New Mechanical Fuel Pump instalation trouble

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JeepNorris
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New Mechanical Fuel Pump instalation trouble

Post by JeepNorris »

82 cherokee AMC 360
Trying to install new stock mechanical fuel pump but can't get the bastard in enough to be flush. The inlet tube on the new pump is very close to hitting the PS bracket to allow the pump to seat properly on the engine.

The old one came out fine. I have read that the motor should be TDC (the spot where cam shaft would fight ya less) and I set it there before removing the old pump.

Don't really want to remove the power steering pump and bracket. Any other tips on how to wiggle this biotch on?

Thanks
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Stuka
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Re: New Mechanical Fuel Pump instalation trouble

Post by Stuka »

Is the new pump the same size and design as the one you took out? I have seen once before where a pump that mechanically would bolt up, but would not fit because the design was slightly different.

PS: I fixed the typo for you in your post, and reward a small part.
2017 JKU Rubicon
Pevious Jeeps: 1981 J10, 1975 Cherokee, 2008 JK, 2005 KJ, 1989 XJ

PossumJr
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Re: New Mechanical Fuel Pump instalation trouble

Post by PossumJr »

Outside of pump dimensions as Stuka brings up, are you getting the lever properly positioned in regards to the pump eccentric? Changed mine out with a Delphi unit, didn't pay any attention to if the engine was at TDC or not, but other than having to fight the spring some as the lever was depressed it went right on for me.
1979 J10, 360/QT
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tgreese
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Re: New Mechanical Fuel Pump instalation trouble

Post by tgreese »

Maybe not relevant, but there are two different pump designs. The early pump has the threaded outlet pointing down, and the later pump has the threaded outlet pointing up.

Early -

Image

Late -

Image

Note that on the early pump, the arm goes below the eccentric, while the later pump the arm goes above the eccentric. Don't know if it's possible, but make sure you do not have the arm positioned on the wrong side of the eccentric.

I've installed these many times, and I've never bothered to put the engine at TDC or whatever. Just put the arm up against the eccentric and compress the internal spring in the pump to make it sit flat against the block.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
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tgreese
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Re: New Mechanical Fuel Pump instalation trouble

Post by tgreese »

Also, an '82 uses the late-style pump from the factory.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.

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JeepNorris
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Re: New Mechanical Fuel Pump instalation trouble

Post by JeepNorris »

Thanks everyone for the responses.

I have the late version pump that BJ's Off-road sells: https://www.bjsoffroad.com/Fuel-Pump-AM ... p_552.html
Old n New Pump.jpg
My issue is the in-bound rigid port is hitting the PS pump bracket
Screenshot_20210708-111239_Gallery.jpg
not allowing the fuel pump to align with the second bolt hole (furthest away from the radiator) so the entire pump isn't vertical but skewed with the top leaning towards the front of the vehicle like 10 degrees or so.
20210708_110613.jpg
Also, here is a view into the block, my assumption is that the arm on the new pump was to go below the shaft. After reading this post that was true for the early style pump and not the late style. So we know for sure the late version is to be placed Above?
Screenshot_20210708-111134_Gallery.jpg
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Topic author
JeepNorris
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Joined: Wed Dec 02, 2020 7:22 am

Re: New Mechanical Fuel Pump instalation trouble

Post by JeepNorris »

Got it on. The trick I found was to align the rear bolt first. Assuming the advice given that the pump arm is to reside above the eccentric is accurate, it went on a lot easier and the conflict with the PS pump bracket up top was resolved and no longer binding.

Is there anyway to tell before firing it up if the arm is in fact above eccentric shaft?

Obviously - once its' installed you can't see but it felt like it went above.
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Stuka
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Re: New Mechanical Fuel Pump instalation trouble

Post by Stuka »

It will not bolt up if the arm is in the wrong position. eg: below the cam instead of above.
2017 JKU Rubicon
Pevious Jeeps: 1981 J10, 1975 Cherokee, 2008 JK, 2005 KJ, 1989 XJ

Topic author
JeepNorris
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Re: New Mechanical Fuel Pump instalation trouble

Post by JeepNorris »

Awesome, so it sounds like its on right.

Thanks again!

Topic author
JeepNorris
Posts: 17
Joined: Wed Dec 02, 2020 7:22 am

Re: New Mechanical Fuel Pump instalation trouble

Post by JeepNorris »

Quick follow up, do I need to prime the new pump?
Fyi...I've just completed Edelbrock EFi system with surge sump tank so there is no longer a carb.
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tgreese
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Re: New Mechanical Fuel Pump instalation trouble

Post by tgreese »

No, no priming needed.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.

Topic author
JeepNorris
Posts: 17
Joined: Wed Dec 02, 2020 7:22 am

Re: New Mechanical Fuel Pump instalation trouble

Post by JeepNorris »

thanks
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tgreese
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Re: New Mechanical Fuel Pump instalation trouble

Post by tgreese »

NP. Glad we could help.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
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