looked at my EM harness that came off a 1986 vehicle, i cant seem to find the plug for the solenoid resistor package???

 

It is on the EM (emissions/engine) harness, the resistor pack itself mounts on the passenger side strut tower.

 

like banzai says its on the EM harness.

its a BIG white roundish plug

 

I tried looking and i cant find the plug,this is ****** weird,im certain my EM is from a 1986 S4. i looked at the harness dosent look like its been cut..

 

If it's really not there, then someone swapped an '87.5+ harness into your '86 donor car.

 

nope it not there
i figured
but damn! now i need to find a solenoid registor..... do i still need the solenoid registor if i have high impedance injectors???
btw thank you roataryrocket for clearing up that one

 

You need it to run low impedence injectors

 

Correct me if I'm wrong, but I thought the resistor pack was there for the low impedance injectors, so that the ECU, expecting high impedance, would see high impedance. If you have the resistor pack I believe it's underneath the air filter box along with some other electrical things.

 

Right. Either low imp. injectors (2-3 ohm) + resistor pack (6 ohm resistors) or high impedance injectors (12-13 ohm). The aftermarket option for running low imp. injectors on a high imp. harness is to wire in resistors of your own.

 

but i forgot to mention i have a S4 t2 motor

correct me if im wrong the solenoid "registor" came only in the 1987.5 cars???

 

The motor doesn't care about the electrical attributes of the injectors, it cares how much fuel it gets. To get the proper amount of fuel to the motor, the ECU cares about what impedance a flow rate your injectors have.

Also, I don't remember if it was the older or newer 7's that got high or low impedance. I replaced mine like two years ago, I know my secondaries are 720cc, I have the resistor pack and so also low imp injectors, but my TII is a 1987 and I don't remember if it's a 1987.5+ or not.

 

so what do i have to do to get it running correctly
sorry this whole thing got me confuse,please direct me to the right direction
thanks

 

What # ECU do you have and which color injectors?

 

i have a n332 ecu and the i have the square type injectors 195500-1350 but cant tell if its red or purple, but i believe the motor is a 1987 T2

 

I'm assuming this is a swap of some kind? '86 had no turbo models, so I'm guessing this is an NA emissions harness for a TII swap?

I also wouldn't go by injector color. I have a number of injectors that don't conform to the colors listed in the FAQ. The FAQ says purple TII injectors should be high imp., but I have some that are low imp. The offset of the tab on them, or measured resistance are the better ways to check. Low imp. injectors have a centered tab where the clip plugs on, while high imp. are offset.

It boils down to this: If you have high imp. injectors (offset tab) & a high imp. harness, you're set. If you have low imp. injectors (centered tab) & a high imp. harness, you need to wire in your own resistors.

And for clarity, '86-'87.5 cars used low imp. & '87.5-'91 cars used high imp.

 

Straight from the FAQ about FC's:
What size injectors does my RX-7 use? What colour are they?
Year Engine Plug Size Colour Part #
84-85 13B NA, low square center, 680cc, orange, 195500-0900
86-87 13B NA, low square center, 460cc, red, 195500-1350
86-87 13B Turbo, low square center, 550cc, tan, 195500-1370
88 13B NA, high square offset, 460cc, purple, 195500-1350
88 13B Turbo, high square offset, 550cc, purple, 195500-1370
89-91 13B NA, high oval center, 460cc, red, 195500-2010
89-91 13B Turbo, high oval center, 550cc, purple, 195500-2020

 

According to your part number, you have 460cc N/A injectors, this is a problem and one of the reasons your car is not running well.

 

okay i narrowed it to this i have a 87.5 NA EM harness with a 87.5 t2 motor
i have a 87 t2 motor because my injectors have a off center notch/tab meaning its high impedance injectors, right?

 

You say this like you aren't sure it's an S4 13Bt. Having 'x' injectors doesn't necessarily mean they were originally matched properly with the motor, ECU, or anything. They could have thrown whatever fit in there and called it good... You must match the injectors to the ECU, forget about what the motor is until you get the first thing figured out. If you do know it's an S4 13Bt, then good, it should work once your injectors are replaced with the ones that match your ECU.

 

im sure its a s4 t2 its just that its a 1987.5, around that year things change like the injectors


oh **** my bad i probably give u the wrong serial number ill go double check wen i get home

 

The point is that the early 1987 TII injectors were 550cc, and the 1987.5 and up TII injectors were also 550cc. It won't matter if your TII motor is Jan 1987 or December 1987 built, or even 1991 built, it will still use all 550cc injectors. What matters is that they're matched to the presence or lack of the resistor pack and the proper ECU. The ECU part you have covered already, so you're good there.