect that replacement wire without getting shocked ?

Just keep up your SPRITS and make belive that you are hunting for a GHOST.......

Check his profile for that one.

There is not enough current to give you a shock.
The spark plug high tension wires will do that.

Ok...that's good !! Thanks...will have time Saturday afternoon to do this hopefully. Will keep you posted.

Ok...that didn't work. The only think not tested yet are coil and condenser. I am at a complete loss here.

Now I have a whole new issue...went out Monday morning to undo all the " test and bypass " wires...the coil was so hot I could hardly touch it.

This indicates that the coil (ignition) was not "turned off" .

This could also have caused the points to burn also if they were closed..

ugh I took off all the" test and bypass " wires...it's ok now...finally cooled...will test condenser later on...if anybody has any helpful ideas I will take them...I know you are all tired of me by now...

I gave up, had car towed 2 blocks to a nice old fashioned repair shop by my house. Both the original coil and the NORS coil I bought on ebay were bad. Plus I screwed up when I installed the points. Did something weird with the spring. They have a nice 6 volt coil on it, purrs like a kitten. Eventually will get one like original. That is all. Thanks.