Guest Arrowhead Posted June 14, 2012 Share Posted June 14, 2012 I've had my 55 roadmaster for about a year, finished restoring it in august last year. I was having troubles with overheating. on hot days the car would die when going downhill and I would have to wait 20-30 minutes for the car to cool down and then it would start and run again. I had the fuel tank cleaned and coated, replaced an aftermarket fuel pump the previous owner had mounted near the engine to an electric one mounted in the back near the tank and I replaced the pickup tube and sending unit in the tank. Didn't help, ended up being a float level adjustment in the carb that cured the problem. On hot days the car would overheat a little, but it was fall and I let the problem go and only drove on days under 80 degrees. This took me through the winter with no problems. I drove the car 1-2 a week. Now that summer has arrived, the car was overheating again. I replaced the thermostat three times with no luck. The radiator had already been cleaned and coated so I replaced it with an aluminum cross flow radiator this weekend. I just took it out yesterday for a test drive. I drove for about 20 minutes, all the time the temprature stayed below normal. Sweet! then all at once it started to sputter. The more I tried to give it gas the more it sounded like it was starving for it. It eventually died. I waited a minute and started it again. Drove a couple of blocks and it did the same thing. I could start it and idle just fine, but as soon as I give it gas it would choke, wheeze and die. The outside temp was about 90 degrees, and I live at about 5000 ft above sea level. Is this a vapor lock issue? or possibly a coil problem. Anyone have any input? I don't know if I need a new carb (the old one has been rebuilt already). I'm confused as to why this would happen now that the overheating is fixed and it didn't happen at all when the car was overheating last summer. Is it possible I need a higher pressure fuel pump?My dad's 56 caddy is having the same issue too. He's already replaced the carb and his car has never overheated. What's the deal? Link to comment Share on other sites More sharing options...
jackofalltrades70 Posted June 14, 2012 Share Posted June 14, 2012 You haven't mentioned a fuel filter anywhere in your post. Spitting and sputtering usually is related to lack of fuel. Matt Link to comment Share on other sites More sharing options...
old-tank Posted June 14, 2012 Share Posted June 14, 2012 What carb do you have: the carter wcfb or the rochester 4gc? What is the rated output of your electric fuel pump at the tank?Willie Link to comment Share on other sites More sharing options...
Guest Arrowhead Posted June 14, 2012 Share Posted June 14, 2012 It's the rochester carb. The fuel pump is 5#. and yes, it has a new fuel filter. Thanks for any help. Link to comment Share on other sites More sharing options...
old-tank Posted June 14, 2012 Share Posted June 14, 2012 Check the fuel pressure at the carb. I have a 7-9# installed at the tank and and have a little over half that at the carb.The Rochester 4GC is junk! Our currently available ethanol laced fuel will dissolve the cement on the bowl plugs which can leak and catch fire. Also the ethanol fuel when it dries in a carb will leave a white powdery residue. That is what seems to clog the 4GC: rebuild it, install and it performs just fine; let it sit for a week and you will have poor idle, stumble, surging until you disassemble and clean again. The Carter WCFB seems to tolerate drying much better.Willie Link to comment Share on other sites More sharing options...
55 SURVIVOR Posted June 15, 2012 Share Posted June 15, 2012 How is your coil resistor block? Link to comment Share on other sites More sharing options...
Guest Koala Posted June 15, 2012 Share Posted June 15, 2012 May not be your problem but I have heard reports that the new ethanol based fuels will dissolve those fuel tank coatings.Koala Link to comment Share on other sites More sharing options...
Pete Phillips Posted June 15, 2012 Share Posted June 15, 2012 Sounds like vapor lock to me. I am having the same problem with my 1950 Roadmaster. Put some wooden clothes pins on the metal fuel line near the engine, and/or wrap the fuel line with insulation of some sort.Pete Phillips Link to comment Share on other sites More sharing options...
Guest shadetree77 Posted June 16, 2012 Share Posted June 16, 2012 Wrap the fuel line with insulation of some sort.Here's something to wrap the fuel line with. I used it for my choke stove pipe but it says it's "Also excellent for wrapping vapor locked fuel lines". Be warned though, it's not white like in the picture. It's a pale yellow color so it really stands out under the hood. They sell it by the foot. Good luck with your problem and make sure you let us know if you solve it. I've been having a somewhat similar problem with my '52. Only difference is, it only stalls like that when I make a sharp turn.CARS. Inc. - Insulator Material Link to comment Share on other sites More sharing options...
old-tank Posted June 16, 2012 Share Posted June 16, 2012 Clothes pin, insulation, rerouting the line between the mechanical lift pump and the carb did nothing for my 55's. The vapor lock is between the tank and the pump. Only a 7-9# electric pump (which will give 5# at the carb) mounted at the tank will work.The vapor lock is between the tank and the pump. That's on the suction side of the mechanical lift pump...the pressure side will push fuel and vapor into the carb. Willie Link to comment Share on other sites More sharing options...
Guest Arrowhead Posted June 18, 2012 Share Posted June 18, 2012 I replaced the coil... no luck. too much month left at the end of the money. I will probably try the carb next month. In the mean time, I'm second guessing myself on the fuel pump. I think it's a 7-9# fuel pump....or is is a 5#? Better check and see about that too. Link to comment Share on other sites More sharing options...
55 SURVIVOR Posted June 19, 2012 Share Posted June 19, 2012 Did you check the resistor[fastened on the fire wall,ceramic] it regulates coil voltage. Link to comment Share on other sites More sharing options...
60FlatTop Posted June 19, 2012 Share Posted June 19, 2012 Last summer, shortly after tuning my "60 Buick up, the wire fell out of the end of the condenser; just more cheap junk delivered by ship. Condenser problems can be heat related as well. Pick up an old stock one on Ebay or from an old distributor and change yours our if it is fairly new.Bernie Link to comment Share on other sites More sharing options...
Guest 54fins Posted June 27, 2012 Share Posted June 27, 2012 good idea. I mounted one of those facet pumps from NAPA behind the radiator and have had good luck. But duhh- it's still hot as hell anywhere near the engine, and you may even be pulling a slight vacuum before the pump. The further back towards the tank, the better. I think you noted one of those obvious things that explains why a lot of old cars are still vapor locking with an electric fuel pump! Link to comment Share on other sites More sharing options...
buick man Posted June 28, 2012 Share Posted June 28, 2012 Arrowhead: Before you start throwing parts around, go and buy yourself a 5 gallon can of clean racing fuel, being careful to select the one that is pure gasoline with no oxygenators added. (ie alcohol based ) . Then, drain your tank and fill with the racing gas. Start the car up and turn the idle jets in just 1/8 a turn or so. Then go drive it on a hot day. I think you will be surprised. Link to comment Share on other sites More sharing options...
bhambulldog Posted July 5, 2012 Share Posted July 5, 2012 Shortly after restoration;Mine would heat up and stall due to lean fuel mixture. I replaced two fuel filters before all the trash in the tank was filtered out. The third filter was the charm. It's been on there for ten years , now Link to comment Share on other sites More sharing options...
Guest Arrowhead Posted July 10, 2012 Share Posted July 10, 2012 I installed a 9# fuel pump back by the tank, instead of the 5# that was on there. I've been driving it all weekend in 100 degree weather with NO vaporlock. Thanks for the help everyone, I think this project is complete. Now I can get started on the next project - 1941 GMC truck. Link to comment Share on other sites More sharing options...
old-tank Posted July 10, 2012 Share Posted July 10, 2012 "I love it when a plan comes together" Link to comment Share on other sites More sharing options...
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