Pcmhomes

1947 Chrysler Windsor issues when hot

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When it gets hot after driving for awhile it starts to act up almost like it running out of gas but it isn’t.  It appears like it is putting an extra drain on the battery I thought the battery was bad so I replaced it same thing happens but seems to last longer today it stalled and cranked but wouldn’t fire I went picked up the old battery came back probably a total of 10-15 minutes later and tried starting it again without switching the batteries and it fired up.  Could this be the signs of a bad generator?  How to do I accurately test the output on it and if it’s even wired correctly?  What else could it be?  
 

back Story:  I have only had the car 2 months drove it twice since then but the old owner drove it an hour to my house after it had already been running for awhile.

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Where do you live?  Is hot outside like 80 degrees or more?  Sounds like the fuel is vaporizing (vapor lock) from heat making the car stall out.  Could be a weak fuel pump or the fuel line is too close to the exhaust line.  When the engine cools the problem goes away.

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I’m in Syracuse ny 80 outside but more like when the engine heats up for an extend period of time.  Today the longest I had it running consistently was about 30-40 minutes it really started to act up when I went up a couple hills,  I will check the routing of the lines.  Thank You!

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Really sounds like you are dealing with vapor lock issues. The fuel is boiling by the time it gets to the carb. Thank ethanol for that. Do you have anywhere you can buy non ethanol gas?

Many have installed an electric fuel pump inline and close to the tank and an electric switch to turn it on to prime the carb before starting and also when experiencing the vapor lock issues.

i live in NEPA, not far from you and experience the same issues sometimes when 80+ deg

 

Matt

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I like the idea of the electric fuel pump.  Today was the only time I have run ethanol in it because it started having issues and I wanted to make sure the tank was full and the station did not have Non Ethanol gas.  Thank You!

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Also: the fewer rubber fuel lines under the hood, the better, especially near the manifold and exhaust pipe.

Edited by keiser31 (see edit history)
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1 hour ago, jackofalltrades70 said:

Really sounds like you are dealing with vapor lock issues. The fuel is boiling by the time it gets to the carb. Thank ethanol for that. Do you have anywhere you can buy non ethanol gas?

Many have installed an electric fuel pump inline and close to the tank and an electric switch to turn it on to prime the carb before starting and also when experiencing the vapor lock issues.

i live in NEPA, not far from you and experience the same issues sometimes when 80+ deg

 

Matt

Matt couldn’t I keep the electric pump on  all the time connected to the starter switch to assist the mechanical pump.  I would have to put a pressure regulator in though So it doesn’t flood the carb correct?

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Correct. I always suggest the additional switch to avoid problems with over pressure. Have seen two nice cars catch fire under the hood because of too much pressure pushing past seats and flooding over the carb floats.  
 

with switch, you can turn pump on when vapor lock starts and turn back off when past problem. Also good for priming before cranking

 

I recommend a rebuild of mechanical pump.  
 

Matt 

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Didn’t take long to see the issue the line is almost touching the manifold and when they tightened it they twisted the line.

 

My question:  does anyone have pictures of how they routed the line?  Also how it’s routed to the rear because it goes up under the radiator which doesn’t make since to me.  Thank you for the help!

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Actually, going up under the radiator would keep it away from the engine heat.  Need to  find a way to run it on the frame rail, away from the manifolds and exhaust.

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1 hour ago, jackofalltrades70 said:

Actually, going up under the radiator would keep it away from the engine heat.  Need to  find a way to run it on the frame rail, away from the manifolds and exhaust.

Yes, and Chryslers of this era had a metal shield to deflect heat away from the fuel pump.  That might be missing on your car.

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34 minutes ago, TerryB said:

Yes, and Chryslers of this era had a metal shield to deflect heat away from the fuel pump.  That might be missing on your car.

Yes it’s missing it.  I plan on fabricating a shield for it.

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Pcm,

I just made a shield for my '31 Imperial fuel pump.

Took a piece of 14 gage and cut it 5" x 9".

Bent one end down 90 degrees x 1" which will go at the rear.

I had the 3 stand off pins on the fuel pump, so I put a dab of white paint on top of each,

and positioned the plate over the pump just how I wanted it to sit and pressed down on the pins.

Showed me right where to drill the 3 holes.

I'll post a picture tomorrow when the paint dries.

My fuel line comes off the front of the pump and vertically up and straight back to the carb over the intake manifold.

A pretty short run, but up here at 8500 ft. vapor lock is a way of life, so most of the older cars have fiberglass sleeves on their fuel lines.

And we all run electric fuel pumps mounted back at the tank and on a toggle switch straight to a hot lead.

Takes a lot of strain off the starter, when they sit for a week or so between drives.

AND you can kick it in  when she coughs on those long mountain pulls.

 

Mike in Colorado

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Pcm,

Here  you go.

Before, after paint and installed.

For your viewing pleasure..........

 

Mike in Colorado

P_20200630_093503_HDR_p.jpg

P_20200630_093200_HDR_p.jpg

P_20200630_094626_HDR_p.jpg

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In general I really detest electric pumps but understand why some resort to them.  If you're going to go that route, whether on-demand or constant-on, you really ought to have it wired through an oil pressure switch.  That will ensure that if the engine dies the pump isn't sitting there running.  This is especially important if you get a leak in the engine bay so that you aren't literally pouring fuel on the fire if something lights it off.

 

In the event this doesn't solve your problem start looking at the coil.  A failing coil can mimic vapor lock.  They break down when they get hot and come back to life when they cool off.  In many cases simply pulling the coil wire hot won't tell you anything since the voltage needs to be higher to jump the plug gap under compression rather than out in the open.  People see a spark even when hot, dismiss it, and keep chasing a gremlin that isn't there.

 

  

 

 

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I think there is a couple of things going on here.  Fuel delivery when hot is likely one issue. I agree new fuels evaporate when hot. It's worth investigating this further.  I had a couple of similar instances lately and I have found a few things are working.

 

I re-routed fuel lines further away from heat sources. I used temporary fuel injection rubber lines for now to test. So far so good. I plan to replace with steel lines, probably this winter during the off season. I also installed a 6V electric fuel pump. It is on a switch on dash so I can easily reach it. I only use it at select times. It is not on all the time. I use it to prime fuel lines and mechanical pump after sitting for a few days or longer. I flip it on manually after the ignition key is on, prime until I hear the pump slow down a little. Then turn off the pump and flash up the engine.  Then I run on my mechanical pump only. I drive around normally with my mechanical pump. There are a few long hills (5 minutes up hill) around here that I drive. I flip the pump on to assist when climbing these long hills. My throttle is pretty well wide open, so I am not worried about over-pressure. I keep a good sized fire extinguisher in the car handy if needed. So far no need!  I also acquired a phenolic spacer to install between the carb base and the intake manifold. This is designed to stop heat transfer up to the carb. This especially happens after a long hot drive and you shut the engine off for 15 mins. The heat climbs up the carb. The fuel in the carb bowl evaporates. It will be hard starting if at all, at this point. Here the electric fuel pump is used again. Forcing fuel back up through the system refilling the carb bowl. Push the accelerator to the floor. Open that throttle valve wide open and hold it there while cranking. Do not pump the gas pedal. Mine will flash up quickly when I do experience this heat soak. I have the phenolic spacer here, not yet installed. I hope to get it done soon. I also rebuilt my fuel pump and tested pressure. So I know it's good. All this has really made my car more fun and gets me home reliably. 

 

There is likely something else going on with the slow starter motor and battery symptoms. What size of battery cables you running? 1 gauge is the smallest I recommend. Both positive and negative. You need to get all the amps to the starter you can from your battery. Smaller battery cables create resistance of electrons. Slowing down the starter. Additionally, resistance causes the copper in the battery cables to get hot. Heat adds yet more resistance to copper as it gets hotter. You end up with a compounding problem and poor starter performance. Look at your battery cable mounts. Clean them up, they corrode. You may have a wiring problem that could be sucking down your battery, even while driving.  You can do a couple of things to find out. Get a digital multi-meter. Ignition key off. Charge your 6V battery with 1 cable removed. Measure voltage. It should be about 6.3 to 6.4-ish volts when fully charged.  Remove charger. Hook up battery to your car again, re-installing the one removed cable. Watch for a little spark. That's a clue there is a problem with a parasitic load. Should be no spark unless something is drawing power.  Leave your car overnight. Battery hooked up. Go out in the morning and re-measure your voltage. Should be close to 6.3V or so still. If not, you have something in the electrical system that is pulling away power, that should not be happening. This could also be happening while you drive too. Your generator is trying to keep up, but maybe it cannot, then after a drive you experience poor starter cranking.  Next thing you can do. Get a couple longer wires if needed. Run them to your battery posts.  Or just use the lead wires from your multi-meter. Secure them to their respective battery posts. Turn on your multimeter and have it sit on the seat next to you. Or in your lap. Somewhere you can see it. Select DC voltage setting. Should be 6.4-ish volts. Start your car. Watch the voltage drop and probably stay there. Go for a drive. Get your RPMs up. Watch the battery voltage climb back up.  If the generator is working, it will take the battery up past 7 volts while driving. If not, and you see voltage dropping,  you have a problem. Either a bad performing generator, or this bad wire/ground/parasitic load I mentioned.

 

In summary:

Heat means more electrical resistance, this happens naturally to copper wire. Border-line condition wires, may be past the point of being effective once they heat up. Yet seem to perform ok when cool again. Heat causes modern gasoline to evaporate at a lower temperature than old gas without ethanol in it. If you can get a grip on these issues, you'll be happier, and enjoying your car a lot more.

 

 

 

Edited by keithb7 (see edit history)

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Keith thank you so much!  A lot of great info, there is definitely some wiring issues and other quirks I need to get worked out, I assume I will be rewiring a good portion of the car this winter, the previous owner attempted to and cobbed a lot of it.  As far as the cables my diesel I use 2/0 cables will these be ok on this also?   I’m trying to learn as much about this vintage and the 6v system as possible to get it all worked out.  I really appreciate everyone taking the time and sharing knowledge with me!

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2/0 battery cable is big and might be hard to bend, but will work if you want to use it. 

 

Cobbling 6V over to 12V makes me shiver.  Most people have no idea.  6V in a flat head 6 cylinder old Mopar is completely adequate.  You just need to maintain the system, understand it if you can, and it will give you many decades more of reliable use. I own a 53 Chrysler and a '38 Plymouth. Both are stock 6V systems. They are pleasure cars. They rarely see poor weather or night time driving. I have no reason what-so-ever to consider either car for a 12V conversion. I built my own wiring for my 1938 re-wiring project. It's been fun, easy, and rewarding. I have not done all the wiring yet, but a large portion is new now. The original wiring is so crusty, stiff and unsafe. I've upsized all my wiring to keep good ampere flow. My lights are bright with new, clean, good grounds!

 

If you are serious about learning all about the 6V system I recommend some reading. I have been studying up for a few years now. I still pull out the old reference books to re-read again, and study further. Each time I grasp more info and retain it. I think I am 3.5 years now into my vintage car hobby. I have learned a TON of info in that small window of my life. I am far from done learning. I learn more every time I get out there and get my hands greasy, under the old cars.

Edited by keithb7 (see edit history)

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I definitely want to keep it 6v, it wasn’t being switched to 12v just the way he did the wiring was completely wrong, it works but has minor bugs I have to get worked out there is even lamp cord in one spot he used! I’ve worked on and owned mainly Muscle cars so it is a completely different animal but I enjoy learning all I Can about it.  Thanks Again!

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Pcm,

Just as an FYI, my daily driver, after coming home from Korea in 1963, was a '47 Windsor.

Kind of an olive green, with a rusty hood. We painted the hood flat black and painted a couple of palm trees on the driver's door.

Called her "Rommel's staff car". Drove that old girl to work and back plus a lot of vacations for 12 years.

Finally traded her for a '60 vette.

Worst trade we ever made !

 

Mike in Colorado 

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On ‎6‎/‎30‎/‎2020 at 3:24 PM, Pcmhomes said:

Thanks Mike!

 

I showed you mine, now you show me yours

 

Mike in Colorado

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Another suggestion. Be sure to have a good ground from the body and frame to the battery.  Just grounded to the engine might be an issue with rubber isolated mounts. Brighter lights and faster wipers for one thing. 

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