Hi, just looking for some in-site here.

The car is a 1991 Rx7 GTU. Everything was broken on the engine when I got it, and nothing worked right. Anyway, here's the mods:

- Engine is now rebuilt, with a rotary aviations kit.
- The actuators are removed
- The top intake deal is stuck open now
- First set of throttle butterflies removed
- All the broken rats nest stuff removed
- Basically anything connected to the vacuum system is stuck open
- Vacuum pump removed
- Coolant passage to the intake manifold is blocked
- Heater, and a/c system removed
- Aluminum radiator, and high amp electric fan
- Added grounds, cat back exhaust, new Rx7 cat, and a full intake system
- Oil injection system removed, runs pre-mix
- RTek ECU
- New clutch

The car idles absolutely perfect, and drives with no issues, and the car makes good power up to 6500. But once it hits 6500, the power falls flat on it's face. No backfires, just the power completely stops, and can barely make it to 6700rpm.

Every local Rx7 guru is stumped, and everything I've searched for related problems on here, is for Turbo II. The distributor thing, spark plug wires, idle, timing, and tps are all set perfect to the factory specs. The car drives perfect up to 6500. Also right at 6300 it feels like it's about to make a lot of power, then BAM no HP.

So is there something with my setup that would throw a red flag to cause this? Could be a vacuum leak, or maybe an exhaust leak? Maybe the secondaries aren't firing? Or maybe the ECU can't manage the amount of air coming in now, and I need an AFC-II with a wide-band? I have no idea honestly, and neither does any one I know.

 

I'm also thinking it might be the wide tps setting? I'm not sure which wire it is to check, but with the car warmed up, then shut off, I think I'm getting a 1.4V reading. The narrow one shows 1.04 but the tps screw about as far out as it can go.

 

Oh and one last thing, not sure if this is normal or not. But the stock oil pressure gauge shows around 5psi at idle, then 30 normal driving, and up to 60 at full throttle.

Any help...?

 

bump

 

Does this happen in every gear? Or more in the higher gears? What about your fuels?
Fuel filter or pump acting up?

 

It happens in every gear, same rpm. The fuel system doesn't seem to have any issues, and doesn't have any flooding issues when shutting off either. But the fuel pump and filter have not been replaced yet.

EDIT: I also remembered the Rtek ECU is from an automatic car, and this is a manual car. I don't think that would make a difference tho.

 

faulty secondary injector or wiring. been there done that.

easy diagnosis is swapping primary and secondary injector wires in the ECU connector, the car should idle on the secondary injectors, if it's running on one rotor then disconnect each secondary until the engine shuts down, the opposite secondary injector/wiring is faulty.

the one vehicle i had with the issue had a bad driver wire from the ECU that ohm/volt tested fine but bled off voltage when put under a load, was a bit of a pain to diagnose. ran a new wire parallel to the engine harness to the injector, problem solved.

 

Dang, thank you so much for that info. A friend of mine said it seemed like the secondaries weren't working, but he only has experience on Turbo II's.

I'll try and diagnose the wiring this week and let you know if that fixes it. Thank you again for your in-site.