Hey! I've got a 1988 FC Rx7 SE (base model) AUTOMATIC. I got this car about 8 months ago now, but it was having some glaring issues that I needed to finally give attention. The automatic transmission was on its way out, (just lost reverse), and it wouldn't hot start due to extremely leaky injectors (smell of gas after shutting it off, puddles under intake). So, I decided to bite the bullet and get to fixing.

WHAT GOT FIXED/WORKED ON:
- Air cleaner, throttle body, intake manifold all removed to access injectors
- Emissions vacuum rats nest delete from Atkins
- Primary injector replacement from FIVE0
- New primary injector wiring harness connectors cut and replaced (soldered & heat shrink)
- Secondary injectors cleaned, rubber seals replaced
- Fuel pressure dampener delete from Atkins
- Most fuel lines replaced in engine bay
- Starter, drive shaft, & exhaust removed to access Automatic transmission
- Automatic transmission removed, used one reinstalled
- Torque converter removed, drained, cleaned, refilled and reinstalled to new trans
- Installed coilovers while she was in the air anyway

After putting everything back together, it wouldn't start. More specifically, key 2 clicks would light everything up like normal, and it cranks over plenty, but it doesn't even try to start. No sputter or anything.

DIGGING INTO IT:
- First, tested for spark at the coil (coil wire to spark plug), nothing. No power on multimeter
- Took plug out, hooked up coil wire to it, tried grounded the plug to test for spark that way, still nothing.
- Unplugged white 2 pin connector plugging into the coil pack on drivers side, no power coming from harness with KEY ON or while cranking.
- Next, I jumpered the yellow test port on passenger side to test fuel pump, that works fine.
- Cranked over for 15 seconds with spark plugs reinserted, removed them to see if they are wet (injectors firing), they were bone dry.
- ENGINE fuse inside cabin (driver kick panel) still good.
- Main injector 30amp fuse in engine bay still good.
- MAF tested and still good.
- MAIN RELAY clicks on with the key, and seems to be working as intended.

OTHER NOTABLE DETAILS:
- Previous owner wired a wire directly from harness (harness right next to main relay) to the starter tab (presuming this is why its cranking)
- The Tach DOES NOT jump when cranking, so possible CAS issue?
- There is a random yellow wire with a black connector hanging off of the shift linkage harness on the transmission side, right next to the starter. But it wasn't plugged into anything before and the car started and ran fine. I think this used to go on the starter instead of the bypass wire.
- Buzzer kicks on after 10 seconds with KEY ON and doesn't stop until key is back off (I think this is just an unresolved coolant level sensor ground issue)

POSSIBLE LEADS (so far):
- Neutral Safety Switch / Inhibitor Switch
- I spent a long time looking into this, and I *think* this only controls the starter, which is already bypassed, via that yellow wire. The 4-pin connector the the FSM points to is plugged in fully, and I took it out and cleaned it and reinstalled for good measure.
- Nothing changes when attempting to start in Park, Neutral, or any other gear.
- ECU Ground
- This ground was a little crummy, so I removed it, cleaned it up, and cleaned a new surface for it to mount to but that didn't fix much.
- Fuel blockage
- Bottle test shows plenty of fuel is reaching injectors
- Random black wire dangling from engine harness
- Friend told me this was just the oil level sensor and they break

So here's where I'm at. My current theory is the ECU is cutting fuel and spark because it isn't happy with some signal it isn't receiving. I've been pouring over this for about a week now with the help of other FC nerds but we are all stumped. Obviously it's probably something we F'ed up, or forgot to plug in, but any help would be appreciated. I automatic to automatic swapped this car because 1 I wanted the experience, and 2 I didn't have the funds for a nice manual swap at the time.

 

I'm not too terribly familiar with the automatics, but this same thing happens in the manual cars too.

From what I can recall, the ECU will not tell the fuel pump to run or the coils to fire, UNLESS it sees crank signal from the CAS. I would test/inspect that, and go from there

 

if you have an extra CAS, you can plug it into the harness and with the Key On and engine off, you can spin it by hand and you should hear lots of clicking as the injectors and plugs fire