Fussy hot start

[Watermelon Jack]

I have a 65 Bird with a 390 that starts fine from cold. 2 pumps of the pedal and away she goes. Once it warms up and driven, when it is shut off and try to restart a short time later, it acts like it is starving. I am afraid to give it gas so it does not flood. Fuel seems to be the answer, does it evaporate off when parked hot? It has a new fuel pump and filter. Other than that, she backfires once in a while for no reason. It did pass the local air inspection recently.

Thanks, Jack

[Terry64HT]

Do you still have the spacer between the manifold and the carb?

[sseebart]

Sounds a lot like the heat soak/vapor lock issue I've been dealing with on my car. If you're running a non-stock air cleaner, you might try a 1" phenolic spacer between the carb and the water jacket plate. Also, check to see if your fuel line is close to or resting on the manifold or block. If so, try to isolate it.

I'm still working on this issue with my car, especially after longer drives; I would love to hear if you find a solution.

~Steve

[Watermelon Jack]

Thanks, I still have the spacer under the carb. It has 2 ports, the second one was wide open which I just plugged. This is the second car I have had this happen to, the port becomes uncovered without one knowing. Will do some driving today, it runs way much better. It still seems to fight trying to restart from hot when shut off for only about 1/2 hr or more. Will try to move the full line away from the intake, it is not touching, but way too close.

[Yadkin]

I converted mine to a throttle body EFI and it still likes a rich fuel mixture to restart at the condition that you describe. So I believe this to be inherent with this engine to at least some extent.

The backfiring indicates a timing issue. Consider advancing your initial ignition timing from the 6 degrees recommended five decades ago to 8, 10 or more- as high as you can go without knocking under load. Modern fuels burn slower so they need to be ignited sooner.

Your vacuum advance should also be connected directly to intake vacuum to advance, to add in another 12 to 15 degrees at idle. That way you get, say, 10 degrees BTDC to make starting easier then a total of 22 to 25 at 650 RPM.

[sseebart]

Originally Posted by Yadkin

I converted mine to a throttle body EFI and it still likes a rich fuel mixture to restart at the condition that you describe. So I believe this to be inherent with this engine to at least some extent.

I've been thinking of going this route for some time. Which system did you end up installing? How is the performance vs. the stock carbureted motor?

~Steve

[Yadkin]

Originally Posted by sseebart

I've been thinking of going this route for some time. Which system did you end up installing? How is the performance vs. the stock carbureted motor?

~Steve

I went with the FAT EZ EFI 1.0 since it had the best warranty. My old carburetor was being eaten away by the E10 gas available here. As far as performance, it's hard to quantify any power gain since I did a lot of other engine mods before I started having problems with the carb. Cold starting is very good, as is hot starting. Drivability is good, and tuneable.

I did a write up here: Ford Muscle Forums : Ford Muscle Cars Tech Forum - View Single Post - My experience with EFI on the FE

If I was going to do it again I'd go with the same manufacturer but their manifold port injected system, "locked" distributor, with both fuel and spark advance controlled by the ECU.

[Watermelon Jack]

Thanks for the feedback. I decided to start with the basics. When I first bought the car, I knew it needed a fuel pump which i changed out. The car was fine for a while, then when it started to run funny, i ruled out it was a tank of bad gas.The previous owner(s) had installed MSD plug wires and an Edelbrock Carb. Did find the one vacuum port under the carb open as mentioned earlier. Rinsed the dust off the engine for a car show and it wouldn't start, I knew right away new dist. cap, rotor, plug wires and plugs were in order. Found the old plugs were on the sooty side from too rich and the gap was close to/in excess of .050, yet everything else is stock. New plugs were set at .035. Did move the fuel line away from the manifold (close but not touching). Runs very crisp now, still trying to gauge how the warm startups are behaving. Need to check the timing yet. Car had passed Emissions test a while ago, I need to look into the if the Vintage insurance allows EFI upgrade. Cheers

[HeadacheGuy]

The phenolic spacer is probably the best you can do but I just used the thicker composite that would fit an 85 ford truck with a 460 between the aluminum spacer and the carb. They hot soak problem was much better for starting though I still have to give it throttle for about 10 seconds on a hot start to stabilize (I'm still running the original Autolite carb). Fuel bowl contents evaporate rapidly but what makes it worse is that gas will foam when shot into the hot carb. You have to live it to some extend as gas is formulated to operate better under pressure for fuel injection. Today's fuel isn't even close to what it was compared to when our cars will built. If your cooling system is efficient running a 180 degree stat instead of the 192 also helps a little bit.