resetting fuel trims
 

to start, yes I have searched the forum...everything I see that sounds similar to whats going on with my car says to reset the fuel trims, but I have no idea how to reset the fuel trims...also, I have reset the shaft sensor and the NVRAM to help with relearning...but I still have no idea how to relearn them...someone please help me

simple way:
get in your 8, put the key in the ignition. Start watching your oil pressure gauge (top right), turn the key to the "on" position, and immediately start pumping the brakes. You don't need to put all your effort into it, you only need to push enough each time so that the brake lights trigger on, and off when you release them. It will take 20-25 pumps like this, then you will see your oil pressure gauge sweep to the right, then back to the left. Once you see that, stop pumping, turn the key back to "off". Fuel trims and e-shaft sensor are reset.

Slightly easier:
disconnect the negative terminal of the battery, leaving it off for about 30 seconds (or more, but should be at least 30 seconds). Reconnect. Everything is reset, including all your radio pre-sets, clock, ECU...everything.


Your idle will probably be a bit rough, and might not want to idle smoothly for a day or so after you do either.

yeah, I did that...but it is still back firing and not wont idle right, nor will it accelerate as fast...

You can also pull the room fuse to reset fuel trims. Read this thread...

https://www.rx8club.com/series-i-trouble-shooting-95/real-way-clear-memory-169443/

but doesnt it have to relearn them?

, just drive the car and after a few cycles it will relearn. If problem persists, its something else.

As robrecht stated, just drive your car and the it will take car of the rest.

I just tried this to hopefully reset my ESS check engine light after doing a seafoaming. I never saw the oil meter jump at all even after like 30 pumps on the break.


edit:

I tried with key at ACC on at ON (i've seen differences in threads as to where it should be.

Nothing ever happens.

looks like it worked after all....

Sounds like you are running way too rich.

If the fuel trim/e-shaft sensor isn't the issue, check these:

- Clean MAF sensor, inspect wiring
- You might need a new O2 sensor, it could have failed and stuck with a too-rich reading. When they fail they tend to hold steady on the last reading they ever had.

it is running way to rich...but I just replaced the 2nd O2 sensor, but I havent checked the MAF sensor...but I do know its missing also

Well, if you are missing the MAF sensor, I'd be surprised if you could even keep the car running, much less move it.

When I first replaced my coils, I forgot to reconnect my MAF sensor. It was running so rich that fuel was puddling under my tail pipes, trying to flood instantly, and I could not rev above 4k, period, just choked out from too much fuel.

well, I found out what was wrong with it today...0 compression on the 1st rotor, and like 3/4 compression on the 2nd one...

I'm curious how you came to this conclusion.
You're telling me you have 0 compression on all 3 rotor faces?
And then only 3/4 (or roughly 70-80psi) on all three faces of the 2nd rotor?
Please tell me what you did to get these results!

If u have 0 compression would the car actually start?

There are only 2 ways you can have 0 compression:

1 - The engine isn't turning over
2 - You don't have a rotor inside the housing.

Even with missing apex seals, you will still get a tiny bit of compression as long as the engine is turning over fast enough, and ~250rpm should certainly be fast enough.

Generally, when a compression test comes back with a reading of 0, the tech isn't doing the test correctly.



The next question I have though is:
Is it a compression of "zero" or "no compression"? they aren't exactly the same thing. If the tech tells you "no compression", he could actually be meaning "not enough compression", or "definitely below minimums", but certainly not "zero"