Q re: condenser failure
- Thread starter pdora
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zzlegend
Well-known member
A couple of weeks ago the weather was 103 to 107. On 3 different drives mine started missing in 3rd gear like it was running out of fuel. It idled fine, checked for fuel flow and it was fine. First thing i thought was vapor lock. I remember hearing somehwere that a condenser sometimes breaks down when it gets hot. I ordered a new one from Snyders and put it in. Have not had a miss since but the weather has only been high eightys to mid ninties, so we will see. Still have not ruled out the possible vapor lock issue. Mark.
Kurt in NJ
Well-known member
Yes, I have seen it, and had the problem on my car, it can seem like "vapor lock", idle fine, low power, seem like timing is off (backfire), there will be much arcing at the points (on engines that you can see the pointa spark it will look like a fireworks show)
My car came with a collection of condensers under the seat, I played with changing them, got very good at it --then I got the A&L condenser, now for 25 years I have not changed it.
The model A is a very good "tool" for learning diagnosis of automotive running problems because you can adjust the timing and mixture while you drive, feel and hear the result of the wrong settings ---how the lope of too rich is different than the lope of too much advance etc.
popping, sputtering, low power after short hot stop, then clear out, hard starting, points burned blue, heavy arcing points, --the weak condenser arcing the points can cause points problems,
combine a weak condenser with some carb mixture problems, add in a intermittant fuel flow problem and tight valve clearances and it can take a while to sort out --I just worked through this on a 42 Harley, plus all the owners attemps at fixin, the pressure washer water in the coil, the dist cam 180 out, the points side of coil hooked to headlight ---I was told that it ran perfect when parked a few years before.
My car came with a collection of condensers under the seat, I played with changing them, got very good at it --then I got the A&L condenser, now for 25 years I have not changed it.
The model A is a very good "tool" for learning diagnosis of automotive running problems because you can adjust the timing and mixture while you drive, feel and hear the result of the wrong settings ---how the lope of too rich is different than the lope of too much advance etc.
popping, sputtering, low power after short hot stop, then clear out, hard starting, points burned blue, heavy arcing points, --the weak condenser arcing the points can cause points problems,
combine a weak condenser with some carb mixture problems, add in a intermittant fuel flow problem and tight valve clearances and it can take a while to sort out --I just worked through this on a 42 Harley, plus all the owners attemps at fixin, the pressure washer water in the coil, the dist cam 180 out, the points side of coil hooked to headlight ---I was told that it ran perfect when parked a few years before.
Condensers can fail completely ( GO / NO GO) or they can "leak", (GO SLOWLY) meaning they will not continually hold the electricity that is sent to them. Most of the time when condensers are going bad, they will will work ok for a few minutes and then begin to fail as the engine warms up. The failure is not due to the engine warming, it is the condenser itself. Inside a condenser is a layer of conductive material much like aluminum foil placed on top of a layer of insulating material and both are rolled up like a sweet roll. The insulating material allows the condenser to take in and hold the electricity in the alumininum foil layer that is sent to it through the wire from the coil. The condenser case acts as the ground. When the insulating material degrades, the electricity will leak to the case and send the charge to ground causing weak or no spark.
JW
JW
MikeK
Well-known member
The very old wax or oil soaked paper condensers generally failed by going "open", loosing contact with the foil inside. There are actually four failure modes for capacitors. 1) Open, 2) short circuit, 3) drift of rating (usually loss) caused by internal corrosion or heat swelling, 4) internal electrical leakage, losing their high DC resistance. Modern capacitors (condensers) usually fail by number three or four progressing over time, culminating in 1 or 2, usually 1.
All modern manufactured capacitors, including the high temperature mylar jobs used for auto spark coils, have a rated service life. You can bet the cheap stuff in those tin-can automobile condensers is not to the same spec as capacitors used in communications satellites. Some people have condensers in their dizzy that have lasted 30+ years, but that is no guarantee about tomorrow. Then again, that applies to any part. Fortunately a spare condenser is small, light and easy to change on the side of the road. If you have the original points setup, not the ancient tech "modern" set, you do not have to mess with the points or even take off the cap & body to change it.
All modern manufactured capacitors, including the high temperature mylar jobs used for auto spark coils, have a rated service life. You can bet the cheap stuff in those tin-can automobile condensers is not to the same spec as capacitors used in communications satellites. Some people have condensers in their dizzy that have lasted 30+ years, but that is no guarantee about tomorrow. Then again, that applies to any part. Fortunately a spare condenser is small, light and easy to change on the side of the road. If you have the original points setup, not the ancient tech "modern" set, you do not have to mess with the points or even take off the cap & body to change it.
My last condenser failure was SLOOOOWLY. I was cruising down the road at about 40-mph, and the engine gradually lost power and stopped (over about a mile in distance). It would not immediately restart. It did however restart after the car had set for several minutes while I tried to diagnose the problem (didn't know at the time but condenser was cooling off, I think), but it again gradually lost power and stopped.
There was no missing, backfiring, etc. It was as if the gas had been slowly turned off. My first reaction was to look at the carburetor; which I removed, cleaned, and put back on. I also checked for gas line, sediment bowl, etc for flow, and all was ok. After reassembly, the car started fine, and drove as it should. Then a few miles down the road, the very same thing happened again. This time I trailered it home, and let it sit in the garage while I pondered the problem. When I went to try and start it, there was no fire at all; thus leading me to trouble-shooting the ignition system.
In the end, replacing the condenser solved the problem. So, in answer to your question Peter (as Mike has stated above); yes a condenser can fail slowly OR immediately.
There was no missing, backfiring, etc. It was as if the gas had been slowly turned off. My first reaction was to look at the carburetor; which I removed, cleaned, and put back on. I also checked for gas line, sediment bowl, etc for flow, and all was ok. After reassembly, the car started fine, and drove as it should. Then a few miles down the road, the very same thing happened again. This time I trailered it home, and let it sit in the garage while I pondered the problem. When I went to try and start it, there was no fire at all; thus leading me to trouble-shooting the ignition system.
In the end, replacing the condenser solved the problem. So, in answer to your question Peter (as Mike has stated above); yes a condenser can fail slowly OR immediately.
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Kevin in NJ
Well-known member
We need to add to this thread that condensers can be tested off the car with a coil- condenser tester.
Tom Wesenberg has a simple one that you can build from Radio Shack parts. Now if I could only remember the link to the build article.
Tom Wesenberg has a simple one that you can build from Radio Shack parts. Now if I could only remember the link to the build article.
Tom Endy
Well-known member
In 22 years of Model A hobbying I have seen countless numbers of condensers replaced, but I have seen only one that actually failed. My experience has been that the coil is more likely to fail, especially when the ambient temperature is above 100 degrees.
When you stop for gas in high temps the temps under the hood drastically increases. Coils are susceptible to high temps. Things expand and secondary windings can short out and give you fits with intermittent operation. Quite often people mistake this for vapor lock.
Tom Endy
When you stop for gas in high temps the temps under the hood drastically increases. Coils are susceptible to high temps. Things expand and secondary windings can short out and give you fits with intermittent operation. Quite often people mistake this for vapor lock.
Tom Endy
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zzlegend
Well-known member
Tom. This also crossed my mind. My coil never feels warm and is not leaking any crude but thats not to say it isnt going bad. I have no hood on my beater also. That might be a plus on hot days. Time and a few more drives on hot days will tell. Mark.
700rpm
Well-known member
On a long road trip in an unrestored A about 40 years ago my condenser failed. The flat wing had come off the round part. I was in the middle of nowhere. But I had some electrical tape; so I taped the flat part back on and reinstalled the condenser. It got me another 300 miles or so before I could get a replacement.
This is one reason I love these cars. Just about all you need to keep them running is bailing wire, spit, and faith. And occasionally some electrical tape.
This is one reason I love these cars. Just about all you need to keep them running is bailing wire, spit, and faith. And occasionally some electrical tape.
zzlegend
Well-known member
You said it right 700. I little piece of bailing wire makes a great plug wire.
I carry a roll for all needs.
700rpm
Well-known member
A friend just had a "bailing wire" moment. He stopped on a short drive in the country to check on things. In the process, he broke one of his spark plug connectors. He wandered into a nearby field and found some 14 gauge single strand wire, came back to his car, hooked it up, and away he went. He says he's going to leave it like that! It runs fine!
Tom Endy
Well-known member
The one failed condenser I observed in 22 years of Model A hobbying that I spoke of in my earlier post was also the ground strap unattaching inself from the body of the condenser.
The owner had been driving the car with the spark handle all the way up and the exhaust manifold became cherry red and melted the solder on the strap end of the condenser. This allowed the strap to spring away from the body.
Most of the good suppliers, such as Bratton, carry a condenser that has the ground strap attached better. There are three little dot indentations visible on the end of the strap. I believe they may be stake welds. This type of condenser will withstand the heat from the manifold.
There are still suppliers carrying the ones that will melt and fail. These are easily identified. There is a circular hole about 1\4" in diameter at the end of the strap and is filled with solder. This type is best avoided.
Tom Endy
The owner had been driving the car with the spark handle all the way up and the exhaust manifold became cherry red and melted the solder on the strap end of the condenser. This allowed the strap to spring away from the body.
Most of the good suppliers, such as Bratton, carry a condenser that has the ground strap attached better. There are three little dot indentations visible on the end of the strap. I believe they may be stake welds. This type of condenser will withstand the heat from the manifold.
There are still suppliers carrying the ones that will melt and fail. These are easily identified. There is a circular hole about 1\4" in diameter at the end of the strap and is filled with solder. This type is best avoided.
Tom Endy
Kevin in NJ
Well-known member
A&L had the early burn out proof condensers built with soldered on tabs. My brother mentioned this to A&L at Hershey a couple of years ago and they just handed him one with spot welded tabs.
Keep in mind his field repair of just bending the tab to contact the condenser work for a few years until he replace the it.
We had many condensers go bad over time. A lot them were the old production type. We have a coil condenser tester and verified them as bad.
The burn out proof condensers you buy today have not failed, unless you have a soldered on type.
Keep in mind his field repair of just bending the tab to contact the condenser work for a few years until he replace the it.
We had many condensers go bad over time. A lot them were the old production type. We have a coil condenser tester and verified them as bad.
The burn out proof condensers you buy today have not failed, unless you have a soldered on type.
zzlegend
Well-known member
Just checked the two that i bought from Snyders. They have the three little dot indentations in them. One is in the car the other is in the toolbox as a spare. Mark.