Holley 94 accelerator pump issue

P

Panheadguy

Member
Top of the carb is off. Bottom on the bench with float chamber full of fuel. The link is in the hole for the most squirt.
Almost nothing is squirting out. I am operating the throttle through full travel so the pump plunger is coming to the top. The check ball and (pump) inlet needle are free. squirting carb cleaner through the passages confirms no internal blockage.
This all after I decided that I probably needed new pumps due to age and they seemed sloppy in the cylinder. I bought new pump plungers from Charley Price.
I'm at a loss.....I thought I knew all about these carbs but now not so sure. Ideas anyone?
 
Try installing the old one and see if it squirts.that will at least tell if you got a bad part.was the new plunger made of leather?
 
Charley NY is the Charlie you want to deal with. You can actually make your own plunger wipes out of soft leather, oiled up. Check the ball bearing check valve in the bottom. it might be stuck, or missing altogether.
 
not sure what "passages" are being referred to, but...

i found the accelerator jets or nozzles, if that's what they are called, were plugged in my carb. when cleaned out i found the pump to be working well enough. a little, very little, disassembly was necessary to remove and clean them. all the info to do the job was easily found on youtube.

OTOH, if replacement is warranted, the accelerator pumps are readily available online and often in carb rebuild kits along with a bunch of other stuff.
 
Thanks for the suggestions. The pump plunger is one of Vintage Speeds new blue ethanol proof stlyle. By passages I mean all the internal conduits between the pump and the squirters.
Don't know Charlie in NY but will call Charlie in FL Monday If I can't figure out the problem
 
Panheadguy said:
Thanks for the suggestions. The pump plunger is one of Vintage Speeds new blue ethanol proof stlyle. By passages I mean all the internal conduits between the pump and the squirters.
Don't know Charlie in NY but will call Charlie in FL Monday If I can't figure out the problem
Click to expand...

Ain’t nothing wrong with Price’s blue pump plunger. I’ve got one in my Edelbrock 94 that I just freshened up a couple of months ago. That entire pump well and linkage design is “interesting”….. and we’ll leave that at that. Not how I picture an ideal design though. Crack kills, comes to mind. I love engineers as you can probably guess.
From what I saw, having rebuilt hundreds of Holleys, Autolite and Rochesters, the 94 better be clean internally or you’re going to have issues. I’ve seen squirters that were easier to clean. That’s for sure.
 
Make sure each side of the pump discharge nozzle assembly (the thing with the two passages where the accelerator pump squirts out) is clean. I use a single strand of copper wire from a multi strand wire to gently poke out any crud in each side. I like to hold the discharge nozzle assembly upside down at a sink with hot water flowing into the center and see two good matched streams of water out of each side.
 
You have the needle under the discharge nozzles? Have you given it a small rap with a hammer so it seats properly. You can also tap the ball under the pump so it also seats.
 
Terry.OH This is something I had not thought of. It is possible with passing of time some corrosion has trashed the seating area for both the ball and needle. This would definitely affect the operation. For those that keep suggesting dirt; I have an ultrasonic cleaner and have squirted carb cleaner through every hole and passage.
 
There are 2 non return valves. One is a ball in the base of the plunger cylinder. One is a needle valve in the hole where the squirters screw in.
The passages may all be clear but if the non return valves are stuck or not seating it will not squirt.

This video may be useful:

https://youtu.be/UMiWUQyIkmg

Mart.
 
Mart said:
There are 2 non return valves. One is a ball in the base of the plunger cylinder. One is a needle valve in the hole where the squirters screw in.
The passages may all be clear but if the non return valves are stuck or not seating it will not squirt.

This video may be useful:

https://youtu.be/UMiWUQyIkmg

Mart.
Click to expand...

my understanding is similar and along the same lines...

while i had my 94 disassembled i became curious as to why there were two mechanisms serving as what could be described as check valves and why they were different.

it was clear that the ball was necessary. for when unseated by the vacuum created by an ascending plunder, it permits gasoline entry into the pump chamber and, when seated, to force it out via a different passage through the atomizers. but i could not fathom the purpose of the needle and seat valve.

only later, after a bit of research, was it revealed to me (and i'm not certain that it's valid) that it is to prevent unwelcome and untimely "sloshing" of fuel from the chamber up through the passageway, out the atomizers and into the fuel/air mixture. something about inertia, and violent and/or excessive motion of the automobile, i think.
 
It's like a fuel pump that also has two one way valves. The two valves "point" in the same direction so fuel flows one way (towards the squirt nozzles). Without the second valve the fuel could just move back and forth in the passageway.
 
hueyhoolihan said:
my understanding is similar and along the same lines...

while i had my 94 disassembled i became curious as to why there were two mechanisms serving as what could be described as check valves and why they were different.

it was clear that the ball was necessary. for when unseated by the vacuum created by an ascending plunder, it permits gasoline entry into the pump chamber and, when seated, to force it out via a different passage through the atomizers. but i could not fathom the purpose of the needle and seat valve.

only later, after a bit of research, was it revealed to me (and i'm not certain that it's valid) that it is to prevent unwelcome and untimely "sloshing" of fuel from the chamber up through the passageway, out the atomizers and into the fuel/air mixture. something about inertia, and violent and/or excessive motion of the automobile, i think.
Click to expand...

Huey, methinks you think too much.
 
Mart said:
It's like a fuel pump that also has two one way valves. The two valves "point" in the same direction so fuel flows one way (towards the squirt nozzles). Without the second valve the fuel could just move back and forth in the passageway.
Click to expand...

yes, much more reasonable...

sort of like a revolving door at a hotel. as one enters, you and the outside air in the chamber is moved inside. and the inside air and anyone in the opposite chamber is moved outside....makes more sense. :)
 
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