Hello I’m pretty new to rx7s but I managed to get my hands on a 1990 convertible for $350. It was running when parked an unknown amount of years ago. The engine was seized, I got it unstuck after lubing the rotor housings and using a breaker bar to turn it over.

Anyway it has no spark no fuel and the only light inside the car is the windshield washer fluid light. I replaced the coils and igniter with working ones off another rx7, cleaned all grounds according to Aaron Cake’s grounding procedure. Pulled and cleaned the ecu and I still have no change. Any help would be appreciated. When it cranks the rpm gauge does not move. 11/18/2021

edit: if it makes any difference the car does have anti theft. No idea if it’s working or how I would turn it off or even if it’s still in the car.

also the ignition switch and steering column have been changed at some point I’m guessing due to the extra steering column and pieces of an old ignition switch on the floor

 

Check all fuses, under the hood and under the driver side dash, especially the engine, meter and the egi fuse.

 

replaced all the fuses under the hood just checked all fuses at the drivers kick panel all are good no change

 

On a S4 there is a fuel pump jumper and TPS voltage check.

If there is a fuel pump jumper in the engine bay you can hear the fuel in the rail move.

It starts here.
www.foxed.ca - /rx7manual/manuals/1989FSM/

go to the section about fuel pump . . section 4 page F1-57 (58)

Do all the checks you can regarding Fuel to verify you can actually get the fuel pump to move gas.

The manual will be your friend.

But honestly, I'd check compression first.

 

Anti theft wiring sounds worth looking into to.
I’m basically seeing your ecu is not powering up.

It cranks but that is a separate circuit than running the engine.

check wiring at ecu. Probe it for power and continuity at ground. Do sensor connectors on the engine harness have ~12 volt on their positive wire?

Air flow meter sends signal once air comes in to turn on the fuel pump. This is more evidence of ecu not receiving power.

Go over the posted wiring manuals. Look into the main relay, ignition switch, ecu, and possibly crank angle sensor.

 

I second the main relay. Unbolt the main relay. With the key on run, back probe B/Y, B/W, W/R, and W/L wires, you should have 12v.

If you have power on W/R and W/L but not on B/Y and B/W, then your main relay isn't being triggered.

15A ENGINE cabin fuse B/W wire is the trigger for the main relay. Check both sides of that fuse for 12v.

If you find no power there, probe your 100A main fuse in the engine bay. If you have power there, look into the ignition switch. If you do not then you have a battery connection issue.



And as stated, the anti-theft circuit will only affect cranking.

 

Anti-theft or the starter cut relay is located near the main relay. Pull the relay and jump the B/L and B/G wires to bypass it.

 

finally got it figured out. I had a couple rusted and burned spots in my ecu not to mention every ground needed to be redone.

1990 rx7 convertible - grounds I fixed
-Ground cluster behind passenger pop up headlight
-cleaned the starter grounds
-cleaned the alternator ground
-ground wire going from firewall to top of transmission
-ground on the drivers strut tower that comes out of the main harness
-fixed both battery cables
-sanded to bare metal the mounting surface for both leading and trailing coils. On the trailing coil there was a separate ground leading into the harness
-cleaned the ground going to the upper intake manifold (S5, I believe on S4s it’s underneath the intake)
-fixed the ground going from the far right ecu plug connector
-redid the ground cluster that’s located somewhere I believe to the bottom left of the ecu
-sanded the ecu mounting plate, inside of the ecu itself, and the floor where the ecu mounting plate bolts to.
-Tore apart the ecu and replaced any rusted and burnt pieces with spare parts I stole from my cruise control module and redid just about every solder joint inside of it.
-redid all the solder joints on the idiot light cluster on top of the dashboard (even got the clock to work!)

I also swapped a couple other parts from a working s4 earlier like the coils and wires, and the CAS.

and rebuilt the fuel pump and extended the fuel lines to run it in a clean bucket of fuel since my tank is full of rust.

 

Thanks for following up.