Discussion: NBS Injector Swap How to

bgray

Stylish Canadian
Mar 17, 2012
3,052
95
48
37
Onterrible, Canada
Write up For Swappign Injectors on a NBS. Most common swap for MArine inejctors for running heads and cam, or big cam
Tools
Small screw driver
Torx Bits
10mm Socket

Supplies
Sythetic Lube

First, You need to remvoe the engine cover, and unplug all of the Injector Wires. Remeber to disconnect your battery, I like to use quick disconnects like this that save your radio settings, but un ground the battery...


Here are my new 31-32 lb inejctors. Out of a 8.1L truck, bolt right up. Even the 42# marines looks about the same. Come with new orings

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To disconnect the harnass from each injector you simply need to remove the grey palstic locks that run length wise, and then depress a small black tab to unlock the clip and pull off injector...

Your next step is to Release all of the system pressure that is built up in the lines. On the Pass. side there is a small air valve and cap..unscrew the cap, and use a small screw driver, with a rag underneath, to relase pressure from the FI system. Careful, full will spray, I recommend a good size rag and safety glasses for sure...

dominica169.jpg


On the Passenger side Make sure to disconnect the Vaccum for the Fuel Pressure Regulator

dominica170.jpg


On the Main fuel rails on both sides are other fuel lines that conenct in. One on both passenger(one Tube) and driver(2 tubes) sides. Using a small Torx Bit, Unscrew the hold down plates, and pull the tubes out...again fuel will come out, and becareful to not lose the orings.
driver Side
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Pass Side
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On the Driver side there is a bracket that must be removed that bolts under the fuel rail hold down...this bracket supports the two other driver side fuel lines...
dominica173.jpg



Remove the Fuel Rail 10mm screws on both side..Again..there is fuel in the rails...just be careful

dominica173.jpg

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Now that the rails are out, Remove the small metal clips on the bottom of the injectors where they are attahced to the fuel rail and remove all 8 injectors. I used a twisting and upward motion to remove them...mind the orings etc


dominica176.jpg


To install the new inejctors, take a small amount of lube and lube ONLY THE ORING...be very careful do not get anywhere near the spray outputs...then simply push the inejctors into the rails

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Reisntall the metal clips

Now reinstall everything....make sure the injectors are seated properly into the motor, and reattached fuel rail brackets and 10mm screws, vaccum line, plug in injectors, put on clip lock and tie up all other lose ends.

The truck will need a tune to run properly..i dont suggest running the car due to a risk of Fuel Washing the cylinders...ITR is 28.0 for my cam and tune
 
Last edited:

Blitzbody37

New Member
Mar 21, 2012
39
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0
after you swap the injectors, do you just turn on the truck to get the fuel pressure back up? i need to replace just one of mine. thanks
 

bgray

Stylish Canadian
Mar 17, 2012
3,052
95
48
37
Onterrible, Canada
after you swap the injectors, do you just turn on the truck to get the fuel pressure back up? i need to replace just one of mine. thanks


Yes once you button it back up, cycle the keys a few times, release pressure(and air) in the rail again, then cycle the key a few times more and it'll start