Good evening, I was wondering if anyone else has had this problem. The car is an 89 760 Turbo. Has been running fine until two days ago. Now running on 3 cylinders.
I have checked everything and I have found that the number 2 injector is getting no power through the wiring harnes. All other cylinders are firing. Would this be a control unit (ECU) problem, or if that were to go out would all the injectors not fire? The other three are fine and getting power.

Any help would be appreciated. Thenk you.
quinn42269@aol.com

I just wanted to thank everyone who responded. It actually was the Injector Ballast Resistor. A wire had come off. I cut and resoldered the connections and it ran perfectly.
Unfortunatley on the way home that night on the expressway, I was stopped in traffic and was rear ended by a mid sized going about 55 MPH. No seatbelt and I walked away. Something to be said for that car. It took a major impact and was smashed between two vehicles, and I was still able to walk away. The car is totalled though.

Thanks for the help anyway.

With the ignition key on each injector plug should have a common source 12 volts on one pin and zero on the other. If one plug is missing the 12 volts then it's a wireing problem.

Power to the injectors comes through ballast resistors, mounted near the battery. If wiring to one of the resistors has broken, the injector will not get power.
Ground is through the FI computer; all injectors are in parallel.

If I understand this correctly, all injectors are powered all of the time with the voltage being reduced by ballast resistors. They actually fire when the computer supplies ground. Is it a single ground or four grounds? I have actually heard than many cars fire injectors in pairs or even all together without a great deal of concern about timing. Is that the case here? If they fire together, the poster's problem HAS to be the ground wires or the ballast resistor connections (or a bad resistor itself). You know, if the power is common (which it is), seems like only one resistor would be required. I'm still learning this car.

Thanks for that info, I didn't even think about that. So there is one ballast resistor for each injector? So there are 4 separate resistors mounted by the battery?

Correct; in a bundle.
http://69.0.158.19/live/C103527375OES.JPG

Thanks, I'll give the ballast resistor problem a try.

I'll let you know what happens. Thanks again.

Had this happen to mine, in my case connection looked OK but oxidation at the ballast resistor was the problem.

Hopefully someone with more knowledge than I possess will respond, but until they do....

It is my understanding that all of the injectors respond to the same pulse and that if one of them is not pulsing it could well be a wiring/connector/injector problem. While I do not own one it would seem that this would be a good time for a noid light to check for voltage at all the connectors. Lacking one of those perhaps a meter will work in its place.

You might not be getting voltage to the injector which would be reason to work back starting at the connector. Or you might have voltage and the injector is not pulsing.

Again I wish I could be more help, but perhaps chasing it with limited information might be enough in this case. Good luck.

Randy