rls120 Posted October 19, 2012 Share Posted October 19, 2012 It dies (acts like its running out of gas) after a few minutes driving. Won't restart. Wait 30 seconds or more, and it starts right up and takes off. Until next time. Does this at temps ranging from 50-103 degrees. Has been doing it since I got the car in July: I still haven't been able to drive it off of my own property (fortunately I have a 1/2 mile lane).I've done the following:checked for vapor lock by removing gas cap. Still does itremoved air cleaner. still does itrebuilt fuel pump. still does itchecked fuel pressure. 12psichecked fuel pumped volume. normalPulled top off carbueretor. fuel bowl full (float is set right!), float dry, cleaned up interior of carburetor, blew through jets, etc. Still does itThe engine starts easily and idles smoothly, pulls fine on hills (except when 'acting up'). Nice hot blue spark.I'm completely baffled. Have any of you encountered a problem like this?Thanks in advance for all replies. Link to comment Share on other sites More sharing options...
c49er Posted October 20, 2012 Share Posted October 20, 2012 (edited) The Oilite disc filter in the tank possibly is plugging up after enough running time. Fuel pressure should be no more than 5 lbs.Is the flex hose at the fuel pump new and of modern rubber? Edited October 20, 2012 by c49er (see edit history) Link to comment Share on other sites More sharing options...
rls120 Posted October 20, 2012 Author Share Posted October 20, 2012 C49er: Much thanks for your reply. I'm not comfortable with the fuel pressure either, but can't quite figure out why too much would be a bad thing (unless the float bowl was overfilling, which it isn't).Can you tell me any more about the "Oilite disc filter"?The flex hose is NOT new, and a good suggestion that I hadn't considered. Duh! I'll be checking that out tomorrow.Again, I thank you. Link to comment Share on other sites More sharing options...
keiser31 Posted October 20, 2012 Share Posted October 20, 2012 I had a 1949 Dodge that did the same thing as yours. I found out after I sold the car that the coil heated up and shorted out. That was it. It may or may not be your car's malady, but you never know. Link to comment Share on other sites More sharing options...
StillOutThere Posted October 20, 2012 Share Posted October 20, 2012 I also vote for coil replacement. Had a Hudson of this era that the coil deteriorated to the same condition as yours while on a road trip. Pulled one from a junk yard car for $2 and drove 40 miles to the next parts house and got a new one. Drove 900 miles home. Link to comment Share on other sites More sharing options...
c49er Posted October 20, 2012 Share Posted October 20, 2012 I agree on the coil replacement. I thought I read it was already replaced. A common MoPar flathead issue. Link to comment Share on other sites More sharing options...
rls120 Posted October 20, 2012 Author Share Posted October 20, 2012 Thanks, guys for the coil suggestions. I had been considering that as a remote possibility, but, on hearing from three of you that its a common problem, I'll be swapping in a spare ('borrow' the one from my Farmall Cub for diagnostic purposes!). As soon as I've tried it, I'll post back and let you know. Link to comment Share on other sites More sharing options...
Rusty_OToole Posted October 21, 2012 Share Posted October 21, 2012 Fuel pressure is way too high. I don't know how you get 12 lbs out of a stock fuel pump. Did you use a different spring when you rebuilt it? If so put the softer one back in. Or, get a pressure regulator, mount it on the carb and set it to 2 PSI. Link to comment Share on other sites More sharing options...
rls120 Posted October 21, 2012 Author Share Posted October 21, 2012 Rusty: I'm not sure why the pressure is so high, but it could have to do with the check valves, which I did NOT mess with. The diaphram spring that came with the rebuild kit is the only one replaced. Link to comment Share on other sites More sharing options...
rls120 Posted October 21, 2012 Author Share Posted October 21, 2012 I swapped coils today and it made no difference, so tomorrow I'll be investigating c49s suggestions about fuel lines, etc. Link to comment Share on other sites More sharing options...
c49er Posted October 21, 2012 Share Posted October 21, 2012 (edited) Gawd, I'm hope I'm steering rls120 right!Bob Edited October 21, 2012 by c49er (see edit history) Link to comment Share on other sites More sharing options...
auburnseeker Posted October 21, 2012 Share Posted October 21, 2012 I would trace the fuel line from the pump to the tank and make sure someone didn't add an inline filter that is about plugged up. Just a guess. The rubber flex line at the pump is also an easy check as suggested. The inside may be coming apart and a piece of the rubber acting like a check valve. Alot of the flex lines were an outer and inner layer of rubber so the outside could look fine but the inside could be shot. You could mount some kind of small 1 gallon can or jug and bypass the line from the tank going directly to the fuel pump. That would tell you if the problem is before or after the pump. Good luck. Link to comment Share on other sites More sharing options...
rls120 Posted October 22, 2012 Author Share Posted October 22, 2012 (edited) Guys, I think I'm homing in on it. The hose looks 'modern', but I do plan to replace it. Today I blew through the entire line (from the fuel pump end) in hopes of clearing out the tank filter. Had the gas cap off (didn't want to pressurize the tank), and could hear the gas bubble. Took it for a drive, and it made it up my (very steep) hill three times. First time its ever not died on that hill. Then I took it to the gas station (about a mile away), then back home. Died on the hill. I'm thinking I need to read up on that filter, and see about removing or replacing it. The gas can idea is a great one, and I'll be trying it soon, just to make sure. It may be a few weeks before I post again, as I usually don't find time to work on my toy during the week, and I won't be home next weekend. I will post as soon as I find something out, and thanks to all of you for your help. Bob Edited October 22, 2012 by rls120 (see edit history) Link to comment Share on other sites More sharing options...
Ron42Dodge Posted October 22, 2012 Share Posted October 22, 2012 (edited) I've got a new thought. I had similar problems with my 42. Went down many of the same paths as you have. I believe I actually fixed it this year as this was the first summer I did not break down.The answer was, a broken wire on the distributor plate. The wire was broken inside the cloth wrap. It looked fine. It would make some contact to get me going but eventually would quit, usually under load. I would get towed home and then it would start right up again and I could drive it into the garage. I believe as the vacuum advance would move the plate which would move the wire. The wire would vary its end to end connection with the flexing.I found a NOS distributor plate with points and condensor and put it in over the winter. The car ran stronger, smoother and never failed.That is my suggestion.Ron Edited October 22, 2012 by Ron42Dodge (see edit history) Link to comment Share on other sites More sharing options...
c49er Posted October 22, 2012 Share Posted October 22, 2012 Yep, That breaker plate wire is an issue when they get old. You have to use a special very fine multi-strand wire too otherwise it won't last long because of the constant breaker plate movement.Bob Link to comment Share on other sites More sharing options...
rls120 Posted October 22, 2012 Author Share Posted October 22, 2012 Ron: nothing worse than an intermittent electrical glitch! I'm glad you found yours, and I hope I find mine, if thats what it is. Thanks for the idea, I'll check it out. Link to comment Share on other sites More sharing options...
Rusty_OToole Posted October 25, 2012 Share Posted October 25, 2012 Factory spec for your fuel pump is 3 to 4 1/2 pounds of pressure. Less than 3 pounds can starve the carburetor. More than 4 1/2 pounds can cause carburetor flooding. This information is from the factory repair manual for the 1950 Chrysler. The pressure is controlled by the spring behind the diaphragm. Suggest you replace the spring or add a pressure regulator. Link to comment Share on other sites More sharing options...
Ron42Dodge Posted October 26, 2012 Share Posted October 26, 2012 I looked in my shop manual and for 41-48 Dodges the fuel pump pressure range for those would be 3 1/2 to 5 1/2 pounds. The must have lowered the pressure for 1950. Same problems and same results. I believe if you really have 12 lbs of fuel pressure, you would have fuel flowing out the bottom of the carb all over the exhaust manifold. You may want to recheck the fuel pressure or possibly the gage. Link to comment Share on other sites More sharing options...
Rusty_OToole Posted October 26, 2012 Share Posted October 26, 2012 Either way 12 PSI is way too much. The best answer might be to put a pressure regulator at the carb and set it to 2 PSI. Link to comment Share on other sites More sharing options...
Guest John1918 Posted October 29, 2012 Share Posted October 29, 2012 I haven't read through all the replies yet to see if it has been mentioned yet but what about checking the fuel cap to see if it has a vent? It's possible to have a vacuum build-up in the tank fighting against the fuel pump and perhaps even sucking air into the fuel line. Link to comment Share on other sites More sharing options...
rls120 Posted November 17, 2012 Author Share Posted November 17, 2012 Sorry its taken me so long to get back, but I just today got a chance to do some more investigating and ITS FIXED!It was evidently a collapsed/blocked/compromised section of fuel pipe. I was messing with same, trying to determine if I was getting enough fuel out of the tank (thought maybe the in-tank filter was plugged). Determined that there was not a problem there, and strained the (rusty old) pipe at a fitting on the frame. I spliced a new hose around that bad spot, and, just for grins, took the car for a drive. Ran great, up and down my hill numerous times. Went to the gas station, and it ran great. Went for a 10 mile drive: no problems. The transmission shifts like its supposed to, and the old girl runs straight and true down the road very nicely. We got the heater working too!Thanks for all of your advice: I'm happy to have my new toy finally running like its supposed to. I'm sure I'll be back with more questions as I continue working on her. Link to comment Share on other sites More sharing options...
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