Anyway to do this without a PFC? My A/C was not working at the time of learning and now it works it idle hunts with the A/C on. I had it tuned right after I learned it the first time.

Also...the map isn't lost with a dead battery correct?

 

Nothing is lost when turning off the power 100%.
That would not be logical for an ecu that runs an engine, now would it?????
Stop being paranoid!

 

I would also like to relearn idle. After having my injectors cleaned, my idle after warmup is very rough and lean according to my WB. When I test this theory by increasing my primary injector lag, the idle smooths out. But then I am richer all over the map.

I have Datalogit and have no problem saving my current tune, resetting, relearning, and restoring my map. But when I reset the PFC, it does NOT re-start the learning process like it did when it was fresh. How do we do that?

 

Yesterday, while f-ing with my FD, I disconnected the ISC unit electrical connector (just behind the UIM) and let it idle that way for a good long time. I wanted to see how it would do with just the mechanical idle setting. I have it set to about 725-750 with no cooling fans, electrical loads, or A/C. Of course when a load does go on, the idle drops because my ISC was disconnnected. This seems to be no big deal except for A/C. Anyway, the discovery:

When I plugged the ISC back in after idling with it disconnected for perhaps five minutes, the PFC starting learning again! It was a very dramatic vroom, vroom, vroom like I remember it when the PFC was fresh. But it didn't stop doing this after ten minutes, so I shut the car down and let it cool off. It was probably at 130 F (WT) when I fired it up again and the PFC again started learning, but this time it settled down after a few minutes, so I went through the whole procedure, ten no loads, ten with DF, ten with A/C.

Unfortunately, this didn't cure my main problem: rough, lean idle with no loads. For some reason my PFC wants to idle at AFR 15.5 instead of 12.2 or so. It seems to change the INJ in the idle region when it is not required. As soon as I disconnect ISC, I get smooth idle.

 

Turn off the O2 idle control and adjust the AFRs to what you want.
Best way to run anyway!

 

Well I guess I thought I understood that the PFC didn't allow control in the idle region when ISC is enabled by having non-zero values for the idle speed settings. Turns out it DOES allow you to control AFR using the base map.

Here's what I did:

1. Set a higher base injection value in the corner of the cruise region
2. Select the rectangle from lowest load, lowest rpm to the injection corner
3. Interpolate and update the PFC
4. Watch the AFR (using wideband) and observe, repeat 1-4 until AFR=12.2
5. Restore the injection value on the cruise region corner and update the PFC

It did a little hunting/re-learning while I was doing this, then settled down and purred like a kitten. I also tuned my cruise region by running the car at the four corners of the cruise region and adjusting the base injection until I got 14.7, then interoplated the region to get smooth values across the range. Worked great and my low-eng drivability is now excellent.

I am now a happy camper! Starting to get the hang of self-tuning.

 

Haha yeah I was just being paranoid about that, I'm assuming there is no way to do this without a datalogit? Whats wierd is a got a new battery and the idle seems to have smoothed out with the A/C load....

 

Hey Timmy, when you coming down to tune your car?