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Mopar 318/ 360 Fuel Pump Problems

Posted: Mon Jul 14, 2014 3:36 pm
by Fastjeff
This little bug bit me at last. Here's the deal:

"Weird" stalling and misfire under load, usually while on plane or getting there. Gotta be "White Gook" (ethanol formed, unburnable crap) I assumed--all last year. Nope. The fuel pump wasn't putting out enough, and why? The cam that works the arm is screwed up.

The below photo shows what the thing looks like. The keyway shown wears a 'slot' through the key on the cam, and the darn thing rotates on the cam instead of working the fuel pump arm. The solution is a major rip down of the front of the motor, or an electric fuel pump. I've opted for the later and will be installing it next weekend (along with the required safety off oil pressure switch).

Jeff

Re: Mopar 318/ 360 Fuel Pump Problems

Posted: Fri Jul 18, 2014 3:04 pm
by ericinga
You know, that makes alot of sense.

I've been dealing with fuel supply issues. Occassionally, the motor will mysteriuously become starved for fuel after running for an hour or so. It has never really had full power or planed well. At full throttle, it won't rev higher than 3300 RPM. I've worked through the ignition system, carb install and tune-up.

There is a problem with tank debris that will be cured with time and filter changes. However, even a new fuel pump did not completely solve the supply problem.

I'm planning to stick a pressure gauge on it this weekend to determine the pump strengh. I'll also take the output line off and verify the flow rate into a quart jar.

Which pump and pressure switch are you installing?

Eric

Re: Mopar 318/ 360 Fuel Pump Problems

Posted: Tue Jul 22, 2014 5:45 am
by Fastjeff
I used an Airtex E8251 Universal that I bought from Amazon. (It's USCG approved.)

The safety (oil pressure) switch is a three pronged deal for a mid-80s Dodge V-8. (There's several different types. Go to Auto Zone and check out the photos on their computer.) Use the prongs opposite of each other on the switch (normally open). Finally, being anal, I used a relay to operate the fuel pump (instead of the contacts inside the safety switch). I ground the coil circuit of the relay to operate the pump, with 12 volts right off the battery. I also used 10 amp in-line fuse.

Jeff