Hey Guys,

I've got a 93' W350 with the 5.9L 360 MFI, it was running perfectly fine and then the Check Engine light came on, when I got home I checked the Code and i got a 12, and 27 the Code 12 is said to be normal and I'm not really worried about it, but the Code 27 (Injector number # output driver circuit does not respond to the control signal. Check the affected circuit.) I don't know what do do about it, how do I know which is the affected injector? And I was told it could be the pressure regulator, but the fuel rail seems to have plenty pressure. I'm guessing it's the wiring harness, because I never replaced it when I put in the new engine and some of the clips to the Injectors are broke. So any feed back as to how do find out what the affected Injected Injector would be, or what you think the problem might be?

 

Use a stethoscope on each injector until you find which one or more is not clicking/firing. A length of rubber tubing makes a good stethoscope if you put one end in your ear and the other end on each injector.

 

Thanks SEAL, I listened to each injector and it sounded like it was the number 3 Cylinder that was bad. You could hear it still but there was a significant difference in that one compared to the other ones. I ordered a new injector because it had a fairly good connection and I didnt think that was the problem. Do you think it's bad to just be replacing one injector vs. a full set of 8?

 

I replaced 1 of the 2 injectors in my TBI set-up instead of both. The only time I believe in replacing parts that are still working is when the labor involved is more than I am willing to do again. Personally I would run a can of Seafoam thru with a full tank of gas before I replaced any injectors.