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-   -   NA -> TII Fuel Pump Resistor? (https://www.rx7club.com/general-rotary-tech-support-11/na-tii-fuel-pump-resistor-1089314/)

FC_DREAMS 09-08-15 09:59 PM

NA -> TII Fuel Pump Resistor?
 
So I'm just finishing up swapping a S4 TII j-spec engine into my S4 1987 NA. Now to my knowledge all I would need to upgrade regarding the fuel system would be my fuel pump correct? I'm unsure about this because I've been reading up on a couple TII fuel related threads, and apparently there was a "Fuels Pump Resistor" that came on TII models. Is this another part I need to get, and are there other fuel related components I need to get to make this engine work?

satch 09-08-15 10:26 PM

It would be advisable to get the fuel relay because it provides more voltage to the fuel pump when the engine has more load on it.

FC_DREAMS 09-08-15 11:16 PM

Is it just plug and play? Or where/how does it connect into the NA system?

FC_DREAMS 09-08-15 11:44 PM

Also, I was reading a NA to TII swap write up, and they mentioned:

"Lastly, if you're using low impedence injectors on a high impedence NA harness (87.5-88), you will need to buy resistors to wire in (Mouser Electronics - Electronic Components Distributor, I bought some 6 Ohm, 10W ones here) & you will need to modify the injector clips or buy low imp. clips and splice them in. High impedence injectors have a tab that is centered, while low impedence have an offset tab (mine did at least, chime in if some don't have this). I solved this problem by carving some of plastic out of the clips with an exacto knife."

I'm somewhat confused by this, can someone explain this? How can you tell if you have high or low impendence injectors?

misterstyx69 09-09-15 12:16 AM

you don't need the TII relay setup.
The N/A setup is fine as it supplies sufficient voltage all the time.
Case and point my 86 NA turned TII made 357hp with no mods to the pump wiring.

Hi IMP...about 10-13 ohms
LO imp..about 3 ohms..
(measure the injector with a Ohm meter across the little tabs)

You can get info on the difference of injector impedance in the FAQ Sticky.

FC_DREAMS 09-09-15 12:36 AM

Wow that was super helpful! So I'm using the tii harness that came with the engine and the injectors that came with it, so do I not have to worry about high/low impedance conflict? Thanks!

misterstyx69 09-09-15 07:57 AM

the ECU(N332 or N333) is built for HI impedance,hence why they can use a LO imp injector and a resistor box to fool the ECU to see HI Impedance ..OR use the HI imp injectors and NO resistor box.
Now if the harness has NO connection for the resistor box at the Stock air box location then it is safe to assume that it IS the Harness IF it came with the setup is for HI Impedance injectors.
IF the harness came with a connector that attaches to the resistor box then you are looking at LO impedance injectors.
Again,you have to verify this and you can do that by looking at the PICS in the FAQ Sticky.
It is either center notch(LO) or offset notch (HI).

FC_DREAMS 09-09-15 06:24 PM

If I did get a fuel pump resistor from a tii, how would I implement it into the na system?


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