383 engine stopped pumping fuel

[dacci]

383 engine stopped pumping fuel.
I put in a new fuel pump and still no fuel. the engine turns normally, the pushing finger of the pump walks without problems. fuel filter is empty. Why can not pump fuel? tank is almost full.

 

[Toolmanmike]

383 engine stopped pumping fuel.
I put in a new fuel pump and still no fuel. the engine turns normally, the pushing finger of the pump walks without problems. fuel filter is empty. Why can not pump fuel? tank is almost full.

Did you check your fuel pump pushrod for wear?

 

[dacci]

Did you check your fuel pump pushrod for wear?

looks great on the outside

 

[Davea Lux]

Start checking the rubber hoses, there is one back by the fuel pick up for the tank, another at the rear of the stub frame and the one by the pump itself.

Dave

 

[detmatt]

looks great on the outside

You’ve got to pull it and measure it.

 

[HWYCRZR]

Rod should be around 3.2” long.
I recently had to replace mine. With the short stroke it wouldn’t keep up with the fuel needed.
In-line electric fuel pump for emergency fix? 68 Polara.

Pictures of the difference here.
After 34 years road-trip with the Polara back to Montana

 

[stubs300]

looks great on the outside

Just because something looks good, doesn't mean it is! Pull it out and ******* measure it for God's sake! There was an idiot yesterday that said the same thing on a different board, was it you?

 

[CBODY67]

The fuel pump pushrod acts the same as a pushrod that goes to a rocker arm for an intake valve in the cyl head. With time, the fuel pump push rod will wear at the camshaft end, decreasing its length. It might still move as normal, BUT with a shorter length, not as much input to the lever on the fuel pump. In the cyl head scenario, with the shorter pushrod length, the intake valve will not open nearly enough for good performance, yet it still opens.

Hope this might explain things a bit better.

Be sure to coat the new pushrod with camshaft lobe assembly moly paste, for best initial "help" in getting a good start on life. Pushrods can vary as to source and hardness of the metal, by observation, so getting a good one can be important for a long service life.

Just some thoughts,
CBODY67

 

[Big_John]

I think the answer is obvious...

The gas is too expensive and the pump just can't bring itself to pump the liquid gold out of the tank to be burnt.

But seriously, a pin hole in any of the hoses or line on the suction side will cause a problem. And! As we've been seeing in the last 10 or so years, just because it's new, doesn't mean it's good. Another thing to try is to disconnect the line at the fuel filter and see if it pumps gas while you crank the engine. A screwdriver, rubber hose and a soda bottle are your tools needed.

 

[jollyjoker]

I had a similar bizarre situation a few years back, after replacing fuel pump. Seemed like it just wouldn't pump the gas up to the carb. Worked my way up, systematically d/c fittings to make sure it was pumping (like Big John said). Finally d/c at the carb, and used a vacuum pump on the line, until I had gas running through. Reattached, and it fired right up. No problem since. Figured it must have been some sort of an air lock . . .

 

[Boydsdodge]

You’ve got to pull it and measure it.

Two bad push rods same engine. Three good, not going in to be chewed up. Went with an electric pump.

 

[Mudeblue]

383 engine stopped pumping fuel.
I put in a new fuel pump and still no fuel. the engine turns normally, the pushing finger of the pump walks without problems. fuel filter is empty. Why can not pump fuel? tank is almost full.

Put in an electric pump, call it an EV, file for a tax credit, problem solved!

 

[dacci]

on the left is the old pusher, on the right is a new one, replaced with a new one, there is no sense.

but I noticed that the fuel pump, which I changed 3 months ago, does not even pump gasoline into manual. I took off gasoline, I try to pump it manually and I don’t feel that it is pumping something. I suspect that the pump turned out to be defective and did not last long.

 

[Boydsdodge]

Before you install pushrod, don't for get the break in lube.

 

[SuperDave]

If you're burning the cheap stuff (ethanol blended gasoline), it'll eventually eat thru the rubber fuel lines. Getting to the hoses under the hood is easy, the hoses from the tank to the hard lines along the bottom of the car not so much. When I rebuilt Project Turd, I nearly had to drop the tank to get to the hoses on the top of the tank. I KNEW ethanol was the future, there WILL come a day that gasoline will be extinct, or that I may have no choice BUT to run Ethanol blend. So I made the choice to purchase ethanol friendly hoses and an electric pump near the tank. (Twice the price but worth it for peace of mind) Even the vacuum lines too. To this day it has never seen a single drop of ethanol. But there may come a day that I'll be needing fuel and pure high octane gasoline may not be available, so it's capable. The Edelbrock carb mounted on the motor is also built for ethanol also.

If I were you, I'd remove the mechanical pump and install an ethanol friendly electric pump near the tank. Pull ALL the rubber fuel lines and replace with ethanol friendly hose. It's my guess the hoses on the tank are original, it has seen ethanol and has dry rotted and allows air suction. To my knowledge, no one makes an ethanol friendly mechanical pump, the diagram is rubber, and won't last but a few years at best. That way you're future proof. In the years ahead older cars may only be running corn liquor, and any rubber under the hood will be for coolant only.