The one super crusty plug is indication that coil was firing poorly.

The stalling could just be because you revved it out before it had a chance to learn to idle. Unplug the battery again, start it and let it idle normally until it warms up.

But replace the coils first, nothing will work properly without that. That is, if you intend to keep the car.

 

Thats interesting. I have the coils coming tomorrow but all of the repairs so far have been done without disconnecting the battery. If I have time tomorrow I'll do that.....if not over the weekend for sure.

Thanks

 

Ah, I assumed you had disconnected the battery while working on it. In that case, definitely give it another try with the new coils.

 

Yea.....I'll do that and keep updating this thread!

 

Yep. Disconnect the battery and leave it overnight (and while you are changing the coils) to reset the PCM. If it starts, let it idle until it reaches operating temp. It needs to re-learn how to start, warm up, and idle without interference. After the PCM reset, it will use the equivalent of a base map until it sets new fuel trims and timing advance values.

 

Thought someone said not to let it idle to operating temp

 

Idle UNTIL operating. Further idling doesn't produce new learning, you need to go for a normal drive to round it out.

 

 

How often do you have to relearn idle? Not very.

For relearning idle, you could let it idle to warm to make sure the car runs. Just don't idle to warm on a regular basis.

 

Test your coils before you install them. Maybe after too if you have the tool for it. The new coil I bought made the car run worse than the worn out one. Bench tested it and it failed from the start. Had to exchange and took my multimeter with me.

 

We are talking about resetting the PCM and letting the car learn how to idle again as it builds its own fuel and timing maps. This is something you do once or twice after major maintenance.

Under normal conditions, you do not let the car idle to operating temp before driving it.

 

The ECU has two different types of parameters to learn.

The first is the eccentric shaft profile (analogous to the crank angle sensor). In S1 cars, this is reset using the 20-brake-stomp routine and the ECU re-learns this within a few revolutions of the eccentric shaft.

The second are the fuel trims. Fuel trims are lost whenever you disconnect the battery for more than a few minutes.
The ECU has 3 different fuel trims to re-learn. The fuel trims used are based on MAF rate.

1. 0-8 g/s
2. 8-20(?) g/s
3. 20+ g/s

Letting it idle to re-learn fuel trims only lets it re-learn the first trim. This may help if your car doesn't want to idle after the battery is disconnected. But then you have to get it up to operating temperature for it to learn because...

The ECU doesn't learn until the engine is running in closed loop (i.e. is warmed up).

During the time that it's running in open loop (cold, front O2 failure, probably a few other reasons), it's guessing on how much fuel to add based on the MAF and coolant temperature. Once it learns a fuel trim, it can use that data to help with open loop operation which is why it stops dying at idle after to let it re-learn the idle fuel trim.

 

Are we sure it stays open loop until it reaches operating temp? That is a pretty old-school approach. For example, my 2003 Miata goes closed loop within about 5 seconds of starting: after completion of after start enrichment, but still during warm-up enrichment. From there, it works off the VE table plus WUE plus baro correction plus EGO correction, to idle slightly richer than stoich as it warms up (slowly becoming leaner until stoich). Surely the RX-8 ECU is more sophisticated than to stay open loop until CLT hits 180F. Shirley?

 

I may be pulling some of that info from memory/conventional wisdom.

 

I'd imagine it will have to wait until the secondary air pump to shut off before going into close loop.

Otherwise it will read pretty lean, no?

 

o my understanding is this.....and correct me if Im wrong......(this is based on my scenario only).....


Disconnect the battery overnight.
Re-connect battery and proceed to do the ESS reset ....OR.....Deflood engine first?
If engine starts......let idle till warm up?

As I stated previously....I got it so start and run after doing the deflood procedure....was able to get it to about 5-6k rpm......and then slowly died. Now have new coils and wires in hand and will be installing those before the next round of troubleshooting.

Thanks guys....this is very informative....especially coming from a piston platform.

 

So, it died after reaching 5-6k rpm even though you were still giving it gas? If so, you've got issues to resolve that have nothing to do with the engine re-learning fuel trims. Could be a bad coil, bad or dirty ESS, bad O2 sensor, bad MAF...

You might as well do the ESS reset because it only takes a few seconds and it won't hurt anything. The car will re-learn the ESS profile in a 1/250th of a minute (cranking speed > 250 RPM, only needs a couple of rotations of the tone wheel).

If it starts, you don't need to de-flood it.
For diagnostic purposes, let it warm up at idle and see what happens. If it doesn't die after the coolant temp needle has stopped moving, give it some gas. Slowly rev the engine several times. The first time, slowly take it up to 4k RPM. Let it come back down to idle. Next time go up to 5k and let it come back down again. Repeat this until the engine dies or you get to 9k. If you get to 9k and nothing bad happens, take it for a drive around the block. If it does die, continue troubleshooting.

If you haven't check the catalyst bed, do that before starting the car. Lift the front, put it on ramps or stands, remove the 3 bolts holding the cat to the exhaust manifold. Pull down on it so that you can look at it. You want it to look something like this. You do not want it to look like this or this.

You may want to log data. Get an ELM327 OBD-II adapter and a phone app so you can log things like STFT, LTFT, MAF rate, commanded AFR, actual AFR, RPM, coolant temp, and such.

 

NotAPreppie thank you for the detailed info and your help on this situation. I will get to some more trouble shooting this weekend and update the thread. As far as the ELM327.......is everyone getting the new mini version or the older style and which app do you recommend? Thanks again

 

 

Android based.

 

Torque

 

Thanks Sydo. Any input on the ELM327 anyone?

 

pull room fuse or batt. then reset ess.

start car with ac off fan motor off.

let car run till fans kick on.

if car will not let you do this, take it for a drive till it settles down a bit and wants to run.

then start at the beginning again when it is cold. you will be shocked at how much better the car idles if you get it right.

beers

 

I have a cheap one from Amazon, and other than being large, it works as well as my expensive one. I think I paid around $10 for the cheap one several years ago and around $100 for the expensive one.

 

The weather has not been good enough to get much done with all the rain snow and now ice. But i have stock piled the new coils, wires and Bluetooth OBD2 reader. As soon as the weather permits I'll update you guys with any progress made.

Thanks again for all the help and tips guys.