The Stovebolt Site Forums The Shop Area Engine Shop Help me install my fuel pump correctly. Please.

Being new at most everything related to this truck, I simply unbolted the old non-functioning mechanical fuel pump on my 1965 230ci inline 6. A few minutes later I had my new fuel pump bolted onto the engine block. Simple, right?

Apparently not! I found out tonight that it just isn't pumping fuel. I put my finger over the intake side while cranking the engine and it doesn't have any suction.

I looked through the FSM but I think I need more help.

Anyone?

http://i618.photobucket.com/albums/...20Chevy%20C10/fuel%20pump/0721121717.jpg

First, check to see that the camshaft lobe that operates the pump isn't worn out. Remove the pump, and have someone tap the starter as you shine a bright light into the hole. There should be a noticeable high spot visible as the cam turns. If the shaft is round, or showing extreme wear, it's time to change the cam. It's also possible you've simply bought a non-functional new pump. Push the pump operating rod down against the workbench top and see if any vacuum is developed at the inlet port. It's either a bad cam or a bad pump, or possibly both, but that would be pretty unlikely!
Jerry

So I assume there is no special connection or way to position the fuel pump. Right? Originally, i assumed that if I bolted it onto the block correctly, then it should contact the cam and work.

This evening I'll pull it off the block and use a mirror to look inside to see if that cam looks rounded off. I kinda doubt that is the case since the engine only has 88k miles. I'll post an update.
Thanks

Straight 6-cylinder pumps go on with the in and out connections on top...which is 'upside-down' compared to a V-8. Ask me how I know.

cm

I'm working on a Jeep CJ5 with a 304 V8 and had the same problem... No fuel to the pump... so I bought a new pump. Still, no fuel to the pump. To make a long story very short, yes, check the action of your pump. You can even manually push the pump lever to see if it's sucking with your finger over the inlet...
But my problem wasn't the pump... and by the way, I still have my old pump as a good spare!
For me, there was a rubber fuel line that was clamped well but in not that great of shape. Though it wasn't showing any leakage I guess it breathed, not allowing a good suction. Try drinking from a straw with a split in it...
I replaced the rubber line and it solved my problem.
2 cents worth...
Good luck,
Jerry W

First, thanks to all who took an interest in helping me solve this problem. I really appreciate it.


Jerry, you were right! I removed the fuel pump and it tested OK by hand. I could feel it suck at the inlet and I could make it suck gas out of a gas can by hand pumping the lever.

Here's a picture of the cam lobe.

And another picture.

It has a groove down the middle and after tapping the starter a few times, it appears to be round in the middle where it contacts the fuel pump.

Finally, I bolted the fuel pump back on and it will not pump gas and has no suction when I crank the motor.

The PO had hooked up an electric fuel pump and bypassed the mechanical. Now I know why. I had always assumed it was because the mechanical fuel pump went bad.

What all is involved in replacing that cam and should I consider just using an electric fuel pump instead? Does that cam have any other function?

the pump lobe just runs the pump .... you don't want to replace the cam, especially if you already have the electric pump

Bill

Thanks Bill. I guess it'd be a lot of work. Shucks, I guess I bought a $50 mechanical fuel pump for nothing.
The electric fuel pump I have is made for carburetors and has about 4 to 7psi if I recall correctly.
I'm kinda surprised that the lobe on that cam is rounded off with only 88k miles on the truck. It makes me wonder if it might have 188k or possibly my odometer cable broke at 88k and it has a lot more than that. Anyone ever see a fuel pump cam wear down with mileage of less than 100k?

depends how often the oil was changed, and on how long it was run low on oil

Bill

Seems like there is still enough to operate the pump.Did you install the pump in the right position ?


Tim

You asked if there is a "special connection", and mentioned "if I bolted it onto the block correctly, then it should contact the cam and work". I really know nothing about the 6 cylinder motors, but I assume there is a pushrod for the fuel pump? Is the pushrod present?

From all of my observation and reading, it appears that the inline 6 engines have a fuel pump that operates by a cam that presses on the lever on the back of the fuel pump. There is no connecting rod (as I've been told exist on V8s.) I think the pump is installed correctly, just wasn't sure that it was until I pulled it all apart, tested it, and reassembled everything.

Here's a picture of the pump showing the lever.

That lobe looks ok. From your photo it is hard to tell if the lobe is rounded or not. I took the oil pan off a 261 last night and the pump lobe looked just like that. I had to take a closer look to see the lobe was indeed good to go.

Yes, the V8s use the pushrod. Thus my disclaimer about not being familiar with the inline 6. Always good to learn something new.

Drum roll...
Was this resolved?
Jerry