OK heres the deal, ill have a 13b-re running on a chipped s5 tii ecu. I got soem 750cc injectors cheap but later found out theyre low imp. What do i need to do to make them work, i know i need to somehow installa resistor but how and where?

Thanks in advance.

PS if it helps I have the stock resistor block from a 86 lying around.

 

resistors yes...
10Ohm 10watt
near the ecu on the power line and not the ground of injector.

get them off of ebay.

Also "Search" with key words. resistor injector............................

 

Thanks, Anyone have a write-up or instructions of how and exactly which wires to install it on?

 

Aren't S5 T2 ecu's running low imped injectors as standard

 

No, S4s are. S5s ran high impedance and s4 ran low impedance with resistors.

If you get the FSM, you can get the pinout of the ECU. Then just cut the shielding back and wire the resistors in line with the injector output. Its so easy its painful.

 

FYI, the difference is not so much the impedance as it was the peak and hold vs. saturation. The s4 (PaH) injectors are more accurate because they respond quicker than the s5 (saturation) style. PaH injectors are given a quick jolt (peak) of electrical current to open them which once open, is reduced enough to hold them open without burning them up. Satuation style use the same current to open and keep open throughout the pulse cycle.

This current throttling is done by the ECU - your current s5 ecu will not operate them correctly and performance will diminish with respect to the correct saturation injector. Electrically speaking, the PaH injectors can work with your ecu without burning up if you use resistors.

Also, I think the s4 use an EV1 connector (square) while the s5 uses an EV6 (oval) which means you'll have to change that too. (don't some models use EV1 style connectors that have different key placement?) I'm no guru on rx7 model differences so someone please correct me if I'm wrong... ~rich

 

Damn, these are peak and hold and also have a square plug. I think im just gonna leave the install up to my local rotary shop. I hate/am scared of wiring, especially in these cars.

 

yes the connectors are different:

86-87.5 - square with center notch low impedance
87.5-88 - square with offset notch high impedance
88-91 - oval with center notch high impedance

 

They can buy and swap connectors right?

 

yeah, or just use some salvaged ones... considered trying to make a couple bucks off those injectors and just get the right ones, since they may have some performance benefits?

 

CORRECTION.

SOME S4 ran low imp, SOME S4 ran high imp.

 

Omg!! I Got Corrected!!

 

like that is a surprise.

 

Shoot, explain the difference..

 

pre 87.5 cars had a resistor pack tucked underneath the airbox and used low impedance injectors. post 87.5 did not have the resistor pack and used high impedance. But in order to run high inpedance injectors on a pre 87.5 car, you need to cut out the resistor pack and splice all the wiring to it together as one big bundle. Pretty easy. Also nice since the ECU sees high impedance anyway....