Intimidater38

Im new to the 240 scene but i have i would say basic knowledge. I bought a 91 240sx and ts been sitting for about 4-5 years. The pump is toast but i was wondering if the sending unit was salvageable. I pluged it in and it only reads about 1/2 tank. Does anybody know how to ohm out the sending unit? Where can i find on thats not gonna break me or whats a good replacement or alternative step?

Croustibat

I have never head of them going bad. The sending unit is the floater on the arm, on the pump hanger and is not part of the pump. You do not need to change it when changing the pump.

Intimidater38

I know i need a new pump but the sending unit wont read past 1/2 tank. Can you calibrate it or is the unit not the problem. Thanks for the feedback.

KoukiMonsta

sending unit is super simple. you said the word 'ohm' so I assume you know they are variable resistors.

get the FSM - type '240sx edge serivice manual' into google and you can find pdf. look in electrical section.

pull out the sending unit and move the arm by hand and check resistance.

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@UpshiftEngineering

Intimidater38

Thanks will definitely need to check that out.

Intimidater38

I checked it. The sending unit is bad. Some of the marks on the circuit board that the float is one have worn off. Does anyone know where to find a replacement piece or a whole sending unit? Anyone know a good direction to go in with it? Thanks

KoukiMonsta

try and clean the contacts with 0000 steel wool. But if they are worn down/gone you probably need to replace it.

I've never looked into a new one. What do the auto parts stores have? Maybe the resistor part is the same as used in other 90's Nissans, could try junkyard for them. altimas are everywhere,

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@UpshiftEngineering

Intimidater38

I can't find a physical replacement one specifically for a 240sx. Many that look like it but for other cars and im not sure if they will work. Might how to go check them out.