Jump to content

Fuel pump install...lever in block?


Purple Moo Cow

Recommended Posts

So I went to rebuild the carb and everything looks almost new in it. Checked my rebuilt fuel pump and while it pumps gas by hand, does not shoot any fuel out in the engine. Did a bit more digging on here, I'm curious, is there some sort of rod in the engine that I need to somehow hold up to get the fuel pump to pump fully? Apparently you use Vaseline? 

Link to comment
Share on other sites

No, there is no pushrod.  there is a lobe on the cam that acts directly on the lever.

 

From the manual

 

2. FUEL PUMP
The fuel pump is operated by an eccentric on
the camshaft which actuates the rocker arm. This
action lifts the pull rod and diaphragm assembly
upwards against the diaphragm spring creating a
vacuum in the valve housing which opens the inlet
valve. Fuel is then drawn into the valve housing
chamber.
On the return stroke of the rocker arm, the diaphragm spring forces the diaphragm down, the
inlet valve closes, and fuel is forced through the
outlet valve to the carburetor.

 

Link to comment
Share on other sites

@keithb7 Yes I have a lever very similar to that, just a glass filter on the bottom. I was under the impression the fuel pump only fits in in one way. That you kind of just make it fit into where the cam is, not necessarily adjusting anything but might have some resistance putting it in

Link to comment
Share on other sites

Hi, I did mine not that long ago and found that when I installed the new pump I had to put some pressure on the arm to get the pump to sit right and the bolts to go in. The pump did not go straight in it had to fit under the lobe on the cam in order for it to pump. My guess is that if the pump isn't working well when on the engine but is in your hand then perhaps you should take a close look at the lobe on the cam to see if it is badly worn. Other than that I can't give much advice. Good luck keep us posted.

Link to comment
Share on other sites

There can be resistance. Yes you may not have the arm sitting on the lobe properly. Easy fix. Loosen all 6 spark plugs. Turn fan blade 120 or so degrees. Try re-installing pump. Rinse and repeat. Easy peasy.

 

If you are installing an electric fuel pump, you may need a regulator. A auto power off switch too if you want to be safe. 

Edited by keithb7
  • Thanks 1
Link to comment
Share on other sites

4 minutes ago, keithb7 said:

There can be resistance. Yes you may not have the arm sitting on the lobe properly. Easy fix. Loosen all 6 spark plugs. Turn fan blade 120 or so degrees. Try re-installing pump. Rinse and repeat. Easy peasy.

 

If you are installing an electric fuel pump, you may need a regulator. A auto power off switch too if you want to be safe. 

I will give that rotating the fan blad stuff a try, there's always a possibility that could do something. 

 

I'd buy a fuel pump that has an output close to the mechanical fuel pump. Good look on the auto power off switch. ? 

Link to comment
Share on other sites

Install the fuel pump on a slight angle meaning to make sure the arm is either over or under the cam lobe - not sure but I think it goes on top. Look at your old one and see where the cam lobe rubbed on the arm - top or bottom.

Anyway, angle the fuel pump into the block with the arm on or under the cam lobe and catch one mounting bolt into the block - leave it loose.

Then either push or pull the fuel pump up or down - depends on orientation of the arm as stated before - and line up the other bolt in the block and then tighten both bolts.

BTW - when you align the second bolt by "twisting" the pump you should hear the diaphragm make a suction sound and there should be some resistance. That's how you know the pump is in correctly

 

Link to comment
Share on other sites

@keithb7 my fuel pump has the straight lever...does the bent one only work on certain vehicles vs the straight lever?

 

From the way it shows in the picture I honestly don't even know how it's possible to get the pump installed flush with the bolts snug/tight, and not have the lever where it belongs on the cam. 

Link to comment
Share on other sites

I obtained and store here, about 7 spare fuel pumps here of various designs. All are used on various Mopar flatheads. They all basically work under the same principle.  Some cars used the bent lever, some the straight. I can't say why as my experience across many model Mopar cars is limited. Perhaps someone else here will chime in. Can a bent shaft pump seen above be used where a typical straight shaft is used?

Edited by keithb7
Link to comment
Share on other sites

45 minutes ago, keithb7 said:

I obtained and store here, about 7 spare fuel pumps here of various designs. All are used on various Mopar flatheads. They all basically work under the same principle.  Some cars used the bent lever, some the straight. I can't say why as my experience across many model Mopar cars is limited. Perhaps someone else here will chime in. Can a bent shaft pump seen above be used where a typical straight shaft is used?

Straight and 90° will interchange they just pump at a slightly different spot in the rotation. I will say when installing a fresh pump I've found to get it started the engine needs to be running by dumping a little down the carb. For some reason just battery cranking isn't enough to get them going 

Link to comment
Share on other sites

10 hours ago, Young Ed said:

Straight and 90° will interchange they just pump at a slightly different spot in the rotation. I will say when installing a fresh pump I've found to get it started the engine needs to be running by dumping a little down the carb. For some reason just battery cranking isn't enough to get them going 

 

Well I am willing to fill my carb float bowl area with gas and see what happens when I crank the motor. I just rebuilt the carb so I haven't put the air horn on the gasket tight yet. I guess I'll see what happens tomorrow! Oh the joys of learning about old...old...old cars

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.

Terms of Use