Fuel Injection wiring

[zoneboy2]

Having a problem with the wiring a 73 240Z with a 78 L8 Fuel Injected....Have blue wire from computer to coil (works) but how does the signal go to the injectors???? The 240 wiring has many blue going back to the fuel pump...Which is the correct wire to connect to???? Does it require a plug....Any and all help will be appreciated....You may email me direct at olds442@buffnet.net

[2ManyZs]

The signal to the injectors comes from the distributor, but which wire is going to take a lot of research. If possible I will go through my service manual for my 75 and try to give you some kind of answer soon. I hope....

[2ManyZs]

I'm sorry, but before I try to do the research I have a question that has been nagging me since I re-read your post. Is there a reason that you want to put the fuel injection on the L-28 to put in a 240?? It would be my opinion that what you should do is put the intake and carbs on it the came with the 240 if you have them. With all the work to put the wiring harness in and all the associated work to hook up the ECU and the ignition control unit what you may be doing is creating a very large headache for yourself. If you have an N-42 head off a 280 the intake and carbs from a 240 will bolt right on, no problems, and with that you will save yourself a lot of aggravation and wasted time trying to put all the fuel injection harness etc. in the car. The carbs(even the later smog carbs) will do as good a job as the fuel injection, and be a lot simpler and even more adjustable than fuel injection. If I read your post right you are trying to put a fuel injected 280 motor into a 240 with the stock 240 distributor. This won't work. You would need the electronic distributor from the 280 to fire the fuel injection. There are three wires from the 280 (brown, red, and green) distributor that tie into the ignition control unit and the ECU to fire the injectors. You would need to use the wiring harness from the 280 not to mention all the sensors, and control units.

I believe it would be in your best interest to use the carbs instead of the fuel injection, it will be much simpler and a lot less time consuming.

[zoneboy2]

2manyz's: Thanks for the reply....Electronic ignition already installed.....Along with a few outher "upgrades"....I am at the tail end of the project and stuck at the wiring.....When I connect the correct "blue" wire to the correct wire leading back to the fuel pump (electric) I will have the problem solved(I hope)......You are correct about one thing, it has been a time consuming project along with the loss of hair, and discoloration to gray. Thanks again for the reply so far and any more help will be greatly appreciated.....

[2ManyZs]

Sorry that I can't help you much. Not only is this something I've never done before, I thought about it once and decided it was going to be a nightmare trying to get it right and being "electically challenged" doesn't help me much. I will say this though, I don't think the blue wire you refer to has anything to do with the fuel injectors or distributor. I believe the pump is wired to the ignition switch as it runs when the switch is on and runs constantly any time the switch is in the run position. Hope that may help some, of course not being able to see what you are doing, I can only guess at what or where you are referring to.

[2ManyZs]

I don't know if this will help you at all but in looking at the service manual for my 75 the fuel pump is wired through a relay to the Air Regulator and is then fed off the number 34 pin on the ECU. The pins are numbered from 1 to 35 on the ECU. When mounted on the car the number one pin is bottom left, 18 being top left, 19 being bottom right and the 35 pin is top right. The relay is tied into the ignition switch as I though, but exactly which relay it is on the panel is a question I don't find an answer for.