Fuel pump rod not moving?

[farkle1989]

I have a single port 1500 that was running fine. I started the car warm, it ran for about 20 seconds and died. No fuel, so I stupidly replaced the fuel pump with one I had in my spares for my manx buggy which has an alternator with the shorter rod. So I ruined the pump. I went and got the correct pump but still no fuel. It appears that the pump rod isn't moving when I crank the engine. How much should it go up and down anyway? Don't know the next step and can't find anything on forums about no rod movement. I'd appreciate any help. Feeling pretty dumb right now.

[farkle1989]

P.S. The distributor drive appears and turns fine upon inspection through fuel pump hole. Thanks

[Glenn]

The rod rides on a ramp on the distributor drive. I doubt the rod is not moving. Make sure you have the correct rod/pump pair.

Alternator pump uses the 100mm rod and the generator pump uses the 108mm rod. (corrected)
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Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"

Member #1009

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[johnR]

Hey, Glenn. Shouldn't that be the other way around? Alternator fuel pump rod is shorter, right?

[Glenn]

You are correct. The Generator uses the 108mm rod and the Alternator uses the 100mm rod.

My source, was wrong.

Thanks
_________________
Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"

Member #1009

#BlueSquare

[Cusser]

Give Glenn a break, he's correct 99.99% of the time...

I also doubt that the pushrod is not moving....I'm assuming that the plastic pushrod housing is OK...and pushrod is facing correct way...
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1970 VW (owned since 1972) and 1971 VW Convertible (owned since 1976), second owner of each. The '71 now has the 1835 engine, swapped from the '70. Second owner of each. 1988 Mazda B2200 truck, 1998 Frontier, 2014 Yukon, 2004 Frontier King Cab. All manual transmission except for the Yukon. http://www.thesamba.com/vw/forum/album_page.php?pic_id=335294 http://www.thesamba.com/vw/forum/album_page.php?pic_id=335297

[johnR]

Oh, I know! I have learned a ton from Glenn and you and all the good folks here in the last few weeks. I just thought I should point that out so somebody doesn't destroy a new fuel pump at some point.

[Glenn]

[farkle1989]

Thanks guys, I will recheck if the rod is moving. The rod is installed correctly.

[vwpackrat]

You can use whatever type of fuel pump you want as long as you use the corresponding fuel pump rod length regardless of what you might think it is alternator type, etc....... The easy way to check this is when looking at the underside of the fuel pump the little "foot" that the pump rod pushes in if it is sticking out past the the bottom of the fuel pump base you need the short rod.............if the little "foot" is recessed up inside the fuel pump base you need the long one.
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62 Convertible Bug
67 Westfalia

[h20rider]

On a new rebuild (I did not do), my manual fuel pump does not seem to be functioning.
My diagnostic steps so far:
1) removed the fuel pump and greased it
2) observed the pushrod moves up and down…maybe 2 mm when engine hand cranked
3) removed the push rod… straight and in pristine condition
4)removed the phenolic insert….also in great condition
5)used an endoscope to check the distributor gear action…all good there
6) observed the rotation of what I assume should be a cam for the pushrod …simply looks like a rotating disk, but must have some effect since the pushrod travels up and down somewhat.

Still no gas being pumped.
Any other ideas?
Given that the distributor drive looks fine, I may just cap the manual pump and go to an electric.
Thoughts?

[Busstom]

Are you estimating "2 mm" of stroke on that pushrod? Because 2 mm is barely a 16th of an inch, and that's not nearly enough to stroke a fuel pump. I can't recall exactly, but the stroke is more like a 1/4" or more, which is like 6 mm or more.

Also, yes, there's a lobe on the distributor drive shaft that oscillates up and down with rotation, one complete up/down stroke per rotation.

But all is not lost; if you truly are getting only 2 mm stroke, you can easily replace the shaft, there's a basic procedure with some do's and dont's.
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My name's Steve and it's pronounced "Bust 'em" (cuz people think I'm Tom) 😏

[h20rider]

I thought about the pushrod length, but the travel would still be mediocre. It seems that the cam is barely a cam at all. I shudder to think of tearing the motor down to replace the cam.
Of course, I’d rather (mildly) have stuck with the manual pump, but I suppose I will need to go electric.

[Busstom]

No, you don't have to tear it down, the fuel pump drive lobe is part of the distributor drive shaft, the only thing you have to remove is the distributor (and the fuel pump, of course) to change the shaft. I'm not talking about the pushrod, I'm talking about the distributor drive shaft.

Here's what you're looking at... (pic courtesy of SlalomVan)

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My name's Steve and it's pronounced "Bust 'em" (cuz people think I'm Tom) 😏

[ashman40]

H20rider, three things for you to check:

Do you have a generator or alternator style fuel pump? Look at the moving foot from the underside of the pump. If it extends below the base of the pump it is an alternator style pump. If it is flush or recessed into the pump body it is a generator style pump. See the pic below.




What is the length of your pump push rod? 100mm = alternator, 108mm = generator. Are you running the correct push rod for your pump style?

When you measured the pump push rod travel did you do this over 2 complete rotations of the crank pulley? The distributor drive gear rotates once (360deg) for each 2 rotations (720deg) of the crank. If you only rotated the crank pulley 1 rotation you may not have measured the full stroke length/cam travel.

_________________
AshMan40
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'67 Beetle #1 {project car that never made it to the road }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!}

[Cusser]

I've observed where someone bought a "new" VW and it had a 108mm pushrod and a slanted fuel pump, and it bent the pushrod but did not break the plastic stand.

I really can't see a 100mm pushrod damaging a non-slanted type pump which needed the 108mm pushrod, but the fuel pump wouldn't work correctly.
_________________
1970 VW (owned since 1972) and 1971 VW Convertible (owned since 1976), second owner of each. The '71 now has the 1835 engine, swapped from the '70. Second owner of each. 1988 Mazda B2200 truck, 1998 Frontier, 2014 Yukon, 2004 Frontier King Cab. All manual transmission except for the Yukon. http://www.thesamba.com/vw/forum/album_page.php?pic_id=335294 http://www.thesamba.com/vw/forum/album_page.php?pic_id=335297

[1966novacoupe]

Just a quick question about the fuel pump push rod. My 61 beetle will stall after the engine warms up [15 minutes of drive time]. The engine is NOT overheating, its barely warm. Wont restart until the engine gets cold.then the same scenario. Seems the fuel pump push rod is sticking in the Bakelite guide and fuel pump spacer. I removed the fuel pump and found the push rod up to the top of its travel and stuck in the Bakelite. I had to use a pair of pliers to remove the pushrod. Tried to remove the Bakelite but its not going to come out easy. Is the push rod lubed by an oil passage that may be plugged? I dressed the push rod with 1200 grit wet/dry and it slid all the in and moves easily. Should i replace both the push rod [108 mm] and Bakelite? Thanks for any info or advice.

[glutamodo]

Yes, the bakelite spacer is known for "gunking up" to the point where it can inhibit the travel of the pushrod. You need to remove the rod, then the spacer, and run a rat-tail file through the pushrod orifice a few times and then put them back in and try again.

The bakelite spacer can get glued into the case though. Sometimes they have be broken into several pieces to change them out.

As for lube, it's just the ambient spray of oil present from the camshaft timing gear.
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Andy T.


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[Zundfolge1432]

Bump

[ashman40]

Check the push rod movement when your engine is stone cold. Does it move freely up/down in the stand?

What can often happen is as the case heats/warms up and the stand will start to expand. This eventually constricts the push rod and prevents it from dropping back down freely.
The fix is to pull out the stand (maybe you can remove yours once the engine is cold) and sand down the OD of the long part of the stand that inserts into the case. Create enough space between the case opening and the long part of the stand so even when they heat up it will not constrict the push rod's movement.
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AshMan40
---------------------------
'67 Beetle #1 {project car that never made it to the road }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!}