Is this the real issue?!?

[whitesoc]

Ohhhh don't even get me started on floating grounds....half of last summer was spent with changing V/R's solenoids and then finding the floating ground!:dodgy:

Ken

 

[not2old]

I think you should run the fuel test with a hose from the pump to a can of fresh gas. Check how long it takes if it dstill cuts off. I'm thinking more electrical. If you have a spark tester have it in the system before your 1st try with the can. loose wire in dist. or bad condensor? Do you hear any popping like backfire. Does the coil get hot? check dwell when running possible bad distributor, or points creating too weak spark

Alan L

 

[OLE PONY]

After replacing my fuel tank and fuel pump I used an in-line clear glass fuel filter like others have recommended. I continued to see small rust particles in the fuel filter for several tanks of gas, but it eventually cleared up. I actually am using the original fuel filter at the carb plus the clear glass one to double protect the carb. No obvious effects on performance using two filters. Lots of good tips from others here too. Good luck.

 

[72HCODE]

don't ignore the vapor system in the car.

try this: start the car let it run till it dies, now go to the gas cap and listen to it as you turn it if you hear a air rushing in like opening a can of food with a vacuum, then leave the fuel cap off and start the motor and see how long till it dies.

if it keeps running then your fuel vapor emissions system is most likely full of varnish and gummed up and needs to be replaced.

rust in the fuel is a big issue as well, to truly remove rust you need to completely replace the fuel system. The fuel line can equally be full of varnish and rust. all the OEM fuel lines and vapor lines are just mild steel, after almost 40 years of use they will be completely ruined inside. With the available replacement parts today you are better off saving up a few hundred dollars and completely eliminate a rust problem with the fuel system.

now if you have already replaced the tank and the sender, i would look into a replacement fuel line and a replacement vapor line that runs from the top of the tank up the transmission tunnel up the fire wall to the charcoal fuel vapor canister. you also want to make sure the fuel canister is not clogged with gum.

first and foremost keep all foreign contaminates out of the fuel system, any rust particles can clog up the bowls accelerator pump shot, and idle needles. all the fuel circuits in the carburetor are very small and easy to trap rust and cause a clog in the system.

it would be a good idea to try running the the engine off a separate clean fuel source and see if you have no issues.

your fuel pump might be fine, but its easy to replace, just remove the oil filter to get clearance.

make sure to run an external fuel filter at least temporarily. the glass filters are great to see the fuel but they are dangerous to use for daily use, they can crack and send fuel all over and possibly cause a fire.

try testing the vapor system by running the car till it dies with the fuel cap on, then with the fuel cap off.

if there is no change and the engine is still dieing then you need to look at replacing the fuel line it self and the pump and cleaning out the carb, make sure the fuel is free of all particles.

if you find the gas cap is making a difference in how long the engine runs then you will need to drain the tank remove it and replace the fuel vapor hardline as well as cleaning out the top vent in the fuel tank removing all gum and varnish.

lastly you want to confirm your charcoal fuel vapor canister in the engine bay is not also clogged up.

 

[Chapa]

thanks for all the advice and the testing options! So are these vapor lines easy for find and replace? Just wondering in the case of me having to replace them. So what are the olds of it being a electrical problem if I already know there rust in the fuel system? If the odds are high I may hold off on buying ANYTHING until I know for certain it is or isn't a electrical issue?

 

[jorgem2]

connect a long fuel line from a clean jerry jug of gas to your fuel pump and start the car, let it run for a while to see. Be very careful with the open container of gas. Keep the line away from moving parts and dont trip over the jug.

The metal lines are probably clogged or the rubber lines could be rotten and are letting air in and not letting the pump suck fuel. There are rubber lines near the tank, under the master cylinder and just before the fuel pump, replace all these and blow out the metal lines.

I had a metal line blocked with rust once and I filled it with a funnel full of thinner, let it sit then blew it out with a compressor

 

[coolbluestang]

i had a car do the same thing i had a rubber line as a short gas line and it was week and would close up and not let gas get to carb ,,something to check see if there is any rubber line inline anywhere and check gas filters hope this helps

 

[FastE]

don't ignore the vapor system in the car.

try this: start the car let it run till it dies, now go to the gas cap and listen to it as you turn it if you hear a air rushing in like opening a can of food with a vacuum, then leave the fuel cap off and start the motor and see how long till it dies.

if it keeps running then your fuel vapor emissions system is most likely full of varnish and gummed up and needs to be replaced.

rust in the fuel is a big issue as well, to truly remove rust you need to completely replace the fuel system. The fuel line can equally be full of varnish and rust. all the OEM fuel lines and vapor lines are just mild steel, after almost 40 years of use they will be completely ruined inside. With the available replacement parts today you are better off saving up a few hundred dollars and completely eliminate a rust problem with the fuel system.

now if you have already replaced the tank and the sender, i would look into a replacement fuel line and a replacement vapor line that runs from the top of the tank up the transmission tunnel up the fire wall to the charcoal fuel vapor canister. you also want to make sure the fuel canister is not clogged with gum.

first and foremost keep all foreign contaminates out of the fuel system, any rust particles can clog up the bowls accelerator pump shot, and idle needles. all the fuel circuits in the carburetor are very small and easy to trap rust and cause a clog in the system.

it would be a good idea to try running the the engine off a separate clean fuel source and see if you have no issues.

your fuel pump might be fine, but its easy to replace, just remove the oil filter to get clearance.

make sure to run an external fuel filter at least temporarily. the glass filters are great to see the fuel but they are dangerous to use for daily use, they can crack and send fuel all over and possibly cause a fire.

try testing the vapor system by running the car till it dies with the fuel cap on, then with the fuel cap off.

if there is no change and the engine is still dieing then you need to look at replacing the fuel line it self and the pump and cleaning out the carb, make sure the fuel is free of all particles.

if you find the gas cap is making a difference in how long the engine runs then you will need to drain the tank remove it and replace the fuel vapor hardline as well as cleaning out the top vent in the fuel tank removing all gum and varnish.

lastly you want to confirm your charcoal fuel vapor canister in the engine bay is not also clogged up.

+1 Do not overlook the vapor system.I exsplained how this system worked in another post yesterday.I had the same problem many years ago when I tried to remove my canister system and the fuel pump could not pull due to the vacum build up in the tank.If the tank is not vented you will not run very long.