91 FC not detecting ECU anymore :(
 

so i pulled my ecu to check if anything was burnt and it all looked good i screwed it all together and plugged her in now my CEL dash light isnt even on with the ignition on and it wont start anymore? wth is going on:(

You said it looked good, but it looked like the circuit board was molded. And now you presently have 3 threads for the same problem. And you would think you would supply the pics of your ECU in this thread.

Have you checked for spark? Do you know how to deflood an S5?

i only made this one because theyre all different topics itll get more attention in this threat with this title for this problem :D and i mean it did look good nothing looked burnt at all but it was working before i unplugged it all i did was unscrew it all and look at it didnt use any force at all so then i plugged it in and nothing would happen and its not even flooded the plugs are dry after trying to start it a few times and theyres no spark now im guessing cuz the ecu shit the bed! im clueless right now:scratch:

Did you check the fuses for spark. And you say there isn't spark but did you test for spark or did you not test for spark? The Black/Yellow wire at the lead coil should have 12 volts w/key to on. Does it?

i checked for spark the old fashioned way by putting it on the fender and turning it over and looking at it and there was nothing i tried all 4 plugs :/ no luck its just ever since i took the ecu out it got messed up

Sounds like a blown fuse to me.

under dash or engine bay box?

i just checked under my dash the radio one was blown and the room one whatever that is lol it sticks out a little but i put new ones in and no luck also i checked the box under the hood they all appear to be okay...i even switched the 30s around to see if that helped but still now power or something to the ecu

Would you please check the B/Y wire at the lead coil w/key to on. Could you?

just checked it and it threw me a 0.0 for amps,ac and dc literally has no power at all

Listen to satch, and only satch. Do as he says

i will :) just wish he responded faster :lol: :blush:

she needs your help satch D:

https://cimg1.ibsrv.net/gimg/www.rx7...127410ac59.jpg

Check the 15 amp engine fuse (interior fuse box). If it was good then the B/W wire at the main relay's two wire plug would have 12 volts (and that's DC not AC or amps etc).

yeah that fuse is fine and there is no power going to the relay. the only click i hear is one of the solenoids or w.e in the engine bay! im just confused the car ran then i wanted to check the ECU for burnt stuff and i plugged it back in then now this is happening

Check the B/W wire at the relay w/key to on and while your at it look at the 4 wire plug in the same relay and check the voltage (no key necessary) on the two wires which are W/R and W/L.

is this the main relay? its next to the trailing coil pack and i got 5.3 volts out of the plug

https://cimg5.ibsrv.net/gimg/www.rx7...f918517197.jpg

also before any of this happened that Gray colored plug for the vacuum lines use to click with the key on and now it doesnt do anything

Does the main relay have two plugs (say yes). One plug has two wires ( Black and a B/W) the other plug has 4 wires (B/W, B/G, W/L and W/R). The relay is bolted to the fender near the trailing coil.

oh yes okay yeah i unbolted it and looked at it and it had like 6 wires coming out of it lol so i unplug them and test the volts from the harness end of the cable?

OKAY i just checked them both and theyre 11.7 volts DC each my battery is a little low also so had to be quick :p

So, W/L and W/R both have close to 12 volts but the B/Y wire at the lead or trailing coil has very little if any voltage w/key to on? And the relay needs to be plugged in since the White wires are run to the relay so the relay can relay the voltage to the other wires (B/W and B/Y).

they both read about 11.7 per test! i disconnected the 2 wired one first then turned the key on and tested it and it was 11.7 then i unplugged the 4 wired one and tested that and it was also around 11.7. so its getting power i guess lol what do you want me to do next?

No. There are 4 wires in one plug. You stated both White wires had voltage. You were then asked to test the voltage on the B/Y and B/W wire in the 4 wire plug. Now you just stated that you unplugged the relay and said they have 12 volts each. Wrong. They could not possibly have voltage w/the relay unplugged because they receive voltage from the White wires w/key to on. All plugs need to be checked when testing for voltage on the B/Y and B/W wire w/key to on.

i checked them all :) i did the 2 wired FIRST got almost 12 then i tested the whites got almost 12 and moved up to the other 2 and almost got almost 12 and the key was on at all times. i tested the wires from the harness as if i could of put the relay on the ground AFTER i did the 2 wired one