I'm checking the continuity of the wires for my secondary fuel injectors, and I'm finding something that I cant' really figure out.

On both secondary injectors, I'm getting continuity between the 4W, 4X, and 4Y pins on my ecu, and the B/Y wire at the injector, but no continuity at all to the LG/ respective color, wires. According to the diagram I found on here, the B/Y wire should just be a ground, and the LG wires should be the ones coming from the ecu.

My secondaries don't work, so I checked continuity on the primary injectors, which work fine, and they are the same way. Is this correct? I'm not very good with electrical stuff, but this just doesn't make any sense to me.

Here's the diagram I'm looking at: https://www.rx7club.com/attachment.p...1&d=1227188446

Thanks a bunch.

 

4W to 4Z are pulled to ground by the ECU to activate each of their injectors.

The B/Y wire is power, not ground.

See this thread for a discussion of a simple injector testing procedure:

https://www.rx7club.com/showthread.p...condary+ground

 

Thanks. It sounds like I should get continuity between the lg wire and the ecu pin, but I don't. I guess my new question is if this means my harness is bad, why do I get the same readings on my primary injectors, when they both work fine?

 

So you are getting continuity between LG/R, LG/B, and LG/W and the corresponding ECU pin, but not for LG? This would imply that one of your secondaries is ok (the one attached to the LG/W wire). Or am I misunderstanding you?

 

I am not getting continuity between any of the lg wires and the ecu connector. I also checked the rear primary injector for comparison, and got no continuity between its lg wire and the ecu pin, as well.

I do read continuity between the B/Y wire and the 4W, 4Y, and 4Z pins but not the 4X. This holds with the B/Y wire for both secondary injectors and the rear primary injector.

 

I'm confused. How can you get continuity between, say, the B/W wire and the 4W pin and not get continuity between the LG/R wire and the same pin? The path from the B/W wire to this pin is through the LG/R wire?!!

Have you measured the resistance of the injectors?

 

Ok, sorry for not being clear. I have the injectors unplugged, and am sticking the probe for the multimeter into the plug on the harness that plugs into the injector. This why I'm confused why I'm getting continuity between the B/Y wire and the ecu, since it connects to the ecu through the lg wires. I am also not getting continuity between the lg wire on the injector plug and any of the pins in the connector that plugs into the ecu.

Does that clarify what's going on?

Here, maybe this picture can explain it better

 

you are either mistaken in your pinouts when doing the tests or your harness is shorted somewhere. The B/Y has power + when the EGI relay is engaged, which the ecu will supply a ground to, it floats otherwise. With the injectors and ecu unplugged there is no way to have continunity from the B/Y to the ecu connector. and the fact that you have no continuity from the ecu to the respective LG or LG/xx control side of the injector plug means it must be open or you are testing it wrong.

Where and how are you probing the ecu connector?

 

I unplugged the ecu and stuck the multimeter probe into the hole where the pin on the ecu would go. I'll check again next weekend, but I tried it four or five times since it didn't make any sense to me.