Fuel Injector Test Block


The Jaguar Pre-HE V-12 engine signals injectors in banks of three. All 12 injectors are controlled by four signal wires from the amplifier. Testing the pulse duration of the fuel injectors via these signal wires is a necessary function whenever diagnosis of the air/fuel mixture is required.

My current method of either pulling off an injector plug, or piercing an injector signal wire was unacceptable. In addition there was no easy way of testing all four signal wires to determine if any variation in signal width existed.

While rebuilding my fuel injector harness a unique opportunity presented itself for me to install a fuel injector pulse width duration test block.



During the connection of the new fuel injector harness to the existing amplifier plug, I soldered a bridge to the signal wire. (Photographed below red arrow)



I identified all four signal wires and soldered wire bridges to them. The color of the wires identify which three injectors they control. (red arrows)



After identifying lengths, I soldered wire ends on the tips of the bridged wires. (red arrow)



I purchased a generic 4-connection test block at Radio Shack (electronics parts store in the US) and riveted the test block on the inner wheel well of the right fender. I connected the four signal wires to the block (blue arrow) and secured the wires with a clamp. (red arrow)



Pictured below is the wire from my pulse duration tested connected to one of the connections on the test block. (red arrow). Each connector represents a signal to one bank of 3 injectors.



The test block should be covered. The cover was sourced from Radio Shack, however it needed modification. I cut slots in the cover (red arrow) that would allow the test block (blue arrow) to fit into.


The original cover is way too big. You need to cut in half.



The cover (red arrow) should fit snugly around the test block. (blue arrow).




I drilled two mounting holes at the very top of the cover. (blue arrows)



The cover is installed over the test block.



I attached the cover with two self tapping screws.



Fuel injector pulse width duration signal test block complete.




 

 

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