Okay, I was told that I could test the rear injectors without taking the intake plenum off of my '92 SE. There are four prongs on the plug and I don't know which one is the ground. I know they all share the same ground, but which one is it? I tried to do trial and error and the lower left prong gives me readings that are all around 12 but I don't know if that is an accurate reading of the injector itself. Please help if you know anything about this. My engine idles a little rough and the exhaust is really hot and pinging, which I am told is a sign of running lean. Any suggestions?

 

If you are looking at the connector that this tab thing is at the bottom then you are right and left lower prong is the ground. 12 ohms is good resistanse for injectors. Though I heard ppl here saying that correct resistanse doesn't guarantie that injectors are ok...

 

Thanks for the info, I tested them and they are okay. Now I just have to find out what else is wrong with my car to make it idle so funny.