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Moparaholic
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Discussion Starter #1
Hello I am sorry I have not been online here in awhile. Very busy with life. I recently decided to pull my 87 5Th avenue (318) out and get some maintenance things done with it. I got a Tune up, Tires, Shocks, Wiper bushings etc. I also was having an issue that started last year before I put the car away. When the car sits for a few days it didn't want to start. If you got the car running with starting fluid it was ok. If it was running it would restart with no issue. I believed it could be a small fuel line leak that was allowing the fuel lines to lose prime.

I took the car to a buddy and Mopar Mechanic. He was a service manager of a dealer than closed during the restructuring. I also noticed a fuel odor. The odor seemed to be coming from the front area around the charcoal canister area. My buddy checked the fuel lines multiple times found no leak. My car has never been in the snow so it has very little corrosion. We then visually checked the fuel vapor line hoses. Everything was intact. Car was running good until yesterday. The car fired up ok. I drove it a short distance, shut the car off and it was ok. Came back in about 15 minutes fired it up ok. Then it stalled. Again ran a bit stalled. I would get it running, it would start running like crap, then out. Finally it wouldn't start. No start with starting fluid or anything. FInally my buddy came over and we got it running with a good treatment of starting fluid. Got it home and parked it. We hypothesized a fuel pump.

I ordered a Mopar Performance fuel pump from Jegs. It said for all A/LA Engines. But I have some concerns. The pump has 1/4 inch fittings, according to the FSM my car has 5/16th. Also the pressure is 8.5 PSI. The FSM says 5.75 - 7.0 psi.

Will this pump work? Anything else I maybe missing?
 

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Super Moderator
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If this is a carbed vehicle, both fuel pressures are fine, close enough. If EFI, it's the wrong pump.

I know the EFI pumps have a 5/16" supply and a 1/4" return line. I don't know the sizes for carbed vehicles.
 

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Premium Member
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The 8.5psi is the Throttle body injection "carb", the actual carburetor is what you should have, which is what the manual states, no greater than 7.0psi. Another reason the fittings are the wrong size. I would not use the pump without a pressure regulator, and then you are still going to need some fitting adapters, so have them try to get the correct pump.
 

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Moparaholic
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Discussion Starter #4
according to jegs that pump is ONLY FOR carburetor/mechanical pumps only. Absolutely not for an application for EFI.
 

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I would go with the max pressure for the FSM, being 7.0psi. Anything above that will overcome the float in the carb, which will give you problems. TBI "carbs" use 7.5-11psi. That kind of answers the whole debate for me. Why not a stock mechanical pump? You can get lifetime guarantees on them and are usually cheap enough.
 

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Moparaholic
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Discussion Starter #6
The reason... I wanted a Mopar Pump. Some of the aftermarket pumps tend to be questionable according to my research. New Old Stock is out on the 5th. So it was Mopar Performance stuff or aftermarket. The MP was actually better priced than some of the DIRECT swap out aftermarket parts.
 

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I've used the Airtex fuel pumps on the small block Mopars over the years and never had one fail. Bought them at Autozone for around $20 or so.
 

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Is this a 2 or 3 port fuel filter? The 3 port had a fuel tank return port that vastly reduced fuel pressure delivery the the carburetor. If a 2 port filter is used in place of a 3 port, the delivery pressure will be way too high.
It may be best to actually try to gently blow through the vapor and return lines as I have seen them rust shut on the inside of the steel tubing while looking fine on the outside.
 

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Moparaholic
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Discussion Starter #9
ImperialCrown said:
Is this a 2 or 3 port fuel filter? The 3 port had a fuel tank return port that vastly reduced fuel pressure delivery the the carburetor. If a 2 port filter is used in place of a 3 port, the delivery pressure will be way too high.
It may be best to actually try to gently blow through the vapor and return lines as I have seen them rust shut on the inside of the steel tubing while looking fine on the outside.
3 Port Filter. Brand new. My buddy who came help me when I broke down actually did blow through a few vapor lines. Saw no issues.
 

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That's a touch of information that would change things. 3 lines, that is.
 
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