1972 440-4 Difficult start after not being driven for several weeks

[Davison]

I have a 1972 Road Runner GTX that runs great, except when it sits for longer than a day or two. It is a well-kept original car, original carburetor, the engine and trans have never been opened, etc., less than 30,000 miles. The last time the carburetor was rebuilt was in 2018, and the fuel pump was replaced at that time, but it exhibits the same problem as it always has: if the car sits for more than a few days, say two weeks, it is very difficult to start. There just is no fuel at the first, second, or third crank. I can understand this for the first start after sitting for months during the winter, but not after days or a few weeks. Here is what I do to start it: I press the accelerator to set the choke, turn the key to engage the starter, crank for 10 seconds or so, stop the crank, pump the accelerator pedal, crank again, repeat several more times. Usually after the fourth or fifth time of this procedure it starts. then it runs great. Hot starts are instantaneous, as are warm starts. The car does not hesitate or buck when cold.

Does anyone have any ideas on how to fix this problem? Thanks.

 

[MWbirdLOVER70]

Have you pressure texted your needle and seats? Sounds like bowls dry out but what do I know lol

 

[dadsbee]

Sounds like you're running ethanol crap. I can leave my cars all Winter long and they'll start on the 2nd crank running 33% AV gas to Shell 92 premium. That or the check valve in your fuel pump is leaking allowing the fuel line to drain back to tank.

 

[WileERobby]

It's the evaporation of the gasoline these days. Nothing wrong with your car.

 

[WileERobby]

On my bone-stock Cordoba, I'll squirt fuel in the carb on a cold start ( I use a mustard/ketchup squirter ), since all the fuel in the bowl has evaporated. My timeline with this car is a couple of days, after that it's squirting time. Runs like a top otherwise. I could drive this car coast-to-coast and back with zero issues.

 

[WileERobby]

My only other advice is to sell me your car dirt cheap. That will solve your problem, and make me happy. Win-win !

 

[toolmanmike]

It's the evaporation of the gasoline these days. Nothing wrong with your car.

Absolutely. Puppy pee gas nowdays. Even the ethanol free is bad.

 

[pnora]

Plumbing in a electric pusher pump would work.

 

[Davison]

It's the evaporation of the gasoline these days. Nothing wrong with your car.

Wow, Thanks for the three quick replies. So some answers: 1. no I have not pressure tested the needles and seats as I thought the rebuild would have handle that but I can have it checked. 2. fuel used is Sunoco ethanol free unleaded 90 octane. 3. Fuel pump check valve-yes, I had thought of that but this hard start condition existed with the old fuel pump (which was the original one) and now with the new Delphi pump.

 

[ykf7b0]

I will suggest 2 or 3 pumps on the accelerator and not setting the choke. What type of carburetor are you using? Thermoquad?

 

[turbine68rt]

Have you physically looked to see that there is no fuel coming from the discharge nozzles or is it a choke setting issue? When cold is the choke fully closed? Like @dadsbee I can go days or even over a week and it doesn't take long at all to start.

 

[dadsbee]

I can seriously go 4 months or more and start on the 2nd crank. Holleys and even the original Carter on the Bird.

 

[ykf7b0]

I don't even have a choke horn and I'm cold starting after 2 or 3 pumps. The car might die a time or two until it will hold an idle but never an issue.

 

[AR67GTX]

Ethanol evaporates very quickly out of vented fuel bowls. Holleys - Carters - doesn’t matter. They all have ventilated fuel bowls. I use these to prime the carb after it sits for several days.

As an alternative you can get in, don’t touch the gas, turn the key for about 5 - 6 seconds, pause, crank 5 - 6 seconds again, and again, then pump the throttle fully 3 or 4 times to prime the engine and set the choke, pause a few seconds to allow some vaporization and then turn the key to start the motor normally. I just personally don’t like to spin a cold motor ove4 this much so I prime.

 

[Davison]

I will suggest 2 or 3 pumps on the accelerator and not setting the choke. What type of carburetor are you using? Thermoquad?

It is the original Holly carb. It has been rebuilt several times over the years. Last time in about 2018. Probably only 2,000 miles ago.

 

[ykf7b0]

It is the original Holly carb. It has been rebuilt several times over the years. Last time in about 2018. Probably only 2,000 miles ago.

I suggest priming the carb to see how it reacts. If it fires right off then you have proof the bowls are not holding fuel or the choke is possibly too tight.

 

[WileERobby]

Ethanol evaporates very quickly out of vented fuel bowls. Holleys - Carters - doesn’t matter. They all have ventilated fuel bowls. I use these to prime the carb after it sits for several days.

View attachment 1521924

I just personally don’t like to spin a cold motor over this much so I prime.

Yup. Exactly why I went to the mustard squirter, like yours on the left. I changed the starter a few years ago, I'm not burning up a starter due to crap gas.

 

[Geoff 2]

The real fix is an electric fuel pump [ Carter #4594, will last forever ]. Use it as stand alone, NOT with the factory pump.

 

[turbine68rt]

Yup. Exactly why I went to the mustard squirter, like yours on the left. I changed the starter a few years ago, I'm not burning up a starter due to crap gas.

Op said he is using ethanol free fuel in post 9.

 

[moparedtn]

The real fix is an electric fuel pump [ Carter #4594, will last forever ]. Use it as stand alone, NOT with the factory pump.

Noisy?