mxrider914

iTrader: (3)

I have a 87 na with a s5 t2 swap. I'm running the na harness, s4 t2 ECU, s4 t2 TB and TPS, s5 t2 injectors, emissions removed, 3' straight pipe to a muffler.

My car has a horrible hesitation/ stutter when I first get on the gas, right after I shift, if I let off then get back on it. It's not to bad when I'm WOT or on it pretty good. Normal driving though it is really bad.

My question is, do s5 t2's come with resistor packs for the injectors? From what I understood they didn't and bypassed it by running all the wires together off the harness. I'm now wondering if this is incorrect. They are high impedence injectors but should I still have the the resistor pack for some reason?

Also, are all the ECU's high impedence and then just run to the resistor pack, or might I have the wrong ECU and it's sending a low impedence to my high impedence injectors?

Any help would be greatly appreciated. I've been driving it for about 6 months like this, it doesn't seem to hurt anything but it drives me insane. I've tried so many different things and nothing helps.

misterstyx69

iTrader: (142)

S5 TII's have HI impedance injectors,no resistor pack.
the 86-87.5 had resistor packs to make the ECU's see HI impedance. With LO impedance injectors and the resistor pack it sees HI.
The N332 and N333 See HI impedance.
the change came when they shoved HI impedance injectors in the 87.5 and 88 version that came wired with NO resistor pack.
your easiest remedy is to change to LO impedance injectors Or Go the "hard way" and bypass the resistor pack,IF you have it.
You really shouldn't let the ECU See HI injectors Plus a Resistor.
Edit" just saw you bypassed it.

Spirit-RE

iTrader: (25)

If you're running hi-imp injectors, you do not use the resistor box. IIRC the(early) n/a's used a resistor box, so if your harness has the big plug for the resistor box, you need to cut that plug out, and solder all those wires together.

mxrider914

iTrader: (3)

That''s what I did. I just wanted to double check it was right. I've been trying everything to get this thing to run right. I'm to the point that I think I'm going to just buy a s5 t2 harness and ecu rather then using the s4 stuff. I don't know what else to do.

Black Knight RX7 FC3S

iTrader: (7)

you have all the s4 TII parts like afm and map sensor?

mxrider914

iTrader: (3)

Yes all s4 t2. Except for the injectors.

misterstyx69

iTrader: (142)

Did you ever cut the PS wire (3D?.3 F?) at the ECU connector?.On a Tii that is knock sensor..on an N/A harness that is PS..you have to cut that wire so it doesn't bog.
Hailers had a thread or info on it.

mxrider914

iTrader: (3)

I did not! And that sounds like it could definitely be the problem. If the ecu thinks the knock sensor isn't there, since it's not plugged in, it's going to retard the timing right? And I was just about to time it. What do I do when I cut it? I would guess I need to jump it or something. If I just cut it, it wouldn't be any different then just not being plugged in would it?