Wiring A K-Jet FI Brain, Need Wiring Diagram or Photos.......Help Options

[Jeffs9146]

I am preparing to fire up my 3.0 and I have not been able to find anything that tells me where each of the wires goes on the harness and how it ties into the engine harness as well as the 914-6 relay board!

Any help is greatly appreciated!!

PS: It is a 1983 sc motor.

[SLITS]

As stated, the brain is a standalone for controlling the frequency valve only. It has no other function. On a 911, it resides under the passenger seat.

Just as a WUR will bleed off pressure to the return line, so does the frequency valve. If my engine wasn't on the 3rd tier of pallet racking, I would shoot an image.

I do not know the internal construction of the frequency valve, but assume it works like an on/off bleed port, bleeding pressure to the return line to the tank. I do know that Bosch describes it function in terms of a "Percentage Duty Cycle". The O2 sensor, sniffing the exhaust, determines if the mixture is optimum, lean or rich. This signal goes to the brain and determines the "Percentage Duty Cycle" of the frequency valve.

CIS injectors are mechanical and can only vary the amount of fuel injected by varying the pressure they see. There is no timed open dwell time like an electrical injector.

I doubt you would find a useable pin to activate it on a 914/6 or 914/4 relay board. If I were hooking it up, I would merely run the wires for the O2 sensor and the frequency valve connector thru the center tunnel to the brain. Switched power for the circuit can come from the fuse panel.

Want to know more? Buy and read the book "Bosch Fuel Injection & Engine Management" by Charles O. Probst, SAE. It describes all the systems, testing, etc.

For wiring, you are going to have to pick up a diagram for a 911 and trace it out.