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69 Roadrunner Hard to Start After Setting for Long Periods

amike95

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My 69 Roadrunner (383) will start right up if started weekly, but if it sets, for say, a month, I have to pump the accelerator numerous times before it will start. Once it starts it runs fine. It's almost like after setting the fuel line loses prime or something. Any suggestions? Thanks,
 
It's a combination of maybe drain back, and evaporation. It's much worse with Carter style carbs. I ended up putting an electric fuel pump on my 340 Dart for when its been sitting. Then I run it on the mechanical fuel pump. Didn't want to do it, but it's better than grinding the crap out of the starter.
 
Go TBI cause the days of the carb have come and gone. Just ask Edelbrock, Holley, FiTech and MSD cause that's the direction their going.
 
It happens with my Belvedere I got. After a couple of weeks sitting around I dump a little gas down the carb and that usually does it.
 
Normal. Characteristic. Made worse by ethanol.
 
Yeah drain back, fuel is draining back from the bowls back through the pump and back into the lines where it sits until the pump can get it back up to the bowls takes a few seconds I do the old 2 pump and fire works everytime. Todays gas is full of ethanol and it evaporates and is not as thick? if that's the word for older motors.
 
IMHO, this should be a non-issue. You should be turning the motor over to bring up oil pressure before starting the car after sitting a while, and that should be more than enough to fill the bowls with fuel.
 
Any pics of your electric fuel set up Furyus...?
 
Normal. Characteristic. Made worse by ethanol.

My old Belvedere is the same way and has been for years. The combination of the ethanol in the gas and having a cold intake makes for a hard start. One thing that I did that helped a little was going to a manual choke on the Eddy 750.
 
IMHO, this should be a non-issue. You should be turning the motor over to bring up oil pressure before starting the car after sitting a while, and that should be more than enough to fill the bowls with fuel.
Definitely with you on this one. With no oil up top why would you want it to start. This is why prining is so important. Oil pressure then fuel.
 
The electric fuel pump does not help this condition. I don't plan to prime the engine after setting one month. Check the oil level, let the electric pump run for a few seconds and three times to the floor. Then, keep a close eye on the oil pressure to be sure it builds. Keep your ears open.
 
The electric fuel pump does not help this condition. I don't plan to prime the engine after setting one month. Check the oil level, let the electric pump run for a few seconds and three times to the floor. Then, keep a close eye on the oil pressure to be sure it builds. Keep your ears open.

I agree, priming the engine after sitting for a month isn't necessary. However, after sitting for a few months this past winter, it took over a minute of cranking for me to bring up oil pressure - so I was definitely tempted to get out and prime it.
 
I agree, priming the engine after sitting for a month isn't necessary. However, after sitting for a few months this past winter, it took over a minute of cranking for me to bring up oil pressure - so I was definitely tempted to get out and prime it.
What is the easiest way to do this?
 
What is the easiest way to do this?

For me, I just crank the motor over for maybe 15 seconds, let it rest for maybe 5-10 seconds, then repeat until oil pressure builds. I can see my gauge come up but I also kept the dummy light so I can confirm it. Then I pump the gas a couple times and she fires right off every time.

I only ever had to prime my Holley 750 once and that was when my fuel pump pushrod was worn down so I would suck the bowls dry when I'd get into the throttle. That's a really easy process - use a turkey baster to squirt some fuel into the bowls from the top of the carb. Super simple, but not usually necessary, as cranking the motor to build oil pressure also cranks the fuel pump and fills the bowls very quickly.

As far as priming the oil pump, I also only had to do that once, when it was sitting for maybe 4-5 months over a long winter. I just marked the dizzy, pulled it and used a priming rod on a cordless drill. Probably took 10-20 seconds for the oil pressure to come up. I then put the dizzy back in, set it to the marks and drove it out of the garage.
 
Yeah drain back, fuel is draining back from the bowls back through the pump and back into the lines where it sits until the pump can get it back up to the bowls takes a few seconds I do the old 2 pump and fire works everytime. Todays gas is full of ethanol and it evaporates and is not as thick? if that's the word for older motors.
I am not buying into the drain back theory. The carb bowls are vented and fuel sets well below the seats. That would be like trying to syphon water out of a open bucket with a hose and never put the hose in the water.
 
Having the same problem with 69 RR 383ci with Edelbrock 1405 anytime after 1 week I have to add gas
to top of carb to start even using the manual choke. Do you think it might be fuel pump or small hole in
fuel line causing it to bleed down. Sometimes even drains battery down trying to crank. thanks for any and all input
 
The problem I have with my Bee and my Satellite is that if they sit for a couple months, not only does the fuel evaporate out of the bowls, but the float needles stick shut. I have to whack the top of the carbs with a small plastic mallet to ge them to start. PITA but manageable now that I know the drill. Running ethanol free premium doesn’t seem to help.
 
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