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Discussion Starter #1
Hello everyone!!

Yesterday my engine suddenly stopped. I realized that fuel lines had no pressure. The crane picked me up. I took out the fuel pump, pushrod was stuck. When I took out it I installed my old OEM fuel pump but it looks like that it's broken too, still without fuel pressure.

I was wondering if the pushrod is not working properly, I don't know if there is a problem with camshaft, maybe is not pushing the pushrod enough. I run the starter and I can see the slow movement of the fuel pump arm.

¿Can you help me? I leave you a video.

https://youtu.be/axfHffpR6FU

Thanks!!
 

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That looks like very weak pumping action. I tell you what, I'll trade you my '71 with a fuel pump problem for your '68 with a fuel pump problem!
 

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Discussion Starter #3
That looks like very weak pumping action. I tell you what, I'll trade you my '71 with a fuel pump problem for your '68 with a fuel pump problem!
I appreciate your offer <img src="http://www.chevelles.com/forums/images/smilies/biggrin.gif" border="0" alt="" title="Big Grin" class="inlineimg" />, but it's costing me blood and sweat to restore it, I never got rid of it 💪
 

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I can't say what the cause is for sure, could be a bad pump, could be sucking air somewhere between tank and pump on the inlet side due to bad rubber hose connections or pinhole/rust hole in steel line(ethanol eats older hoses), could be plugged in-tank pick-up filter sock on the sending unit, could be a problem with the fuel pump rod or cam lobe.

Everything good, it would shoot a 6" long 5/16" diameter slug of fuel clear over the front fender in that test you did....so there is definately a problem.
 

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I took out the fuel pump, pushrod was stuck.

Was it stuck because the tip was messed up on the inner part that runs on the camshaft ? If so it has probably worn the lobe off the cam. I just measured a stock camshaft and it looks like it moves the pushrod approximately .380" A little over 3/8" Not sure if you can measure how far yours is moving. Might give you an idea.
 

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Discussion Starter #6
It moves 3/8 approx. I can see the movement but I don't know if that's enough. The old pump that I have installed was working well few months ago, it should work but it doesn't, no pressure. How many seconds does it take for the pump to be full of fuel? (Starter running)

I have ordered a new mechanical pump, is the best way to know if camshaft love is not damaged, I hope that everything will be ok.

I'm going to install a backup electrical pump too, it's the second time car crane pick me up, now we are friends.
 

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It moves 3/8 approx. I can see the movement but I don't know if that's enough.
The camshaft I measured was brand new and that it about how far it was moving so I think that should be ok.
is the best way to know if camshaft lobe is not damaged
What did the tip of the pushrod look like ? If it was pretty smooth the cam should be ok.
 

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Discussion Starter #8
[/quote]
What did the tip of the pushrod look like ? If it was pretty smooth the cam should be ok.[/QUOTE]

It was brand new, no scratches or hit signals, but the pushrod was stuck, I think that it may be bent, probably not because it's a very thick steel bar.
 

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To long of a pushrod retainer bolt?? Check the sides of the pump rod
 

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When you installed the pump, what method did you use to hold the push rod up so you could install the pump?
Are there any wear, witness marks on the sides of the push rod?
 

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just put a new pump on, stick a hose on the suction end and drop it into a 1 gallon can full of gas and see what happens. jim
 

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What ever you do, DO NOT PUMP THE ARM UP AND DOWN! That arm only moves a little and when you pump it by hand you stress the rubber blatter...
 

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Do you have a hydraulic roller cam.?? If so, you might need a bronze tipped fuel pump rod to go on cam side..

Bob
 

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Discussion Starter #17
New fuel pump has arrived. Installed, everything goes well.

Old pump was broken too.

Thanks!!!!
 
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