'70 Charger - Thoughts on installing Fuel Line Check Valve to help reducing starting turns

[matchek]

Hi gents, been awhile. Car needs excessive starting turns when sitting for more than a couple of days especially in the winter months. It's been cold this year too. Summer not as bad where it may be affected after sitting more than a week or two. I saw this Youtube video where someone installed a Carter check valve on an old Pontiac to reduce the amount of fuel that returns to the fuel tank. I have Amazon link below of the part. I was wondering your thoughts on this pros and cons. I have a 67 442 that needs extra turning too but not as much as the Charger. Seems like my Charger system need many extra turns in the not warm/cold months where gets annoying and just thinking of ways to making it easier.

https://www.amazon.com/Carter-169-1...318&sprefix=carter+check+valve,aps,117&sr=8-3

If I didn't want to add a check valve is there anything I can spray in the carb to give it boost? Pour fuel in all in the 4 jets? Thoughts appreciated.

 

[pnora]

Check valve will do nothing for your situation. You could fill the bowls before starting. You also could install an inline electric pump that you manually activate to prime the carb when starting.

 

[Demonic]

No specs from Amazon, what a surprise. Looks like 1/4" pipe thread. If your fuel bowl vents correctly, it shouldn't siphon back to the tank. Fuel pumps have their own valves, so if the pump isn't the issue, it may just be the 10% ethanol in the gas nowadays, unless you don't have that in NC.

What sort of fuel system do you have that has a return?

 

[toolmanmike]

Hi gents, been awhile. Car needs excessive starting turns when sitting for more than a couple of days especially in the winter months. It's been cold this year too. Summer not as bad where it may be affected after sitting more than a week or two. I saw this Youtube video where someone installed a Carter check valve on an old Pontiac to reduce the amount of fuel that returns to the fuel tank. I have Amazon link below of the part. I was wondering your thoughts on this pros and cons. I have a 67 442 that needs extra turning too but not as much as the Charger. Seems like my Charger system need many extra turns in the not warm/cold months where gets annoying and just thinking of ways to making it easier.

https://www.amazon.com/Carter-169-1002-Fuel-Check-Valve/dp/B001UOS7MS/ref=sr_1_3?crid=27HYLSEGGQ38P&dib=eyJ2IjoiMSJ9.bVa6-nyc8B1fdbw1uujd5NpiV9gtkMxn42UYdQm9lZNo_3U5NU818aBxhQzdU-e7iq3VtTw0jbGByMgbkR_v_Sz2wdu7mmToFc3Kt909ixm_LDNPSLdZGVsvyeqSWO9LVzeIBPkdxdZbDlTGoW31mkWgINGJbsTaR8ypoP2ZQO-jaZi6gtXuU2O0nde37uyuz8SN39ULZmylDc6vAICXXOPzVhrNSKD4l54EiPwfE-M.lpnNqrQULg0IspGuHlJ1JBFkHkNs4XDNjTDt7HnfZtA&dib_tag=se&keywords=carter+check+valve&qid=1738506318&sprefix=carter+check+valve,aps,117&sr=8-3

If I didn't want to add a check valve is there anything I can spray in the carb to give it boost? Pour fuel in all in the 4 jets? Thoughts appreciated.

The fuel is evaporating from the carb bowls not draining back into the tank.

 

[toolmanmike]

Hi gents, been awhile. Car needs excessive starting turns when sitting for more than a couple of days especially in the winter months. It's been cold this year too. Summer not as bad where it may be affected after sitting more than a week or two. I saw this Youtube video where someone installed a Carter check valve on an old Pontiac to reduce the amount of fuel that returns to the fuel tank. I have Amazon link below of the part. I was wondering your thoughts on this pros and cons. I have a 67 442 that needs extra turning too but not as much as the Charger. Seems like my Charger system need many extra turns in the not warm/cold months where gets annoying and just thinking of ways to making it easier.

https://www.amazon.com/Carter-169-1002-Fuel-Check-Valve/dp/B001UOS7MS/ref=sr_1_3?crid=27HYLSEGGQ38P&dib=eyJ2IjoiMSJ9.bVa6-nyc8B1fdbw1uujd5NpiV9gtkMxn42UYdQm9lZNo_3U5NU818aBxhQzdU-e7iq3VtTw0jbGByMgbkR_v_Sz2wdu7mmToFc3Kt909ixm_LDNPSLdZGVsvyeqSWO9LVzeIBPkdxdZbDlTGoW31mkWgINGJbsTaR8ypoP2ZQO-jaZi6gtXuU2O0nde37uyuz8SN39ULZmylDc6vAICXXOPzVhrNSKD4l54EiPwfE-M.lpnNqrQULg0IspGuHlJ1JBFkHkNs4XDNjTDt7HnfZtA&dib_tag=se&keywords=carter+check+valve&qid=1738506318&sprefix=carter+check+valve,aps,117&sr=8-3

If I didn't want to add a check valve is there anything I can spray in the carb to give it boost? Pour fuel in all in the 4 jets? Thoughts appreciated.

I made this thread a sticky for easy access. Electric priming pump for fuel evaporation issues.

 

[turbine68rt]

Car needs excessive starting turns when sitting for more than a couple of days especially in the winter months

Are you certain your choke is set correctly and not hanging open on a cold start?

 

[matchek]

Are you certain your choke is set correctly and not hanging open on a cold start?

Hi good question and no, no entirely sure. I just went and opened up the air cleaner and the choke was closed and then I gently opened it and then it retracted. It was a tiny bit sticky to close so I sprayed some Corrosion X on the linkages and it retracted a little better but that doesn't appear - appears normal. On that note, is when the car warms up from a cold start, it revs a little on the high side - the only way to lower the RPMs to normal is while warming up after around 5 to 10 minutes, depending on the weather, I hit the gas pedal hard really quick and then the RPMs drop to normal. At that point I let is warm up or run at the lower RPM. Not sure if it is supposed to drop to lower RPM without doing anything, but that's what I have done since I got it.

Btw, one thing that stuck out is one carb nozzle is not connected to anything. Looking at the carb from the front bumper, on the top of the carb, in the 9 o'clock position, there is a large, around 1/4" nozzle not connected to anything sticking point directly straight to the left. It has a barb where it appears a hose is supposed to connect to it. Perhaps its the bowl vent? I don't see where it could connect to anything. Not sure if that affects anything.

 

[matchek]

No specs from Amazon, what a surprise. Looks like 1/4" pipe thread. If your fuel bowl vents correctly, it shouldn't siphon back to the tank. Fuel pumps have their own valves, so if the pump isn't the issue, it may just be the 10% ethanol in the gas nowadays, unless you don't have that in NC.

What sort of fuel system do you have that has a return?

FYI, I only use ethanol-free gas. I read that the fuel pump is supposed to have a its own check valve so not sure if it goes back to the tank or just the fuel pump.

The car original had a 318, it was replaced with a 72 440. The carb is a Carter 4 bbl. Not sure if that helps with the return. I would assume its stock but not sure.

 

[matchek]

No specs from Amazon, what a surprise. Looks like 1/4" pipe thread. If your fuel bowl vents correctly, it shouldn't siphon back to the tank. Fuel pumps have their own valves, so if the pump isn't the issue, it may just be the 10% ethanol in the gas nowadays, unless you don't have that in NC.

What sort of fuel system do you have that has a return?

The Youtube video guy who used this said it was 1/4"

 

[matchek]

The fuel is evaporating from the carb bowls not draining back into the tank.

I have conflicting info on this. Some say the fuel pump has a check valve and some say it drains back to the tank. Are you sure it drains to the tank? My apologies just want to double check.

 

[pnora]

I have conflicting info on this. Some say the fuel pump has a check valve and some say it drains back to the tank. Are you sure it drains to the tank? My apologies just want to double check.

Forget what you think you know. Fuel enters from the top of the bowl. It can not drain back out through the line. No way no how. Check valves are in the pump and have nothing to do with the bowl going dry. Adding check valves in the line have nothing to do with the bowl going dry. Fuel is evaporating in the bowl. End of story. Amen.

 

[matchek]

Forget what you think you know. Fuel enters from the top of the bowl. It can not drain back out through the line. No way no how. Check valves are in the pump and have nothing to do with the bowl going dry. Adding check valves in the line have nothing to do with the bowl going dry. Fuel is evaporating in the bowl. End of story. Amen.

Thank you very much - makes sense. By the way, to clarify, I understand that the check valve will not prevent the carb bowls from going dry. What the Youtube video meant is that a check valve would help you start your car with less cranks if your fuel fully drains back to your fuel tank and you let it sit for long. The guy had a classic Pontiac and not even sure he was correct in what he is saying. If your car's fuel pump has an internal check valve, then an additional check valve in between the fuel pump and the carb doesn't seem it is going to help start your car any better from sitting at long durations. (I believe his thought is the check valve would keep more fuel in the line).


I guess eventually if the car sits after an extended time, fuel evaporates first from the bowl, then the fuel line downtream of the fuel pump. If it sits a little bit and turn the crank there is fuel downstream of the fuel pump and then fills the bowl. If it sits a very long time and the fuel line is dry, it has to pump fuel from the fuel pump all through the line and then to the bowl. And an electric pump will fill the line upstream of the fuel pump all the way to filling the bowl. Think I got it now.

I would assume any electric fuel pumps would be installed upstream of the stock fuel pump.

 

[pnora]

Thank you very much - makes sense. By the way, to clarify, I understand that the check valve will not prevent the carb bowls from going dry. What the Youtube video meant is that a check valve would help you start your car with less cranks if your fuel fully drains back to your fuel tank and you let it sit for long. The guy had a classic Pontiac and not even sure he was correct in what he is saying. If your car's fuel pump has an internal check valve, then an additional check valve in between the fuel pump and the carb doesn't seem it is going to help start your car any better from sitting at long durations. (I believe his thought is the check valve would keep more fuel in the line).


I guess eventually if the car sits after an extended time, fuel evaporates first from the bowl, then the fuel line downtream of the fuel pump. If it sits a little bit and turn the crank there is fuel downstream of the fuel pump and then fills the bowl. If it sits a very long time and the fuel line is dry, it has to pump fuel from the fuel pump all through the line and then to the bowl. And an electric pump will fill the line upstream of the fuel pump all the way to filling the bowl. Think I got it now.

I would assume any electric fuel pumps would be installed upstream of the stock fuel pump.

Electric Pump goes in the line between the tank and the mechanical pump.

 

[#41]

Fuel is evaporating in the bowl. End of story. Amen.

Except that he says it's worse in the winter than in the summer.

Everything I read here suggest a choke adjustment should be looked into. Also, read up on factory winter starting procedures for the time period. You can improve how the choke is set and carb primed in cold weather by following it....... assuming the choke setting is adjusted correctly. Also, with a carb, you just have to expect that cold weather starting takes a more effort. That is the reality of 1/2 century design.

 

[matchek]

Except that he says it's worse in the winter than in the summer.

Everything I read here suggest a choke adjustment should be looked into. Also, read up on factory winter starting procedures for the time period. You can improve how the choke is set and carb primed in cold weather by following it....... assuming the choke setting is adjusted correctly. Also, with a carb, you just have to expect that cold weather starting takes a more effort. That is the reality of 1/2 century design.

Holy Toledo, after lubricating the choke linkages and let sit for an hour, heard ignition on the second turn and it started on the 3 crank in February!!!! Wow I can't believe it. Normally I'm struggling in the winter.

I noticed my air cleaner is really dirty too. Thanks guys!!! I ordered and new air cleaner and will see what it does next time to see if it works twice in a row.

By the way, for understanding when cold, after it starts, it revs quite high. Is it supposed to calm down after warm? I normally tap the pedal for it to lower RPM. Sometimes I have to go under the hood a move the linkage with my finger to lower RPM. Seems like something is sticking

 

[matchek]

Holy Toledo, after lubricating the choke linkages and let sit for an hour, heard ignition on the second turn and it started on the 3 crank in February!!!! Wow I can't believe it. Normally I'm struggling in the winter.

I noticed my air cleaner is really dirty too. Thanks guys!!! I ordered and new air cleaner and will see what it does next time to see if it works twice in a row.

By the way, for understanding when cold, after it starts, it revs quite high. Is it supposed to calm down after warm? I normally tap the pedal for it to lower RPM. Sometimes I have to go under the hood a move the linkage with my finger to lower RPM. Seems like something is sticking

I think I know why RPMs are sticking high after starting. My throttle return springs are losing tension and it is just keeping the throttle open more than it needs and not retracting back. I bent the springs just to see if it helped and it did. Ordered new ones though . Wow may have fixed two things at once this Sunday - thank you!!!!

 

[dadsbee]

Fuel pump already has a check valve... you don't need two! They only drain back when something holds it open!

 

[67 WS23]

The vapor pressure of today's gasoline is lower than it was in the 60's when a lot of these cars were made, due to emissions regulations. Newer fuel injected cars don't care and always start cold, but carbureted cars need heat in the manifold to properly vaporize today's gas, and may run rough or stall until that happens. Especially at low rpms.

 

[matchek]

The vapor pressure of today's gasoline is lower than it was in the 60's when a lot of these cars were made, due to emissions regulations. Newer fuel injected cars don't care and always start cold, but carbureted cars need heat in the manifold to properly vaporize today's gas, and may run rough or stall until that happens. Especially at low rpms.

Thank you that makes ton of sense. I don't remember as kid in the 70s my parents having to crank our cars as much even in the winter. Granted the cars were technically newer back then but still.

 

[matchek]

Fuel pump already has a check valve... you don't need two! They only drain back when something holds it open!

View attachment 1799592View attachment 1799593

Makes sense as liquid distribution systems in industry typically have a check valve down stream of the pump to ensure the pump always has some pressure.