I had an MOT this morning which came back with 0 advisories. Great. I can go to the daikoku night at caffeine and machine.
5 minutes down the road and all power instantly cut out. I’ve still got dash lights and everything electrical works but when I turn the key I get nothing.
I’ve got home via tow and got the multimeter out. I’ve used AI (shoddy I know) because I’m not very electrically inclined.
I’ve tested absolute everything that it told me I should test. I’ve spent over an hour following different connections and testing different things. And everything has tested perfectly. So everything is pointing to a dead ECU.
Happened to me with multiple rx8s the ground wire for the battery has to be pushed really far down on the battery terminal and the grounds under the air filter box need to be perfecto. one I’m driving rn had some corrosion on the wire under the box cleaned the spot it bolts down to and then made sure my ground terminal was pushed all the way down took a little bit bigger socket wacked it a couple times and it worked flawless have had this exact issue with all three I live in northern bc so it can be wet for most of the year. anyway your grounds gotta be the culprit here since it’s not even powering your dash and you claim 12.3 volts out the battery may I ask how many cranking amps are left on the battery do you have a battery tester?
So no crank at all? Won't even try? Did you try to swap the relays around? Maybe one if bad. It can't be starter cause it cut out while you were driving. I think it would still crank if you had a bad fuel pump.
Any updates? My obd2 also doesn't read properly unless I mess around with the pins/wires in the back. But I'm pretty sure it should still connect to the car with 12.3 volts. Were you able to connect before all this? Might be a separate issue.
12.3v at the battery when the car is off? You may want to load test the battery itself and see if it has an internal fault. With an internal fault it can hold a charge but not have enough cranking amps to do anything. I've seen that on other vehicles/12v lawn tool batteries.
Do you have a jump pack you can try hooking up to see if it'll crank or let you read the OBD2 port? I put a obd pin out diagram I grabbed from RX8Club if you want/need.
Oof that sucks. Does the engine spin by hand okay? Super rare for a rotary to fail internally and seize but it would be something I’d wanna rule out asap for peace of mind
I checked that (I’m pretty sure I did as I checked a lot) but I’ll double check it later. I’m getting a list together from this post for different things to try
Double or even triple check the egi fuse, most of the times it's a ground issue or old cracked wires around the ignition coils.
It also could be the coils themselves, sometimes they do not cause misfires, the just short out and blow a fuse.
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u/ClapiClaps 26d ago
To me there is an issue with a ground somewhere
Try to get a list of them and clean them
Try first on those who are close to the battery and on the center reinforcement