S14 Auto ECU Swap+ Fuel Pump Cut-off Switch

Articles, modifications, maintenance, DIY's, how-to's and general information for 240sx owners.
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adidas2go
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Joined: Thu Oct 18, 2007 9:49 am
Car: Cycle through all kinds of cars, trucks, motorcycles, and boats 🤙
Once upon a time: 1st turbo Altima Coupe
Location: Raleigh, NC

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To start

1. Remove or loosen the door sill. simply pry up and it will come free
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2. Next, remove the nut to left
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3. Simply pull the kick panel out of the way
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4. Now you have access to the ecu

5. Undo the bolt in the center to unplug the connector
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6. Now undo this bolt on the bracket
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7. Now pull out the ecu and replace with your new one (if your doing the auto ecu swap)

8. To do your cut off switch you need to expose the wires. Cut away the black loom like so
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9. Now, the wire you are looking for is the black wire with a purple stripe. NOTE* their are two black and purple wires* the one you want is the one by the the ecu connector bolt
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10. Just cut splice in your switch, and your done.

To clear up confusion:

*Cut off Switch*The wire you cut and spliced stops the current flow to the ecu, this in turn never trips the relay and the pump never turns on.

If you simply ran a switch to the ground on the pump you risk frying the pump or ecu!

Plus its easier to hide and a cleaner install.

Auto ECU swap myths and faq's:

This throws the check engine light. SMOG PEOPLE BE AWARE!

1. The car will run the same2. 95 ecu will work in any s143. 96-up will only work in 96-up4. Removes speed governor5. Higher rev limiter (7200rpm) The effects1. Cold start, it idles at 1500 then drops to 700 like normal after a few minutes2. The idle raises when you have the clutch in and move the shifter3. Throws trans code4. 95 ecu in 96-up throws o2 sensor code(although it still runs fine)5. Slightly better fuel economy

Article by: xweav32


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