wiring dropping resistors/injectors

[mobythevan]

http://forums.hybridz.org/showthread.php?t=89790

 

Also, what is the best way to divide the cylinders for alternating injections or does it matter? With MS you have two banks of 3 injectors that can fire simulatneous or alternating.

[dmanzo57]

On my '78 280Z, I grouped every other cylinder in the firing order:

 

INJ1 = (1,2,3)

INJ2 = (4,5,6)

 

Using alternating really smoothed out the fuel pressure pulses compared to simulatneous.

 

I did the same on my V8 240Z, grouped every other cylinder in the firing order.

 

Don

[jkube]

I did the same, used "alternating" and grouped 123 & 456.

 

Seems to work great for me on both cars.

 

As for resistors, the 240 N/A car has the ohmite resistors as called for in MS write up. I placed them on the passenger side shock tower. Right now they are exposed to engine bay. In the spring I'll probably enclose them.

 

When I did the 280 turbo I used the resistor pack that came with the 280z. Its located near the clutch slave. Thats where I left it.

 

Both cars run well and there has not been any problems with the MS components running hot.

[Tony D]

I used a factory dropping resistor from an 81 NA (I believe) which has a big green wire to feed power to the resistor, and six red wires out to the injectors with plenty of legnth stripped out of the OEM harness to reach from almost anywhere you put the relay box under the hood. I grouped the red wires in 123 and 456 batches and attached them to Inj1 and Inj 2. The green wire went to Inj Power, of course. Worked fine for me. I used the stock ballast particularly because it had a single feed line for power, instead of two like some of the Nissan units have---and I knew the feed wire would handle the stock injectors with no problem!

[Guest Loose_Screws]

Guys, I seemed to have a problem using the stock resistors on my '77. If you look closely, the '77 has 3 resistors, 2 per cylinder. There are two of the resistors in one unit, and one resistor in the other unit. Be sure you get them divided out correctly or use 6 independent injectors. Rather than worry with this, I connected all 6 to INJ Bank 1. I seemed to have problems with idle with it connected any differently.

[Tony D]

this was not how I read the schematic, the 77 I helped hook up had a four and two resistor setup. But there was still a single power wire, and six wires out tothe injectors. We simply grouped them three and three on the ground side.

You group the resistors to the GROUND side, the power all comes from ONE source, even though the relay board provides separate leads for them.

You may have them grouped backwards! The fuel pulsations on simultaneous fire are extreme at idle, the only way we got smooth EFI pressure was to alternate the banks, 2 squirts per cycle, no pulsation that was noticable after that change.