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Need some help - 1934 Dodge DR Sedan starting problem


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Hi all - having a problem that I can't figure out and hoping someone has an idea how to fix it. I have a 34 Dodge DR Sedan that will only start without a blast of starter fluid. Cold or warm; choked or not, it will not start under any circumstances unless I give it a quick squirt of starter fluid, and then it starts right up. I have even tried 100 octane gas with and without lead substitute. Any ideas?

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Thanks,

Dave

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I have been messing with my car for a while now with very similar troubles. I did seem to find that the carb bowl dries out very quickly. I think it has something to do with the gas volatility now-a-days. The carb seems to run dry very quickly after turning off the engine from the heat coming up from the exhaust manifold. I have been giving this idea a line of thought recently. What do you think?

I do not think the 100 octane gas would help - it may even cause more trouble with volatility. Lead additive really has nothing to do with this. BTW: Aren't the valve seats on the '34 hardened like on the '36? There would be no need for extra lead unless pulling a trailer under load, driving at high speeds consistently, or driving in high heat (desert) a lot. I was even kicking around the idea of adding a bit of kerosene to the fill in an effort to change the fuel volatility. (But I don't think that would help much.)

Edited by 1936 D2
more data (see edit history)
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Before you try to start it take off the air cleaner and remove the top of the carb float. It's not too difficult. Your Carter/B+B carb top should come off with 4,sometimes 5,screws. The top of the carb will just lift off with the choke and it's cable still attached. There are no 'guts' in the top of the carb. The float chamber should be full,or nearly full,of gas. If not the problem is the fuel pump unless the needle valve for the float is partially stuck closed. The rubber tip does tend to rot after a while. Look at the fuel sediment bowl at the fuel pump. Is it full? I once had a similiar problem caused by the sediment bowl cork gasket drying out and shrinking and allowing the pump to suck air. The bowl would never fill up and the carb float bowl was never full either. Caused rough running and hard starting.

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When I have taken the top off the carb before, the bowl was empty and DRY. The fuel sediment bowl on the pump was full. Pretty sure it is not a fuel pump issue because it runs fine once started.

And actually just giving it a blast of starter fluid causes it to run long enough to get fuel into the bowl which then sustains it.

I am guessing that Dave's '34 problem is pretty much the same. Correct me if I am wrong please.

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I tend to agree with KLC. I have had this happen before and it was the needle valve seating. Interestingly, if the carb relied on gravity feed, the opposite would happen and the float chamber would flood. My guess is that the cause is ethanol in the petrol. Can you still get service kits for your carb? If not, a carb specialist will probably help.

Ray

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Thanks all. I will try KLC's suggestion and look at the carb as soon as I get some free time. I should have mentioned that the carb was rebuilt 6+ years ago, but the car's only been driven about 200 miles since. Also the car is converted to 12V and has an electric fuel pump. Wouldn't that keep the bowl full?

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If anything, you would more likely have too much pressure with an electric fuel pump but the simple answer is no, it makes no difference and cars run perfectly well on either 6 or 12 volts.

Pretty sure it's the carb. You have checked for leaks I take it?

Edited by R.White (see edit history)
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Dave,

With an electric pump you should be able to fill the carb float bowl by just turning on the pump. This assumes you have no mechanical pump, or the mechanical pump is disabled so as to let gas flow through from the electric pump, or you have an electric pump designed as a priming pump to work in unison with a mechanical pump.

If the pump(s) are capable of delivering fuel to the carb, then there is a carb needle / seat problem if the bowl is dry.

There are a lot of variables with an altered fuel delivery system. We would need to have the details of your current setup to accurately give other suggestions.

If the bowl isn't dry then there could be some sort of timing issue causing hard starts or some kind of rather large vacuum leak that is off balancing the carb.

These ideas and anything else would be guesses without knowing more info from diagnostic tests.

Toss us a bone as you get more info.

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Well, you really have me scratching my head on this one. Not owning a car like yours at this time, I can only speculate. I don't think it is the volatility of your fuel at all, having a no or low level of fuel in carb bowl. A few ounces of pure alcohol or pure gasoline in that carb bowl will not completely evaporate in a few days. Where would it go to? The throttle plate being closed, No way can the fuel evaporate out through the tiny vent hole. There HAS to be a leak, somewhere. If you say only a shot of starting fluid gets it going, Ok,--- that will not "un-stick" a faulty float valve, so I will count that problem out. The fuel must be leaking out through either a bad gasket under one of your carb jets, or a loose jet. Or of course, a cracked carb, but that would be quite obvious. Keep in mind, the carb float and the up-stream components have to be verified OK., like the fuel pump and it's internal check valves, pump diaphragm and the pump's push rod. Even the fuel line from pump to carb must be checked for tightness of the fittings and good shape, in the original configuration! I've seen problems arise with people varying from factory spec's and incorporating a loop in the line, now causing an air blockage with certain conditions.

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I think we are all scratching our heads on this one. My theory, for what it's worth, is that the problem is typical of what happens when the original system is adulterated instead of being repaired or serviced. As 1936D2 said, if the fuel pump is capable of delivering gas to the carb and the float chamber remains dry there must be a problem with the needle valve sticking shut and preventing it from filling the bowl. But where has the last charge of fuel gone? This is the strange bit. A poor seating allows the carb to flood.... KCL referred to a rubber tip which can perish but I am unfamiliar with this however, I would imagine it would cause flooding rather than starvation. Perhaps the pump looses it's pressure when left standing and allows the fuel to go back down the pipe and back fill the pump and sediment bowl.

I would go back to the original set up. Each to their own. The original system relied upon air pressure and gravity - with vacuum assistance.

If on the other hand, the pump is not providing quite enough fuel to the carb then this will manifest itself in rough running as fuel starvation causes misfiring and weak mixture. Left unattended this can cause burned exhaust valves resulting in low compression.

Chances are that there is a leak somewhere. My motto is "it's probably something simple" - (although this only applies to the pre - electronic age.) Just a few thoughts thrown into the mix.

Ray

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Here are some more pic's of the car. I will take & post pics of the carb & fuel lines this weekend.

As far as suggestions of a leak - none are visible, plus the inability to start w/ gas alone is constant. Even if the engine has been running for a while, then is shut off and immediately tried to be restarted, it won't - unless starter fluid is used.

Thanks, Dave

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Here are some more pic's of the car. I will take & post pics of the carb & fuel lines this weekend.

As far as suggestions of a leak - none are visible, plus the inability to start w/ gas alone is constant. Even if the engine has been running for a while, then is shut off and immediately tried to be restarted, it won't - unless starter fluid is used.

Thanks, Dave

Nice looking car!

Shut off and then will not restart immediately without starter fluid. And when you check the carburetor float bowl it's empty? That is a bit of a puzzle.

By the way if you are in Willow Glen then I'm probably only about 10 miles from you. My '33 Plymouth probably has a very similar fuel delivery system (mine is stock). Let me know if I can be of assistance with on site diagnosis. I'm no expert but some times two sets of eyes will catch something missed by one set.

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Bill, I was thinking about that too, but if the fuel line at carb is dumping gas into bowl at a higher level than the float allows it to go, the fuel cannot siphon or run back out through fuel line when sitting or any other time. That's even if the fuel could get back through the float valve! I still hold in my opinion that the bowl is leaking is IN the carb, at the base of one of the jets. Either a loose or cracked jet or a bad gasket under one of the jets. The bowl would empty under gravity, given a short time, into the manifold where it goes unseen.---Pete.

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That certainly sounds like a distinct possibility, Pete. I am still trying to figure out why the gas could not return down the fuel line just enough to empty the bowl if the valve was not seating; that is assuming it is a bottom entry carb. The reason I thought this was because originally the needle valve would have been under atmospheric pressure (about 15lb psi) even when not in operation. The introduction of an electric fuel pump would mean pressure only when switched on - although residual pressure would exist but may be lost in a worn pump. If the carb is not a bottom fed type then your hypothesis would be correct as there would be nowhere else for the fuel to go.

Ray

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Yup, I agree Ray, We won't be able to go any farther until we get to see the carb and his set-up with lines and his pump(s). I think he's got a top feed carb, but who really knows as yet. As you must know, it's extremely difficult to cure a problem with just photo's. An owner must start with the basics, such as known good vacuum, gaskets, clean fresh fuel and tank also. When I hear that the stock design has been circumvented, I cringe at the thought of troubleshooting a problem "over the airways". I'm thinking that someone before him added the electric fuel pump, Why? Did the diaphragm fail in the mechanical pump? If it's an A.C> Delco pump, can it be possible for the gas to drain down, past a faulty check valve inside that pump, and dumping fuel into body of pump, whereas fuel would then drain into his crankcase.

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Say, Pete. What if someone has left out the gasket under the jet on a rebuild? Would that do it? I like this sort of puzzle - it gives me a chance to exercise the few little grey cells Iv'e got left! (chuckle).

Ray.

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If it's a top fed carb and the float chamber is found to be empty, I think there must be a leak because there is nowhere else for the gas to go. It's not likely, in my view, to have evaporated. If the fuel has leaked away there is no mixture to ignite. It won't fire up, so that's what the starter fluid is replacing. I would think that fuel having found it's way to the inlet manifold will get burned off, producing black smoke. Gas will be supplied to the carb as soon as the pump starts working which is when the ignition is switched on. Once the engine is drawing fuel through the carb it must be coming from the float chamber. What I can't understand is why the pump takes so long to replenish the float chamber?

Ray

Edited by R.White
me talking codswallop (see edit history)
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A slow leak from the jet will not necessarily flood the engine upon starting. Especially a hot engine whereas the leaking gas evaporates faster than any noticeable clue.One needs to remember, the float is there to set a level in the bowl, that is almost equal to the top opening of the jet! The starter turning the engine creates enough vacuum in the venturi for that instant to atomize the fuel and air,(faster with choke plate closed, of course), for the proper charge of mixture for the cylinders. If the bowl level is too low because of a leak, that initial vacuum won't pull the gas out of the jet, whereas the ether initiates starting and enough vacuum is created to get the bowl/jet to proper level. NOW---Is this clear as MUD??? The 1/2 to 1 ounce of leaked fuel in the manifold is just gunna sit there and evaporate a bit, not enough to vaporize with any air for starting this creature.

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I agree, if everyone knew everything there would be little point just preaching to the converted so to speak.

O.K. so it looks like there is a leak. I once had a similar problem. Everything looked O.K. until my Dad found a loose jet. It practically fell out! When the jet was tightened up, the fuel consumption returned to normal. The difference here is that the electric pump seems incapable of filling the float chamber. With the ignition switched on it should quickly replenish the bowl to the level needed for the vacuum to draw it through the jet. I guess the leak must be a bad one or insufficient time is being given for the pump to do it's job. You should be able to hear it stop clicking when the needle valve cuts it off. If the pump continues to click, either the valve is not seating properly, there is a leak, or there is a fault with the pump. We have established it is the wrong pump.

How does that sound? Gibberish I expect.

Ray.

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Yes Ray, What you described with your Dad's carb is happening more frequently than people think. Some carburetors originally used gaskets under some, or all, or none of the jets. The gaskets were of the pressed paper type, usually red in color, which have a tendency to dry out and even fail after many, many years of doing their job. Some rebuild kits for older carb's are now using replacement gaskets made of a Teflon material, which won't dry out and shrink, but one can still have a problem with those type if they over-tighten them, they have a tendency to mushroom out and deform, causing a leaky situation. There's a very fine line on tightening down a jet properly. As you know, the little brass jets are hollow, and folks seem to forget this and over-tighten them, causing a crack immediately or breaking them right off! Many jets used a "interference fit", meaning the threads of the jet were special threads that when mated into it's opening, sealed in tightly, automatically, so no lock washers were needed. Sometimes no gasket either. One needs to know their carburetor. Getting back to the story here, If his electric fuel pump is most likely down-stream of the mechanical one, that electric pump may be doing it's job OK, supplying fuel up to the old pump and that's where it stops. There are small check valves in the mechanical pump that won't let the fuel by-pass to his carb until the old pump actuates. He should by-pass the old pump completely.

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Hi All! Again my thanks for your ideas and inputs. Here are a few pics of the carb & feed line:

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The carb is side feed as can be seen. The feed line goes to the side of the engine & then downwards to an inline filter. From there it goes to the underside of the car and back to an electric fuel pump located about midway on the car and from there to the gas tank. The original fuel pump is not connected to the line. I do not know why it was bypassed and an electric pumped installed. It was put in by the previous owner.

The electric fuel pump is turned on when the key is turned to the "on" position.

I have not yet opened the bowl on the carb, so I do not know if it empties when the fuel pump or running engine is turned off. I will try to do so soon.

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Nice looking car!

Shut off and then will not restart immediately without starter fluid. And when you check the carburetor float bowl it's empty? That is a bit of a puzzle.

By the way if you are in Willow Glen then I'm probably only about 10 miles from you. My '33 Plymouth probably has a very similar fuel delivery system (mine is stock). Let me know if I can be of assistance with on site diagnosis. I'm no expert but some times two sets of eyes will catch something missed by one set.

Ply33 - yes I would very much appreciate some assistance! I'm lost my right leg 2 years ago and can stand on my prosthetic leg for only a short amount of time, so am mostly in a wheelchair, which limits the amount of things work I can do and makes actually driving the car impossible. My daughter's boyfriend helps me when they visit, but he doesn't know much about old cars. I have not checked the float bowl yet so I don't know whether it's empty or full. It being empty has been suggested as one cause of the starting problem but, as I said, I have not yet confirmed that. If you can stop by, that would be great. Call me at 408-265-4842 or email me at dbenzing@ix.netcom.com. I am home almost all of the time.

Thanks, Dave

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Wow Dave. I think you found a good "car buddy" there! Excellent!

It then seems as though the fuel is pulled from the tank by the electric pump and pushed up through the inline filter to the carb. A much simpler flow than what we all were envisioning concerning having the old mechanical pump in the line yet.

So, I will put my 2 cents worth in (maybe 5 cents) right here then stand back and watch! (That's the cool part!) Anyway, starting at the tank. You need to have an actively venting tank for this pump system to work. So you need to check the cap to make sure it can vent air into the tank. If it is not, you may even see some big "dents" in the tank if the pump can pull hard enough and it sucks the sides of the tank in. Venting is important for full fuel flow.

Next, you need to make sure the lines and fittings from the tank to the pump are tight and not leaking air into the line when the pump is running. If air is getting in along that line, the pump will not work well because it can't pump air, only liquids.

I do not suspect the lines are leaking from the pump to the carb because you would see and smell that. You may even have experienced a fire if it was! So, just to be on the safe side, inspect the lines to make sure all is well both before and after the pump.

You may want to change the inline filter just to be sure it is not blocked up. It is a metal one so you can't see what the flow rate is through it. Maybe consider replacing it with a clear one. If you do, you probably will see air in the filter at some times. This seems not to be a problem as we have discussed this issue of air in inline filters on other older posts.

Then the carb is next. It is a matter of seeing that the needle at the seat in the filler fitting is capable of doing its job properly. That means it needs to close off the inbound gas when the bowl is at the correct fill height, and to open fully when the level is low in the float bowl. Both things are important. Depending on the construction inside the carb, the needle may need to have a small spring type "hook" around it and to the float arm to sufficiently pull the needle off the seat. Then the float arm has a metal tab that pushes the needle back tight into the seat to stop the flow. All this has to work smoothly and as engineered.

Sometimes with an electric pump the fuel pressure at this needle seat is way too high and the bowl will over fill and leak. But if you have a fuel pump made for these older 6 volt cars it MAY be correctly setup to deliver about 1 to 2 psi or so. If it is delivering the more usual 5 to 8 psi or more, you are waiting for bad things to happen because of an over filled fuel bowl. An inline pressure regulator would then be necessary.

If you look at the black cover on the carb you will see a dome on the top with a hole. That is the fuel bowl vent. It lets air move in and out of the bowl to assist with keeping the fuel level at the right location. That is also the hole I was speculating that the fuel evaporates from and empties the bowl. If the fuels are more highly volatile than the older fuels (read 70 year old fuel mixes), then I am postulating that the heat that can build up in the carb from the manifolds MAY be enough to quickly evaporate the fuel from the float bowl through this vent. That would leave the bowl empty for the next start. You would have to then run the electric pump for a bit, say until it stops clicking, BEFORE you try to engage the starter. That way the fuel bowl will be up to the correct fill level when the car is started. From then on it is up to the heat riser, choke, and strong spark to ignite the gas mix at the right time to run the engine. (Those things would need to be checked also).

If there is a fault with the needle and seat or with the float jamming up inside the bowl, the fuel may not enter the bowl enough to fill and there would be a hard start problem.

So it will be important to look in the bowl, see that there is fuel in there, at the correct level and that the needle and seat look OK, and that the float is in the correct position and not stuck on something or has a hole in it allowing it to sink. Also, while in there, check to see that the metering jet is correctly seated and has a good gasket if specified. That is about the only place the gas could "leak" out of the bowl without being seen I think.

And last but not least, make sure there is a "thermal block spacer gasket" somewhere in the lower connections of the carb to the manifold. That will be a thick, maybe hard plastic sort of looking piece, that is there to isolate the carb body from the manifold to prevent convective heat from getting to the carb body. Then all you have to watch out for is radiant heat. There are two spots where they were concerned about this. One is the heat shield used by the mechanical fuel pump to keep radiated heat from the block and exhaust manifold off the mechanical fuel pump and the gas lines in that area. The other is proper routing of the fuel supply line to the carb so it is not getting "cooked" from heat rising from the exhaust manifold.

Whew! That's about all I can think of. Hope "ply33" can help you out checking all this. Maybe your daughter and boyfriend can be around while you guys go through all this and pick up some pointers!

Have a great one!

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Ply33 - yes I would very much appreciate some assistance! I'm lost my right leg 2 years ago and can stand on my prosthetic leg for only a short amount of time, so am mostly in a wheelchair, which limits the amount of things work I can do and makes actually driving the car impossible. My daughter's boyfriend helps me when they visit, but he doesn't know much about old cars. I have not checked the float bowl yet so I don't know whether it's empty or full. It being empty has been suggested as one cause of the starting problem but, as I said, I have not yet confirmed that. If you can stop by, that would be great. Call me at 408-265-4842 or email me at dbenzing@ix.netcom.com. I am home almost all of the time.

Thanks, Dave

At present it looks like I can carve out some time next Saturday. You have a real puzzler here and I might not be able to help much. But maybe two eyes (and suggestions from everyone here) will lead to something. I'll give a call later in the week to tie down a time.

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Hi all. The problem was solved by replacing the fuel filter! I am a bit embarrassed by the simple solution and that I had not replaced it before asking you all for help. Because the car ran fine after starting, I never suspected the filter as the cause of the starting problem. I installed a new, clear one at 1936 D2's suggestion in order to be able to observe the gas flow, and it turned out to be the only thing needed as the engine starts easily now on its own. I still don't fully understand how a the "bad" filter only seemed to impact starting the engine.

Thanks to all for your inputs and a special thanks to Ply33 for coming by!

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I am glad you found the cause of the problem. No way should you feel embarrassed by it. I say very well done to 1936D2 for suggesting the fuel filter. It is easy to be right with hindsight and although we would probably all have come to the same conclusion eventually, it was our artful friend with the clearest head on the day who came up with the answer.

I think this admirably demonstrates the benefit of this forum - I for one have learned a lesson I will probably never forget and it fits in well with that moto I mentioned - "it's probably something simple"!.

I believe it was Pete who suggested you get someone to investigate the condition of your tank - I expect it needs cleaning out and perhaps sealing.

All the best,

Ray.

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  • 6 years later...

I have had problem with my 36 D2 carb fuel bowl not refilling.  Rebuilt fuel bowl now carb is out for rebuild.  Squirt gas in fuel bowl runs good for about 10 minutes then stalls.  Open carb no fuel in bowl.  Still happened after fuel pump re build (at Then and Now Auto looked great)  Hoping it is a bad needle valve tried cleaning it numerous times and ways needle l"looks" OK.  Carb should be back this week, we will see.

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Not pumping fuel?

Filters

Fuel pump

restriction in a line somewhere

(fuel pick up in tank)?

Fairly easy to eliminate some of these things especially of you have access to a portable boat tank.

Throwing parts may eventually hit but process of elimination may save you some money.

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Is there fuel in the glass bowl on the fuel pump?

 

If not, if you loosen the stirrup holding it on, does the bowl rock perpendicular to the stirrup? This results from over-tightening the stirrup. The top is bent.

 

That is able to be straightened. I can tell you the method if you need it, but remember pot metal is brittle so don't just attempt to bend it.

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