Hard Start after Warm looking for suggestions

[ford1]

im not sure if the earlier ford v/8 intake manifolds had the heat cross over passage , if it does plug them with real copper pennies in the block under the manifold, not the new pennies, will keep the carb from being heated by exhaust gas, put in a 1/2" carb spacer under carb to keep it away from the manifold and it will help keep it cooler

[OldDad]

Yes, good advice Ford1, I will try this on mine before the weather heats up again. Have one inch spacers on an Evans 2x2 with 97's, but the spacers are aluminum, and conduct the heat beautifully!

[hotrod8]

had a 46 mercury did this when i was a teenager, whn warm i could push it ten feet ,pop the clotch and it started , valves were burnt up !!!!!!!!!!

[G.M.]

hotrod8 Why did you have to push it 10 feet? I suspect the battery was low and wouldn't turn it over with enough power to start. Plus a weak battery running the starter pulls the voltage to the coil down so low there is not enough spark to fire. Pushing the car is no differant then the starter turning the engine over EXCEPT the starter isn't pulling the voltage down and even a weak battery will start the car if it rolls 10 feet. G.M.

[DICK SPADARO]

I have the same issue with my flathead on hotter days 80-85+. Engine starts on 1/2 roll of the starter everytime when cool. Take it for a moderate drive and get everything heated up, stop and set for 2-5 minutes, starts difficult. Most suggestions are ignition related and are valid topics but I have fiddled with this issue all summer and I feel that if your engine fires easily its not an ignition problem.

Again I have addressed the fuel as the suspect of hard starting. This eco friendly new ethanol fuel is not old car friendly. The ethanol additive makes the fuel vaporize too easily and it is my opinion that the fuel is evaporating out of the hot carb, lowering the accellerator pump fuel level and making the car hard to start. If you crank the engine over a couple times to get the fuel bowl refilled then the vehicle starts. This take 4-5 complete spins of the engine and grinds down the battery and taxes the starter.

You can check this buy operating your vehicle up to temp on a hot day, stopping and letting the engine heat soak for 5 minutes or so, then squirt some starting fluid in the carb. Attempt to start the engine, if it fires rightup you can eliminate any ignition problems and the fuel system is suspect. It is also important to have a good fuel pump diaphram not over 2 years old, the diaphram stretches out when setting idle and the efficiency drops excessively as they age. It is a good idea to replace the fuel pump diaphram every spring if you are using ethanol fuels.

To help eliminate the evaporation issue I have raised the float level in the carbs so they contain extra fuel and make the evaportation process slower when the carb and engine is hot. This seemed to help remedy the issue but not totally eliminated the hard start on super hot days.

My sugggestion would be to first check the condition of your fuel pump, diaphram and then reset your float level to a position higher than normal to retain more fuel in the fuel bowl to overcome the evaporation issue.

[G.M.]

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Dick as you know I never believed in vapor lock and couldn't make it 6 or 8 years ago on a HOT 38 ford on a 95 degree day. A friend had had problems after resetting the points 3 or 4 time after driving 25 miles. The problem turned out to be someone put extra springs under the point springs and would wear the shoe riding on the cam. He came by with it and I heated the carb, fuel pump and fuel line until the gas in the pump filter bowl was boiling. Could turn it off wait a few minutes and it would start right up. He left the car and in about 20 minites I had a small red rash all over my hands and arms, 20 minutes later the rash turned to burn blisters from just bumping anything on the engine. This summer I drove my 39 to Pa. and drove it every day up there. On 2 or 3 mid 90 days I stopped for maybe 10 minutes. It didn't start on the first turn, maybe the third or forth and I started out and in a 100 or 200 yards it gave a few chugs like a gas problem. One time after 200 or 300 yards it it died and still coasting I let the clutch out and it caught, struggled a few times and was OK. Driving back to Florida my battery went bad 800 miles from home, not enough power to crank start, had to kick start or use the battery pack. Just above Tampa I stopped for gas, the station was filled and I stalled the engine, got the battery pack, started it and turned the Idle screw up 2 turns. Waited and got to a pump and left the engine running while filling the tank. It was in the low 90s and I pulled out of the station, turned right to make a U turn to get back on I-95 and it stumbled and died. I coasted to the middle lane which was marked off for no traffic. I got out and opened the hood and before it was up a young sheriff puled up behind and asked if he could help and I said I didn't think so I would get it running. Got the battery pack and cranked it to the starter with 12 volts and no go. I have a 4 lb pressure gauge in the fuel line between pump and carb. I cranked it and asked the sheriff what the gauge said and he said almost 1 lb. I could see bubbles in the filter bowl. I have the gauge on testing a pump diaphram and thought maybe the test wasn't turning out so good and would have to change pumps. I gave it a few shots of either and got it running with a squirt of either once in a while to keep it running and the pressure came up to 2 lbs. It had been running at 3+ and thought the diaphram was streatched a little but I only had 125 miles to go. It kept running and I made a left througt the red light and the cop looked away. It started acting up and I had to decide do I want to change the pump on I-75 or here. I turned right on a small side road and went 300 yards and it started clearing up so I turned around and got on I-75 and it ran perfect all the way home. Next day I put in another Optima and it started on the first turn and had a little over 3 lbs pump pressure. The tank was down to 2 1/2 gallons before getting gas and with the heat from the dual exhaust pipes, hot road and engine heat comming back I wouldn't be surprised if the gas in the tank wasn't boiling and after filling the tank and took a while to cool. I don't think it took much over 5 minutes to get started when it quit so it was still hot. Please don't tell anyone I mentioned VL. G.M.

[OldDad]

For what it's worth (probably not much), here's what I've determined with my hot start problem. Starts right up cold, but cranks over repeatedly hot (after sitting a few minutes) and will usually start if I hold the throttle on the floor (flood treatment). But sometimes on a hot day, no start at all, unless, as Dick suggests, I hit it with ether, and then it will start right up. I found if I parked it in the garage when hot, I could smell gas quite strongly, and one day noticed some fuel dripping from the throttle shaft of the front carburetor. I attributed this to percolation out of the float bowl, but it could be from another source. I had set the float level cold, so I checked it again when thoroughly hot, and found no difference. Lowered it a bit, but this made no difference in the hot start/fuel odor problem. If I turn off the electric pump (no mechanical pump) and allow it to run until the bowls are lowered or empty, it will start up hot, after of course allowing the bowls to fill before cranking. So, I speculate that you could end up with both lowered/empty float bowl and a flooded engine due to percolation at the same time. As Dick said, try the ether to take the ignition out of the equation. A frustrating problem which makes it difficult to use the car at all on hot days. And a long trip in the summer . . .

[BOSSY]

Some thing to look at. I had a 48 Mercury that would start right up cold but when it got warm would bearly crank over. What I found was a bad starter solenoid, it would have a very hot terminal on it. When I changed it ,it started like new again.