AMC V8 Engine Repair and Modifications

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New fuel pump failure

Printed From: TheAMCForum.com
Category: The Garage
Forum Name: AMC V8 Engine Repair and Modifications
Forum Description: AMC-made V8 engine mechanical, ignition and fuel from basic repair to high-perf modifications
URL: https://theamcforum.com/forum/forum_posts.asp?TID=92505
Printed Date: Apr/19/2024 at 8:52pm
Software Version: Web Wiz Forums 12.03 - http://www.webwizforums.com

Topic: New fuel pump failure

Posted By: WallyMax69
Subject: New fuel pump failure
Date Posted: Feb/13/2018 at 3:53pm

So exasperated -

Just tried to start the rebuilt motor and tracked it down to fuel pump.

Disassembly revealed that the shaft connected to the diaphragm was never connected to the rocker pump arm. Haven't removed the arm yet (must drive out wrist pin) but I am guessing that during factory assembly, they had it turned sideways rather than perpendicular as they installed the arm - the hook, or the "eye" rather, was turned sideways so the point (tab?) never made into the slot of the diaphragm shaft.

First clue was that the pump was very easy to operate by hand (too bad I didn't notice during installation weeks/months ago...

So a question -

I can reasonably assume factory assembly failure - I mean I couldn't have dislodged it during installation?

the "eye" on the diaphragm shaft is clean - no damage or trauma.

Just want to gauge how much steam to let off on my parts guy...

- W

Replies:

Posted By: mmaher94087
Date Posted: Feb/13/2018 at 5:17pm

Not the 'parts guy'. Akin to shooting the currier. Present the problem and ask him to correct the manufacturing defect.

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Mike

Posted By: WallyMax69
Date Posted: Feb/13/2018 at 5:59pm

So we took it apart in an attempt to soldier on vs. waiting several days for a replacement. The diaphragm shaft has an eye on it that receives a hook on the end of the pump arm. This arm is actually two-piece with a pivot point where the wrist pin is. Not only was the hook out of the eye, this whole piece was assembled backwards so the hook never had a chance of holding onto the eye. It has a slight "nub" if you will, but there was no chance that it could work backwards like that.

We reassembled it after a small struggle, and it seems not to work still. Gonna give it back and try another one from a different parts store. I hope it is not the same make/supplier...

Posted By: WallyMax69
Date Posted: Feb/14/2018 at 12:56pm

Got that pump from NAPA. Ordered another one from O'Reilly. It is identical.

Out of the box (before leaving the store) the pump arm does not have the proper resistance - sure enough, opened it up and the pump arm hook is NOT in the diaphragm shaft "eye".

Where do you guys get your fuel pumps?

This is ridiculous...