Fuel pump issues

[Jonas]

1965 300.
So...the car would not start, no fuel to the carb, figured either pump or filter. Bought new pump and a new see through fuel filter. Removed the pump and the pump pushrod, measured 81.8mm or 3.22in or 3 2/9.

I have no idea on how long the pushrod needs to be or should be??

So put it back with the new pump and filter, no go, the pump does pump but wont fill the filter just a tad in the bottom. Just to try I disconnected the fuel line from the tank to the pump and attached a fuel line from the pump to a can with fuel instead in order to rule out a clogged pickup filter in the tank...same thing, it looks like it pumps for sure but not enough...

 

[detmatt]

That's the right length, your problem lies elsewhere.

 

[C Body Bob]

Pour some fuel directly down the carb bowl vent to fill the bowl. This should prime the entire system. If all is good it should start & run good. And stay running. Don't overfill. Just a bit to make sure the floats are off the seats. If that don't do it put a PSI gauge on the pump outlet.

 

[Jonas]

Pour some fuel directly down the carb bowl vent to fill the bowl. This should prime the entire system. If all is good it should start & run good. And stay running. Don't overfill. Just a bit to make sure the floats are off the seats. If that don't do it put a PSI gauge on the pump outlet.

Will do, my experience with carbs are slim close to none so much appreciated. Hence I should ask where the carb bowl vents are....?

 

[C Body Bob]

Will do, my experience with carbs are slim close to none so much appreciated. Hence I should ask where the carb bowl vents are....?

Tube(s) that come vertically up from the fuel bowl. If you are using the old AFB I believe those vent through the step up rods. Not totally sure on those.

 

[Yatzee]

1965 300.
So...the car would not start, no fuel to the carb, figured either pump or filter. Bought new pump and a new see through fuel filter. Removed the pump and the pump pushrod, measured 81.8mm or 3.22in or 3 2/9.

I have no idea on how long the pushrod needs to be or should be??

So put it back with the new pump and filter, no go, the pump does pump but wont fill the filter just a tad in the bottom. Just to try I disconnected the fuel line from the tank to the pump and attached a fuel line from the pump to a can with fuel instead in order to rule out a clogged pickup filter in the tank...same thing, it looks like it pumps for sure but not enough...

Rod is 3 1/4 long (+/-). If the bowls are empty, the float valves are already off their seats, adding fuel will seat them. You need to see fuel coming out the pumps discharge line. Service manual will give you a time/volume measurement. Remove the line, put it in a small mouth bottle and crank the engine with the coil ignition wire removed to check the value and see for yourself if it's pumping. There is a screen at the inlet to the carb beneath the the threaded fuel line adapter fitting if it's a Carter. Check it for clogging.

 

[C Body Bob]

Rod is 3 1/4 long (+/-). If the bowls are empty, the float valves are already off their seats, adding fuel will seat them.

No, the floats not the needles or plungers. I'm talking about the floats at rest on the bottom of the bowl. Adding fuel into the bowl will allow the engine to start & run normally. As opposed to using the starter to try & pump it up. It's just way easier. If it dies out after a minute then it's not getting fuel to the bowl.

 

[CBODY67]

The bowl vents in question should be inside the air cleaner's "ring", where it seats on the top of the carb. The vent tubes should have 45 degree "slash" at the top. Usually one near each of the primary throttle bores. The external bowl vent is open at normal hot idle, but closes when the throttle is opened, by a linkage to the throttle linkage on the side of the carb.

For the record, 2bbls usually have just one, near the center, straight-cut on the top, inside the "ring".

CBODY67

 

[C Body Bob]

The bowl vents in question should be inside the air cleaner's "ring", where it seats on the top of the carb. The vent tubes should have 45 degree "slash" at the top. Usually one near each of the primary throttle bores. The external bowl vent is open at normal hot idle, but closes when the throttle is opened, by a linkage to the throttle linkage on the side of the carb.

For the record, 2bbls usually have just one, near the center, straight-cut on the top, inside the "ring".

CBODY67

Correct

 

[Jonas]

So, continued today. Removed fuel line fitting from the carter afb, removed screen, looks ok. Removed fuel line from carb to pump and blew through with compressed air just to be sure. Put some gas down the bowl vents on the primary side. Opened the choke plate and moved the throttle so that I could see that some fuel squirted....tried to start...no go, have checked and verified spark. Will start for some revolutions with some start gas into the venturi...
And the pump will not put any fuel into the filter...
Snapped some photos:

 

[Jonas]

Here's a stupid thought...I haven't switched the lines on the pump have I? The rear one should go to the tank right...? Seems logical... Never mind, the fittings are not the same, just a hose fitting to the tank and a hard line fitting to the front...so that can't be it.

 

[detmatt]

Time to check your timing. Pull the #1 plug, disable the ignition system and get the #1 piston up to tdc on a compression stroke. Once you know you're there mark the #1 position from the cap onto the distributor with a marker and pull the cap to see if the rotor is pointing at the mark.

 

[Jonas]

Did that a couple of weeks ago...checked the timing that is. But if it is not getting any fuel though...it doesn't matter. For the amount of time I've been running this on the starter I would have thought that the pump would at least have filled the filter just above it with fuel...the new pump might be off...

 

[detmatt]

If you poured some gas into the carb and saw it actually squirt out the nozzles I would think it should at least cough and sputter. When reviving my Imp from a long slumber when I first bought it we were just pouring gas down into the air horn right into the intake, putting the air cleaner on including wing nut and starting it. It ran for 10 to 15 seconds every time.

 

[Jonas]

So, filled the bowls as much as I dared, pulled the fuel line from the carb and filled fuel down to the filter...boom, fired right up. So I guess i didn't fill the bowls enough perhaps. But it is still running off a can so now I will connect it to the tank and see if it still runs. Though the stuff coming out of the tank, well, you'll have to be a real optimist to call that nice...so I will probably need to remove/clean/seal the tank or replace it.

 

[C Body Bob]

So, filled the bowls as much as I dared, pulled the fuel line from the carb and filled fuel down to the filter...boom, fired right up. So I guess i didn't fill the bowls enough perhaps. But it is still running off a can so now I will connect it to the tank and see if it still runs. Though the stuff coming out of the tank, well, you'll have to be a real optimist to call that nice...so I will probably need to remove/clean/seal the tank or replace it.

Yep it depends on how long the car has sat. It's a guessing game. Glad you got it to run which eliminates that. So if you got trash in your tank that's getting up to the pump that likely is your problem. Gary was able to same my tank on my 300 by soaking small amounts of white vinegar & then sealing it. Took a month by worth it to keep from have to find a new or better tank