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Bakelite Fuel Pump Spacer Thickness


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Short version


What is the thickness of the bakelite mechanical fuel pump spacer for a L16 motor in a 1971 510 Wagon?


Long version

Before I put on my 3rd fuel pump, I want to make sure that the fuel pump spacer is the right thickness.  The first pump (bought on Amazon, was lazy) broke at the casting where the steel pivot rod holds the pump actuator arm.  Thought it was a fluke so I installed a second pump from Autozone, different brand and the actuator arm snapped in half right at the pivot point where there is the least amount of material.  Thank the Datsun gods that nothing fell into the engine and got chewed up. 


My bakelite spacer is 3/8 thick.  I just made a 1/8" thick aluminum spacer that I am going to put on pump #3 in addition to the bakelite spacer to see if that helps.  I remember thinking that the pump didn't have much travel when installed and I am guessing that the actuator arm is bottoming out causing it to snap off.  The cam eccentric seems to be fine.


I bought the car not too long ago and it wasn't running.  There was no fuel pump on it so I have nothing to compare it to.  Thanks for any help and suggestions.  

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I did install it under the ecentric the frist time and it mad e an awful noise. I now take off the valve cover and make sure it rides on it. Got a free pump from warranty and made a 1/8" spacer last night to put on in addition to the bakelite spacer. Hopefully its enough to prevent the actuator arm from bottoming out and breaking. Just need to get my car home. Will order a nissan pump then.

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Damn, had to get towed home.  Made it halfway home when the car died.  Kept cutting off like it was running out of gas.  I'm almost 100% sure that it is the fuel pump. 


Let me back up a bit here.  Got my new autozone pump and installed it with my homemade spacer and the bakelite one.  The pump actuator arm didn't touch the cam eccentric.  Removed my homemade spacer and reinstalled.  Now the actuator arm moved when I turned the engine over and it still had play in it meaning that it wasn't bottoming out.. Had high hopes for this one because the other pumps had no play.  Broke down about 7 miles from home.  Will take it apart this weekend and report back.


Options and thoughts

1.  Autozone fuel pumps might suck and they just randomly break

2.  My cam Eccentric is too big but Doctor 510 said they are all the same and I believe him

3.  I put an advert for a new or used oem Nissan pump like datzenmike said to do

4.  Switch over to a low pressure electric fuel pump

5.  Park the car and never drive it again, just kidding.  I love thing, just wish I could get it going RELIABLY.

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Put a hose on the outlet side and direct into a suitable container. Crank the engine over with the coil wire off so it won't start. What you should see are strong surges of fuel into the pail.


No fuel could be ...

The needle valve on the carb sticking

The float sticking in the up position

Fuel filter clogged

Fuel line clogged

Fuel tank empty or low.

Fuel tank not vented.

and it could be the pump.

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Happy Thanksgiving everyone. There's a calm before the deep frying storm so I figured I would tear into this fuel issue. To my pleasant surprise and confusion, the fuel pump was not broken.appy Thanksgiving everyone. There's a calm before the deep frying storm so I figured I would tear into this fuel issue. To my pleasant surprise and confusion, the fuel pump was not broken. Heres a pic of my broken amazon pump. You can see where the castings holding the steel dowel broke.



image upload


Disconnected the fuel line to the carb and manually operated the pump. Gas spurted out but seemed weak. Increased the fuel pressure on the regulator and got it to shoot out harder.


I have come to the conclusion that these fuel pumps are all a little different. Comparing the arm lenght and angle on two different pumps and they are not the same, hence the broken arms. Like I said in a earlier post, the pump actually had play in it when installed but I think the stroke ws not enough to overcome the pressure regulator and kept running out of gas. While broken down on the side of the road, I could see that the fuel in the fuel filter was barely touching the element and qas wicking up gas into the carb.


Here's an overall pic




post a picture


Charging up my battery. Will give it another go. Time for some deep fryin.

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All right. Thanks to everyone for the input. I eliminated the weber fuel pressure regulator (I put it on because a mechanical pump was putting out 7 psi) and replaced the only fuel line that I haven't replaced yet, the one from the metal line up to the filter. Fuel in the fuel filter seems to be at a higher level. I have a used nissan filter, a new fuel filter and my toolbox in the back in case something goes wrong but I think we got it. Thanks again to everyone.

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