Fuel Sending Unit - Fuel Assembly

Does it have spark? And other questions...

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Fuel Sending Unit - Fuel Assembly

Postby wilkyflex » Mon Mar 18, 2019 12:14 pm

My 1992 Dodge D250 Diesel needs a new fuel assembly or I need to fix what I have.

I've been told that the old new fuel assembly that will work on this truck is a Carter P74699R
But the problem is that the new assembly is a 6 pin connector instead of the 4 pin on the old assembly.

The contacts on the sending unit are not touching the grid. I think I can fix this, but I will have to test with an Ohm meter. Do you know what Ohms it should be reading?
The other problem is about one of the two strainers. There's one strainer that is plastic and about 4" diameter and 1" thick. This obviously filters the fuel.

But there is another strainer on the inside of the assembly at the bottom. it's about 3-4" in diameter and has a 1" diameter hole in the center. And it's about 1/4" thick. It also has a rubber part that acts like a valve. I think it allows fuel to go one way. Anyway, I sprayed it with brake cleaner and it ruined the rubber flapper valve.

Can I use the pump without the smaller screen?
Is there a rubber piece I can buy somewhere to replace that one?

fuel screw!!!!
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Re: Fuel Sending Unit - Fuel Assembly

Postby PToombs » Mon Mar 18, 2019 4:21 pm

Just bend the arm so it touches the windings again. To test use an analog multitester, as the arm goes up the needle should rise smoothly with no stopping or gaps. If it stops a winding may be burned up.

IIRC the rubber part is a check valve, it lets fuel into the container from the tank, and holds fuel in that returns from the IP so the container keeps fuel in it. It's been a while since I had mine out but I'm pretty sure that's how it works.

Just enough power to break everything behind the crankshaft.
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Re: Fuel Sending Unit - Fuel Assembly

Postby Begle1 » Sun Mar 31, 2019 5:21 pm

Something I've learned the hard way is that, while testing fuel level senders, you want to do it wet. They tend to work much better when submerged in fuel than when dry and dusty.
1990 D-250 Regular Cab: Tweaked injection pump, built transmission, a cataclysmic charlie foxtrot of electronics, the most intense street-ran water injection system in the country, and some more unique stuff.
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