Hard starting 53 flatty when hot

J

j_macy

Member
here is the situation I have a 1954 Meteor Sunliner (Canadian car) with the mercury flathead engine. Car and drives like a charm.
I have changed the rad and have 160 thermostats and the running temp is around 170-180. I have also rebuilt the holley 2bbl carb with a kit from macs. Also have went to the pertronix ignition instead of points. still 6 volt system.

the car if started every few days starts fine if it is allowed to sit for a couple of weeks I have to prime the carb with a little jug of gas. Also if you take it for a drive up to operation temperature and stop, shut the car off it will fire right up. Allow it to sit for ten-twenty minutes and then it's very hard to start. I am thinking that some thing is not holding in the carb and is allowing fuel to seep into the intake flooding the engine
 
J_Macy wrote: >>>pertronix ignition instead of points. still 6 volt system.>>>
19Fordy wrote:>>>change the condensor and see what happens.>>>

Does a petronix ignition use an external condenser?

Jack E/NJ
 
j_macy wrote:>>>I am thinking that some thing is not holding in the carb and is allowing fuel to seep into the intake flooding the engine>>>

Sounds reasonable. Have you tried blocking the intake manifold's exhaust heating holes to see if it might be a gas boiling issue?

Jack E/NJ
 
Not vapor lock, assuming there is such a thing. I'm thinking more like percolating the gas out of the bowl, down the chute, and flooding the engine. Be interesting to peer down the carb's throat for a few minutes after a hard run to see what's percolating. 8^)

Jack E/NJ
 
I know your power valve is new but it could be leaking around the p/v gasket or the three bolt base gasket where the p/v goes, due to warpage. these two things are very common problem.
 
j_macy said:
here is the situation I have a 1954 Meteor Sunliner (Canadian car) with the mercury flathead engine. Car and drives like a charm.
I have changed the rad and have 160 thermostats and the running temp is around 170-180. I have also rebuilt the holley 2bbl carb with a kit from macs. Also have went to the pertronix ignition instead of points. still 6 volt system.

the car if started every few days starts fine if it is allowed to sit for a couple of weeks I have to prime the carb with a little jug of gas. Also if you take it for a drive up to operation temperature and stop, shut the car off it will fire right up. Allow it to sit for ten-twenty minutes and then it's very hard to start. I am thinking that some thing is not holding in the carb and is allowing fuel to seep into the intake flooding the engine
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This would not be the power valve. If it was leaking that bad, you would be able to screw in the mixture screws and it would keep idling along.
 
I have posted this before and I dont want to sound like a record skipping but the situation is caused by the new ethanol based fuel. The evaporation point of this fuel is lower than gasoline and if your vehicle sets for a period of time the fuel evaporates to a low point in the float bowl and requires you to prime the carb with starting fluid or a shot of gas to get it started.

The same holds true for hard hot weather starts, if your hot engine sets for a short period of time the fuel evaporates out of the carb due to the heat sink temperature and the vehicle is hard to start.

I have not completly been able to cure the non use hard start issue with my own vehicles but by increasing the float level to maintain a higher level of fuel in the float bowl has some what cured the hot start issue. There is nothing wrong with the igntion sysytem it is the gas.
 
j_macy said:
here is the situation I have a 1954 Meteor Sunliner (Canadian car) with the mercury flathead engine. Car and drives like a charm.
I have changed the rad and have 160 thermostats and the running temp is around 170-180. I have also rebuilt the holley 2bbl carb with a kit from macs. Also have went to the pertronix ignition instead of points. still 6 volt system.

the car if started every few days starts fine if it is allowed to sit for a couple of weeks I have to prime the carb with a little jug of gas. Also if you take it for a drive up to operation temperature and stop, shut the car off it will fire right up. Allow it to sit for ten-twenty minutes and then it's very hard to start. I am thinking that some thing is not holding in the carb and is allowing fuel to seep into the intake flooding the engine
Click to expand...
In the first place you bought the cheapest and about the worst kit on the market [i know what they sell] Course from China. Garenteed it had the wrong power valve in it 7.5 # and gasket/ a rubber accelerator pump[garbage] and a rubber tipped inlet needle [also garbage] You get what you paid for.Buy a U.S.A. made kit and end your problems. Kens Ford Carburators. ken ct. Or have it rebuilt by someone who knows what hes doing and uses correct parts .:)
 
Another cure for the manifold heat sink evaporization of the fuel is to put a double gasket between the carb and the manifold. That adds insullation between the two. It helps. Some cars already come with a phenolic spacer between the manifold and the carb to give you that insullation of heat from the manifold.
 
I vote for the power valve. Dealt with this many times, one cough through the carb while starting can ruin the power valve and all your fun at the same time. Have had a pair of vintage speed rebuilt Stromberg 97's (no power valve) on my Merc-powered '32 fror 6 or 7 years now. The most trouble-free carburation I have ever had on a flatmotor since my first back in '62. I'll bet if you pulled the plugs when the motor is hot and won't start they'll all be wet.
 
This is a very common problem and as Dick said the fuel percolates in to the manifold. When you try to start it, you have an excessively rich mixture. Try starting it by cranking with the pedal to the floor. Worth a try. And anyting you can do to insulate the carb from the hot engine will be a plus.
 
Here is an entirely different approach.We had a very similar situation with a Packard.The car was a bit over restored.The starter was painted when rebuilt and so was the mating surface (starter housing).We removed the starter,wire-brushed the paint off both surfaces,ran the grounding cable to one starter bolt, and presto! A Packard that will start when hot. James
 
1: Take a loose sparkplug, connect to a sparkplugwire and ground the spakplug. Have someone turn the engine over when you have starting problems. The spark must be Blue, anything else you have an igintion problem

2:If the ignition is OK, remove the aircleaner, turn the throttle looking for gas squirting from the acceleratorpump. If no . If its empty the fuelpump should fill the carb after some turnover of the startmotor. So check the Fuel line between the pump and the gastank, any airleak/leeak there will let the fuel drainback to the tank.
And the pump will have big problem's sucking it back (thats the reason for the need to prime the carb). If ouy are at home you can remove the line between the pump and carb and take a can to catch fuel in. and let someone turnover the engine, you should get a fule pumping for each engine revolution
 
Most if not all new FP.s are coming in from China.Diafram spring they put in is too strong causing excess fuel pressure. Diaf are also made of questionable material.Have your old pump rebuilt in the states.Also the valves they use arn't the greatest either.ken ct/
 
flatjack9 said:
This is a very common problem and as Dick said the fuel percolates in to the manifold. When you try to start it, you have an excessively rich mixture. Try starting it by cranking with the pedal to the floor. Worth a try. And anyting you can do to insulate the carb from the hot engine will be a plus.
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I have the same problem with dual 94s on my '51, this after spending much time over the years and several tear downs making sure the power valves and steel inlets (now from ken ct) were not leaking and floats set correctly, etc. I agree with Dick and flatjack, it's the fuel. We have a minimum of 5% corn gas in this area on top of the "other" stuff in modern gasoline. I also use the "pedal to the floor" method when the engine is fully warm after short 5-10 minute or so shut downs, and installed an inline 6V pump to prime the carbs after a week or so layup.

One thing I have noticed is I do NOT have the same hot start engine problem with the triple 97s on my '32. (Full time electric pump eliminates any cold start issues) One of these days I'm going to switch the 94s to dual 97s on the '51 and see if the hot start problem persists.
 
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