1929Chrysler Posted June 6, 2008 Share Posted June 6, 2008 I've had some issues trying to work the bugs out of this car so hopefully someone can help. A while back I had problems with the vacumm tank. We thought it was the carburetor so we put a rebuilt one on and had the same problem with sputtering and stalling. Once a new vacumm tank went on that problem went away. Also had/have problems with my radiator being clogged. After rust from the engine getting into the radiator I had some over heating problems. After many flushes I finally got it to stop over heating in cooler weather. (I am currently having a radiator recored)So today just for giggles I thought I'd run the car in this 90 degree heat to see if it would over heat. After a couple of minutes with the car just sitting and idling it would stall out.I thought great! I have vacumm canister problems again. I took the canister out and filled the outer tank with fuel and ran the car. Same thing. It would stall. I removed the glaas bowl to see if any setiment was obstructing the passage to the carb. I didn't see any. The one thing I thought was strange was that when I replaced the glass bowl and opened the valve to let the fuel drop down from the canister, it only came down in tiny dribbles. Only when I loosened the glass bowl holder to let air in did it come gushing down like it normally would??? Is this normal?I drove this car the other day in cooler weather and it ran perfect for hours. The only thing I can think of is vapor lock??? The fuel line from the canister to the carb is about 1 1/4" from the manifold. Too close? Suggestions??Incidentally, when the car would stall, I would add a little extra fuel to the canister and after a few minutes it would fire right back up and run great for a few more minutes and then stall out again. Am I barking up the right tree or should I consider looking at other things??Thanks in advance!Dan Link to comment Share on other sites More sharing options...
Mark Shaw Posted June 6, 2008 Share Posted June 6, 2008 Dan,You can test your theory simply by putting ice on the fuel line to see if it solves the problem. If it does, you need to re-route the fuel line or make a heat shield for it. Link to comment Share on other sites More sharing options...
hchris Posted June 7, 2008 Share Posted June 7, 2008 OK how about this, at the point when it dies on you, can you quickly turn off the fuel from vac tank to carb, then take the top off the carb float bowl to see if there is any ( or correct level ) fuel in the bowl. If you find little or no fuel in the bowl then you have a fuel feed problem, if on the other hand the carb bowl is full then you can start down the vaporising fuel trail. If vaporising is the issue you might consider insulating the fuel lines in some manner rather than moving the vac tank. For what its worth I have a 25 Maxwell with vac tank directly above the exhaust manifold & I have yet to experience vaporising problems.CJH Link to comment Share on other sites More sharing options...
1929Chrysler Posted June 7, 2008 Author Share Posted June 7, 2008 Thank you hchris and Mark.. Two very good suggestions. I will try both. I suspect the engine is running hotter than normal because of the radiator problems I am having.I have also heard that copper fuel lines "hold" heat a lot more than steel lines. I would hate to change over to steel as it isn't original and either is insulating (to the best of my knowledge) Any body out there familiar with originality on this car?It's a shame the fuel today evaporates quicker than the fuel formualted back then.Dan Link to comment Share on other sites More sharing options...
1929Chrysler Posted June 8, 2008 Author Share Posted June 8, 2008 hcchris. The more I think about your suggestion the more I get confused. If I'm not mistaken, if vapor lock were to occur in the fuel line between the vacumm tank and the carburetor (because that fuel line is right next to the manifold)that would esentially disrupt the fuel supply to the carb. If the carburetor is becoming starved because of that how would the float bowl still be filled if there was a vapor lock problem? It would seem there would be a lack of fuel in the fuel bowl if that were the case?? Am I wrong here???I have heard of vapor lock occuring within the carburetor but as they say... Heat rises and the carburetor is below the manifold so I would'nt think vapor lock is occuring within the carb. But I have absolutely no experiance in this area which is why I am asking the pros!!!Thanks Dan Link to comment Share on other sites More sharing options...
hchris Posted June 8, 2008 Share Posted June 8, 2008 OK Dan not wanting to confuse you,I am suggesting that you either have a fuel feed problem or a vaporising problem as two seperate issues.First, and I suspect that this is most likely, you may have a fuel feed problem for a variety of reasons. The best way to check this is when the engine dies you need to immediately lift the top of the carb bowl and see what the fuel level is, ie can you identify whether the engine has stopped due to lack of fuel. To achieve this you will need to shut off the vac tank / carb tap to remove the possibility of fuel running into the carb whilst you are undertaking this task. In the event this is the problem then you obviously need to find the solution - has the vac tank got sufficient fuel ? as someone else suggested, are the vents to vac tank and filler cap clear etc.etc.Second, vaporisation - the original lines were copper tube and as you say run in close proximity to the exhaust. It is possible that these lines are vaporising but more likely that heat soak through the manifold and within the engine bay is enough to cause the fuel in the carb bowl to vaporise, the only way to prove this would be insulating the lines and maybe a heat shield for the carb. As I understand it the car runs OK on a cooler day ? this in itself would point to vaporisation, or was it just coincidence ?So first up try and establish if it is running out of fuel, if not then see if you can keep the heat off the carb and fuel line.CJH Link to comment Share on other sites More sharing options...
1929Chrysler Posted June 8, 2008 Author Share Posted June 8, 2008 Thanks hchris.. I will try your suggestion. Just to clarify. I took the "inner" vacuum canister out of the outer tank and filling the outer tank manually with fuel I am using it as an auxilary tank. So Vacumm vents and and anything to do with the vacumm canister assembly are not an issue now.Thanks again for the reply. I'll let you know how I make out!Dan Link to comment Share on other sites More sharing options...
ex98thdrill Posted June 10, 2008 Share Posted June 10, 2008 Dan,We had the same problem with our fire truck. We put foil on the fuel lines, clothes pins on the fuel lines, added an electric fuel pump, more new spark plugs, more plug wires, upgraded the generator (to rule out electrical), and spent almost all summer trying to figure it out. After spending most of the summer going nuts on the thing and several hundred dollars later the problem turned out to be a combination of two things.1. Coil - the coil was breaking down when the engine got hot. The hotter the engine got, the quicker the problems arose. We went to NAPA (often stands for <span style="text-decoration: underline"><span style="font-weight: bold">N</span></span>o <span style="text-decoration: underline"><span style="font-weight: bold">A</span></span>uto <span style="text-decoration: underline"><span style="font-weight: bold">P</span></span>arts <span style="text-decoration: underline"><span style="font-weight: bold">A</span></span>vailable) and bought a brand new coil with a lifetime warranty for $75 and mounted it next to the original Ford factory coil. When the truck gets point judged, we hook the wires back into the original coil and then take the NAPA coil out. 2. Gas Cap - We bought a brand new gas cap from Dennis Carpenter. When the truck got hot (about 20 minutes) it would start acting up. It turns out that the gas cap wasn't vented, so we drilled a small hole in the gas cap and this helped a lot.- In both cases it wasn't one thing, it was a combination of two things that solved our problem. If you replaced your gas cap with a new one, put the old one back on and try running it. Try swapping out your coil with one that is either new or off of another car that works. - I hope this works out for you. I can honestly say that I've driven down that road and can easily feel your pain. Link to comment Share on other sites More sharing options...
hchris Posted June 12, 2008 Share Posted June 12, 2008 PHD - your summary is technically correct re increasing fuel pressure to reduce vaporisation, however, those of us with vac.tank vehicles should be aware that our fuel systems were designed to run on 0.5psi delivery pressure. As the average electric pump is designed for 3-5psi you stand the chance of creating more problems than you set out to cure.Whilst there are certainly vehicles out there with inherent vaporisation problems by design, a properly maintained vac. system is quite capable of dealing with todays fuels; my own experience with a 1925 Maxwell, in summer temps well into the high 90s, using 91 octane bear this out.By all means consider the easy fix with an electric pump but just be aware you may be creating more problems than you started out with and you may still have a feed problem.CJH Link to comment Share on other sites More sharing options...
1929Chrysler Posted June 12, 2008 Author Share Posted June 12, 2008 Well, I figured out my problem. I ran the car just as earlier described. After a good 45 minutes of idling on an even hotter day than the first time, nothing happened!! I was begining to think my vapor theory was all wrong. Which it was. FINALLY the car began to sputter and stall. Right away I shut off the glass bowl valve and checked the float level in the carb. It was low. I worked my way up to the outer fuel canisterand shined a flash light down and could see a piece of dirt obstructing the flow to the glass bowl.Apparently, the piece of dirt would float up out of the way when the car was shut off which would explain why it would start right back up. Any way, I cleaned the canister out, re-installed the inner canister and ran it for an additional 45 minutes with no problems. No vapor lock today!!I have what's called a red head which is a high compression head. That along with my radiator problems made me sure to believe it was vapor lock. Had fun learning about it anyway!!Dan Link to comment Share on other sites More sharing options...
hchris Posted June 12, 2008 Share Posted June 12, 2008 Well done Sherlock, sometimes its just the simplest answer but so frustrating !!CJH Link to comment Share on other sites More sharing options...
ex98thdrill Posted June 12, 2008 Share Posted June 12, 2008 I wish that was all that it had taken to solve our problem. In either case you got some other solutions and ways to try, and you know what worked for us. The important part is that the car is running well, and it didn't cost a ton of money to figure out the problem.GOOD FIND!! Link to comment Share on other sites More sharing options...
1929Chrysler Posted June 12, 2008 Author Share Posted June 12, 2008 ex98thdr.. I was down that road last year with the coil working OK when cold and when hot experianced the same problems you described. I was lucky to find an N.O.S. coil to solve the problem. Half the fun with these old cars are trying to figure them out.Anyway, thanks to everyone's suggestions out there. I really appreciate your help!Dan Link to comment Share on other sites More sharing options...
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