Hello All,
I started my 87 GN yesterday and I noticed it had a bad miss. I checked spark to each cylinder and they each had a nice spark. Next I decided to check the injector signals. I pulled off each injector plug one by one and noticed that by unplugging injector #1 & #2 the engine idle would not change. Injector plugs #1 & #2 do have a good ground (Brown Wire), but there was no signal at the signal wires. I also tested the continuity of the signal wires from the ECM to the #1 & #2 plugs and they were fine.
Also, there are no codes.
Does anyone have any ideas or suggestions?
Thank's,
Henry
can you hear the #1 and/or #2 injectors ticking? Put a piece of light wood up to your ear and the other end on the injector and listen if you need to. You can also tell usually by just putting your finger on each one to see if they're turning off/on or just stuck in one state. You should definitely feel them pulsing on/off if they are operational.
Jay,
Thanks for the reply, but I figured out the problem. It seems that my adjustable fuel pressure regulator (1991 Model) went bad and was regulating over 60psi at idle. This began to drown the cylinders so bad that it fouled the spark plugs. I installed a spare Accufab adjustable regulator,new plugs and problem solved. As for the signal to the injectors, my digital voltmeter's battery was extremely low and I was getting an incorrect reading.