fuel injection wiring screwed but looks factory and it runs like a champ

[Guest abnormal0]

I have a unique question about my 85' 300zx. It pertains to the fuel injector wiring going from the ecu to the injectors on a VG30E. I drove the car for 2 years very hard and I did a car swap, when I was hooking the injectors back up I noticed how many wires were going to the injectors on each side. there were two wires going to each side, one red, one green. I looked at a wiring schematic and it shows a red wire going to each injector and then six green wires with colored stripes going to there own injector. but I only have one red and one green. I drove the car for two years with it wired this way. I peel back the wiring on it and I find hidden a red and green grouped together and another red and green both seperately grouped together. They are color coded to go to two of the injectors, this is how it is on both sides. I look at how it is wired on the injectors and the one red and one green splits and goes to all 3 injectors, and it all looks like factory wiring and it all seemed really old cause the tape was really hard and difficult to get off. The non-used red and green have protective plugs on the the seem to be melted to the end. Can anyone explain this to me and what should I do about it?

[onefast87]

im not 100% sure but i think it has something to do with the Injector recall!

there have been some cars that catch on fire because of the wiring and the recall is supposed to fix this problem!

 

but then again i could be wrong!

[Guest abnormal0]

should I just go to a nissan dealer and find out about all recalls on that car? Would there be a problem if the engine, tranny, ecu, and all wiring in car was an 85', but the car is an 88'?

[Racinjitter]

im not 100% sure but i think it has something to do with the Injector recall!

there have been some cars that catch on fire because of the wiring and the recall is supposed to fix this problem!

 

but then again i could be wrong!

 

Onefast87 is right this wiring was part of the fuel injector campaign done by nissan. It is done properly and should be batch firing left bank and right bank.

 

The reason for the fires was not the wiring' date=' but it was the leaky fuel injectors. The reason for the wiring change was due to fuel mileage I believe.

 

should I just go to a nissan dealer and find out about all recalls on that car? Would there be a problem if the engine, tranny, ecu, and all wiring in car was an 85', but the car is an 88'?

 

I dont think there would be a problem as long as you tell them. There are only a few differences between the years. Most changes are hardware and software, but nothing major in the wiring.

[Guest abnormal0]

so is mine wired correctly and can I go ahead and hook up all the wires?

[Racinjitter]

so is mine wired correctly and can I go ahead and hook up all the wires?

 

If you want to re-hook up all the wires, I dont see a problem. I changed mine back to single fire(instead of batch fire). I didnt notice any "real" difference. So then I went back with the batch fire because there wasnt any benefits.

[Guest abnormal0]

Would you get better gas mileage with the batch fire or the single fire?

[Racinjitter]

I didnt notice any real differences at all. No mileage difference, no power difference. The same amount of fuel is going to be used as I look at it, but nissan says otherwise. I did 1000 miles worth of gas both ways, and it turned out to use about 2 gallons difference, this could just be because of my foot or weather.

[BLOZ UP]

The 300ZX does not do sequential injection at all. It is bank-to-bank until you pass 3000 RPM (and the car is warmed up, etc) where it switches to batch (all 6). Either pre-service campaign or post-service campaign wiring will do the same thing, it does not matter.

 

They are all wired 3 to 1 to save costs.

[Guest Kroi300zx]

Well thank you very much for all of your input. I feel a lot better about it now that I know that something isn't wrong. One more question, what is a sure fire way to figure out if my ecu is bad or not?

[Guest Kroi300zx]

Sorry, this is abnormal0, kroi 300zx was an old name and it automatically logged me in and I didn't notice. I think my ecu might be bad, and I was wondering if in any way is an ecu repairable also?

[BLOZ UP]

You can find ECU's for 30 bucks or so from people from these boards, z31.com, or z31performance.com

 

or $200 from eBay.

[Guest abnormal0]

I got one from ebay for $45 but it had a nice dent in it and the circuit board was crached but all the wiring on it seems good. But I don't know if it actually works or not. Is there anybody in this forum who would have a working ecu for an 85 non turbo 5-speed with analog gauges?

[BLOZ UP]

I have a 84 5spd turbo digital one...

[Careless]

I got one from ebay for $45 but it had a nice dent in it and the circuit board was crached but all the wiring on it seems good. But I don't know if it actually works or not. Is there anybody in this forum who would have a working ecu for an 85 non turbo 5-speed with analog gauges?

 

not sure if the z ecu is a layered PCB, but if it is, you're not gonna get anywhere with a cracked PCB.

 

on layered Printed Circuit Boards, there are traces (small flat wires) sandwiched between the layers. they basically make a board that would be 4 times the size become much more compact.

 

 

dont know if you know, but if the Z one is not like that, then forget i said anything, and you could be ok.

[Guest abnormal0]

honestly, I don't know, I'll have to take it apart and have a look at it. It's cracked, but the wires going across aren't broken but where you see that something was soddered into the board, that cracked. Does anyone know if the board is layered?

[Guest abnormal0]

I have a 84 5spd turbo digital one...

The turbo ecus, the injectors are wired different and so is a few other things and I don't want to go through the trouble of changing the wiring on the harness for an ecu and I've been told that the gauges won't work at all with that kind of ecu, but I'm not sure.