Building quality engines that perform well, start on demand and stay together when the throttle plates remain open is an art. For a factory 3rd generation rx7 to be running properly, the wiring harness and the secondary electronics and vacuum systems must be in working order.

 

The right testing matters, the ground strap from the battery to the shock tower, then to the block. It looks ok, but when tested, the ohm meter doesn't lie. These windings from 30+ years ago can and do corrode and grow resistance over time. The other thing is that when testing, the temperature of the part also comes into play.

 

We found that the grounds to the ecu were just as susceptible to heat, so we added redundancy in critical areas where the on/off switching was signaled by the ground wire. Details matter. Testing every ground throughout gave us reason to eliminate another grounding failure. What looks good, isn't always effective.

 

Take the other component, the purge control solenoid valve. Works, clicks on start up, remove it, test it, it opens and closes. Nothing to worry about, right? Wrong. This controls the vapors from the fuel tank and delivers them to the intake manifold to keep the fuel system from over pressuring as fuel is consumed.

 

We took the heat gun to it, raised the temperature and at rising temps, we saw the resistance go up with it, thus after several miles the unit failed to work. This means no release of fuel vapors into the intake and more pressure building up in the fuel tank. Bad situation.

 

Testing matters, process and paying attention to the details on these classic cars is critical for solid outcomes. This vehicle doesn't have the luxury of the refined OBD2 system, so we must rely on improved diagnostics and critical thinking.

 

it doesn't matter if you are going the stand alone ecu method or using the OEM harness, this isn't just remove, rebuild and install, start it up.

 

Testing and verification of operation at various temperatures and drive intervals make or break full rebuilds.

 

Owning and driving a rotary engined performance car is not that different than the others, what matters is the way you take care of it, the people that help you make solid power without sacrificing reliability and how hard you are on the equipment.

Because we are in Colorado, high altitude and hot temperature, stock cooling works for stock motors, keep them cool with the right knowledge and bits.