Running rich, bad idle, fried ecu
 

I recently bought an '87 rx7. It has a s4 TII swap, with a s5 intake manifold, s4/s5 Hybrid turbo and Denso s5 550cc Injectors. Now, the car was running very rich and had obvious tps problems. I replaced the tps, but directly after doing so and testing to see if the new tps solved the idle problems, I went right in and I pulled the injectors because at the time I wondered if it was running larger than normal injectors (because of the richness). I realized then they were s5 injectors, as they were a different clip than the s4 bosch style injector clip. Well after I figured out how all the vacuum lines went back correctly, the car would start up but it idled worse than before, at around 3k, and when it revved, the bov would not open at all. Well, I stuck with my plans to send my ecu to have the rtek 1.7 installed that day, and today, I get a call from mike at digital tuning telling me my n332 ecu is fried. My plans for this car was to run the rtek 1.7 with 750cc secondaries (high imp) and the Denso 550's for the primes. Before I touched the car, it ran really really rich, idled around 1500rpm, and had obvious tps problems when you hit the throttle. Would all of that have been because there was a problem to begin with in the ecu being fried or was that a problem that I somehow caused?

Thank you, any and all help is appreciated. i am obviously a new rx7 owner.

Since your car is an '87, you may have the solenoid resistor pack... which is located near the AFM and stock air filter box. The solenoid resistor pack is for the low impedance injectors. If the injectors you have are series five, like you say they are, you won't need the resistor pack.

Probably fried the ecu because of those injectors.
Buy a cheap ecu and get Mike to redo it to a Rtek 1.7...check to see that you run proper injectors.
I think that should fix some problems you are having.

You may be able to run those injectors without the resistor pack.

No there is no resistor pack. Theyre high impedance. I already bought a cheap ecu and am sending it to mike. My question is was the ecu the problem and did it fry because of this or after?

Alright. Hey... You know your car better than I do.

if it didn't involve any resistors or HI impedance injectors then your guess is as good as mine.
Did you buy the car with a screwed Ecu?.or did you swap the engine and then it went all to shit?
Explain what the car was running like with "the obvious TPS Problem" .

I bought the car with what I thought was a tps problem. That meant that the idle was high, and when I accelerated, the throttle was very...bloppy, and then you'd feel it "catch" back to normal and it would smooth out. I tested the tps with a digital meter and it had a lot of deadspots, so i knew that that was bad. Mike at DT said the ecu looked like it someone had tried to fix it before so he was surprised that the car was running poorly.

I'd just Sit back and wait until Mike sends you back the Rtek.
Really,you'd just be guessin at why it did that.No sense in that,Right?
I've been throwing parts at the same car for 6 years,and I tell ya,if you get the car running,then you have done something right...then enjoy it!..(until you get another brain storm to modify!)

Very true. I was kicking myself at ever taking this thing apart. Shoulda just swapped the tps out, and left well enough alone for the time being...

Oh well. I love everything about the car, I enjoy the work that goes into a project car.

Well now I feel like an idiot. So I found the resistor pack. It had been relocated, I found it when I looked up a picture of one. Now my question is why did he run s5 injectors?

I figured it was in there somewhere. Who knows why he used S5 injectors. He obviously changed the clips... Right?

Yeah he did. So to undo all this, I am coming up with an action plan:
I already have two 750cc high-z injectors, so I might as well get two more, remove he resistor pack, and do this:
https://www.rx7club.com/attachment.p...1&d=1213971404

That SHOULD delete the resistor pack from the info I gleaned on this site. Or I could run 4 low-z injectors that I have as well. Either way I have to remove the clips and solder in the old style ones.

You can do Either/OR..(bypass or use LO imp)..
I personally wouldn't run HI and Lo together as it is like 8 ohms and 13 when you factor in the resistor pack.
Go one way or the other.
www.injector-rehab.com has injector clips,grommets.spacers ..everything you need to put the injectors back in.

No I would not run both. I think I'll just pick up two more high-z injectors and bypass the resistor pack.