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Fuel pump not working after replacement

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Discussion starter · #1 ·
Ok, so stemming from my other problem, I cannot get gas into the carb. I thought the fuel pump was bad, so I replaced it.

Now the new one doesn't work, also.

I ran a rubber hose from a bottle of gas to the pump to the carb and the line was still bone dry.

What could cause this?
 
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#2 ·
With a cup of fuel poured into the carb bowl and engine running, you could measure the vacuum the pump creates on the inlet side.
If vacuum is registered, then you may need to replace the rubber hose sections at the tank, two of them, one at the sending unit to hard line and the other section right behind the pass rear tire on the frame rail.
After replacing those two sections, you may need to prime the line to the pump inlet by disconnecting the inlet hose to fuel pump and inject very low pressure air into the fill tube and use a rag to adapt the blowgun to filler tube. Once fuel comes out inlet hose, reconnect to pump.

No pump vacuum, pump diaphram broken or fuel pump rod missing or not on fuel arm, but then pump would not bolt up the block.
 
#3 ·
Please tell me you djdn't forget to remove the bolt that holds the fuel pump push rod while you replaced the pump. That can cause nasty problems.
 
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Discussion starter · #4 ·
Everett#2390 said:
With a cup of fuel poured into the carb bowl and engine running, you could measure the vacuum the pump creates on the inlet side.
If vacuum is registered, then you may need to replace the rubber hose sections at the tank, two of them, one at the sending unit to hard line and the other section right behind the pass rear tire on the frame rail.
After replacing those two sections, you may need to prime the line to the pump inlet by disconnecting the inlet hose to fuel pump and inject very low pressure air into the fill tube and use a rag to adapt the blowgun to filler tube. Once fuel comes out inlet hose, reconnect to pump.

No pump vacuum, pump diaphram broken or fuel pump rod missing or not on fuel arm, but then pump would not bolt up the block.
Click to expand...
Everything from the sending unit (but not including) to the carburetor is brand new. The lines and rubber lines and all brand new.

scblucam said:
Please tell me you djdn't forget to remove the bolt that holds the fuel pump push rod while you replaced the pump. That can cause nasty problems.
Click to expand...
Can you explain this further? I did some research and just NOW found out that theres a push rod that activates the pump, I didn't notice anything while changing the pump. Is it possible its missing?

If it was missing, would I be able to get to the pushrod by taking off the passenger side valve cover?
 
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#5 ·
Pop the pump off and if the pushrod is there you can see it or at least stick your finger in there and feel it if it's hung in the block. It's not typical for it to hang in the block when you pull the pump out but it could happen. It has to be pushed back when the pump is installed so that you can get the pump lever in. If you need one, you just remove the two smaller bolts on the pump plate on the block once the pump is removed and insert it.

It's not uncommon to have to prime the pump if you changed out everything. It can take awhile for the pump to pull fuel through a fresh install. I've just removed the line from the carb and sucked it to prime the pump on occasion. Do so at your own risk.
 
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#7 ·
I ran a rubber hose from a bottle of gas to the pump to the carb and the line was still bone dry.
Click to expand...
Assuming u have the pump rod in....a dry diapham pump like most fuel pumps are not self priming...often they have enough suck to get a little fuel to them, once 'wet' pump nice.
BUT if there is the slightlest air leak in the fuel lines before the pump it will stop pumping.
A quick way to get fuel to the pump is a vaccuum cleaner on blow in the fuel tank..or low air pressure.
Not uncommon on older cars when they used to run out of gas.
 
#9 · (Edited)
BPOS said:
Eeew
Click to expand...
What's the matter...aint ya ever kissed a Holley before ? Double Pumper ??


Yeah, I've had to prime my pump a time or 2 after setting for a year or more. I disconnect the line from the carb and using a short length of hose and a small funnel, dribble a few drops (maybe an ounce) down the line. As Steps mentioned, gives diaphragm new life.
 
#10 ·
Sounds like you are missing the fuel pump. There is a extra lobe on the cam that this rod operates off of, and it pushes the lever on your fuel pump. As stated, take the pump off and feel/look up in there. If it's not there, time to get one.
 
#12 ·
When I've had problems priming a fuel pump its been resolved by putting an air gun wrapped with a shop rag in the fuel tank filler hole to create a little pressure to move the gas to the pump. You can do this while having someone crank the engine or remove the inlet line at the pump until you have some coming out. You don't need much pressure at all, and you won't create much pressure in the tank because the towel won't seal perfectly.
 
#13 ·
Whats the history on this car and its fuel issues? Did it run before with the previous pump? I would think that you would notice that there was nothing for the pump arm to contact if the rod was not there when you installed it. You should pull the pump and make sure the rod is in place. As far as holding the rod in place while the pump is out I have used grease on the rod before, just enough to hold it up there. Also prime the pump by adding a little fuel down either side like mentioned before.

BTW Joe this is a family site, please don't post pics of your pump rod hanging out like that... :)
 
Discussion starter · #15 ·
I think it might have been the pushrod.

I installed it like this...

Image


How can I reset the pushrod to install the pump properly?
 
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Discussion starter · #16 ·
Calpantera said:
Whats the history on this car and its fuel issues? Did it run before with the previous pump? I would think that you would notice that there was nothing for the pump arm to contact if the rod was not there when you installed it. You should pull the pump and make sure the rod is in place. As far as holding the rod in place while the pump is out I have used grease on the rod before, just enough to hold it up there. Also prime the pump by adding a little fuel down either side like mentioned before.

BTW Joe this is a family site, please don't post pics of your pump rod hanging out like that... :)
Click to expand...
No real history that I know of. The car was started without the pump (the guy I bought it from dumped fuel straight into the carb), and it ran fine. The first few times I started the car, there was fuel in the lines (all brand new lines, so it was new fuel) and the pump just... stopped working. Weird, but I assumed possible.
 
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#17 ·
The rod just floats in there. I use a small flat piece of wood, like from a wire brush handle. It's thin and wide enough to hold the rod up while you insert the pump.
You could use a small flat-blade screw driver or a thin ruler.

You're good, you just forgot to push the rod all the way in before you put the pump arm in. Put a dab of grease on the end of the rod or tip of the arm. Push the rod up inside and hold it there while you insert the pump arm. You might be able to see the rod fall back out and make contact with the pump arm. Then yer good!
 
#18 ·
As Joe says above, a bloody good dollup of grease
this method is great for holding screws on screw drives, inside sockets and sticking notes to a wall...and works better than hair cream lol

And a quick test of a pump, out of the car...pour a little petrol , kero, what ever in to the pump...bloke off the inlet and out lets with your fingers and pump it.
you will feel the suck and pressure.....but as I mentioned above, diapham (and gear) pumps need to be primes to work......
 
Discussion starter · #19 ·
Oh my God. I pulled the pushrod out because I couldn't move it. It's bent, and not just a little. It's a massive bend.

Image


Here's where it bent.

Image


What could have possibly caused this? This is one thick pushrod...
 
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#20 ·
Looks like as I said someone left the bolt in. On the front facce of the block there are two screw holes. one shoul have a short capscrew in it to keep oil from leaking. It lines up with the pushrod. You can put a longer bolt in to contact the push rod to hold it up while you install the pump. DONT FORGET TO CHANGE IT BACK TO THE CAP SCREW or you could bend the rod or wipe out the ecccentric lobe on the front of the camshaft. Grease is better. At least you found the problem IF the eccentric is not wiped out. Then your options are change the cam or install an electric fuel pump.
 
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