240sx engine wireing Harness

[NismoTypeX]

I need to know how hard it is to replace/install a new or used Engine wireing harness? I do all my own work usally, so I can pretty much handle it, and where do you think would be the easiest place to find a used harness for a 93' fastback/ base model?.....thanks

[NISTECH]

try a local wrecker, they arent that hard but you need to have a good memory on where every thing unplugged from. Whats wrong with your existing one that you need to replace it?

[NismoTypeX]

donno if you remember my thread about MAF functioning Problems, if not basically it a diode in my ECU keeps blowing when it gets fix and the key is turned on, the MAF sensor gets fried too, and mainly system problems because of the ECU keeps blowing, a new harness should solve my problem..right?

[NISTECH]

yea could be a short in the harness cuasing it, hard to say though, could be a component. You seem to have narrowed it down to a diode in the ECM, any idea what component that diode leads to, can you trace it on the board to what pin terminal it is at the ECM connector? Maybe then you could trace which component is on that circuit?

[NismoTypeX]

Well the technition I have working on it finally fixed the wireing problem, no longer fries the ECU, car no longer runs rich, but yet it turned very lean, and the o2 sensor is fine. Do the ohms readings on 92 injectors differ from a 93? My 93 injectors read 10.8 (they are not installed though), I havn't checked the 92' ones that are actually in the car (92 motor swap). Could I possibly have a fuel problem? Or what else could cause this Lean mixture

[NISTECH]

First are you checking the o2 signal at idle or 2000 rpm? you cant really go off its reading at idle. if it is truly running lean you may have a small vaccum leak.

[NismoTypeX]

Yea could be possible Vacuum leak, its running 30% lean. I hope its not vaccum related, sometimes its hard to trace the leak. I'm hoping to find out what my injectors are reading and looking at fuel Pressure, should be roughly 35 psi right? I'll find out all this information as soon as i get time to run test on it, My main question though is, Did Nissan change the resistance on injectors from 92' to 93'? on the 300zx's they did, im wondering if it happend on the 240sx. thanks, -Sam

[NismoTypeX]

Actually I may have multiple problems, Fuel pressure is good but , the fuel Volume is very low....so im gonna reinstall my stock pump to see if it makes a difference, and my injectors are comming up with different readings (these were messured at the harness) 2 injectors have readings of 4ohms and the other 2 injectors read 13 ohms.... so which one seems right? im not sure where on the harness these readings were taken from... (I received this info from a phone call from the tech working on it)

-Yet another wiring mystery...

[NISTECH]

13 is good, 4 is no good.

[NismoTypeX]

wouldn't lower resistance make the injectors open quicker and longer.... ?

[NISTECH]

No it would be more like a short to ground. Which could fry your ECM. With the lower resistance the coil in the injector could be shorted at a point in the windings that it is not fully energizing all the windings therefor not having anough field to lift the injector off its seat.