Command AFR

[matthew4201]

I have been trying to tune my idle. When I command the afr to be 12, the idle smooths out very nice. What would this indicate?

Also, the o2 sensor and o2 sensor heater tests show incomplete. I have sat in my driveway for 30 minutes messing with stuff and they still show as incomplete. Do you have to drive for them to complete their test? Or would this have something to do with why when I command 12.0 afr that the idle cleans up?

Thanks,
Matt

[WS6FirebirdTA00]

It would indicate that it wants more fuel, as you added fuel and it got better...

The tests will show incomplete until a few drive cycles.

Do you have a WB? Sounds like the fueling is off a good bit.

[matthew4201]

I just went out and looked at it some more. The O2s finally came up complete. I dont have a wideband, but it looks like I need to order one.

The Stock file is the tune that came with the car. The Stock tq mgmt file is what I have on my car right now. The Lou stock file is one I found in the repository. I have used it as a reference because I assumed mine was stock, but the car has been tuned before because the tune that came with the car did not match Lou's or another stock file I found. I have increased the Primary VE table in the attempt to lower the fuel trims. They were +25 when I got the car. From the last log I did the LTFTs were down in the +single digits for most cells.

Should I be increasing the VE more on the lower rpms?

[WS6FirebirdTA00]

what do you have done to the car? Are you in SD or MAF mode?

[matthew4201]

As far as I know the motor is stock. When I set the afr to 12 it will idle good down to 600 rpm. I have been tuning it with the maf plugged in. I read over some more posts and it looks like I need to unplug it so I will be in SD right?

[WS6FirebirdTA00]

or set the fail frequency to 0. What are your fuel trims looking like? They should make up for the fuel if it was not there. You may have a mechanical issue, maybe a miss?

[matthew4201]

The last log I did most cells were +0 to +10 range. I didnt hit all the cells becuase I was using the Pro data logging because my laptop doesnt have a battery. A mechanical issue may be my problem. It does have a slight miss when idling and when you rev up the motor in park, but I had assumed it was a lean miss.

[WS6FirebirdTA00]

the fuel trims should be adding the fuel back though, +10 means it is adding 10% to get to a 14.7:1, given your sensors are still good.

[matthew4201]

Ok. Also when I rev it up to about 2k it has the slight random miss and when I set the afr to 12 it clears up just like the idle. Comparing my VE to the stock file mine are higher since I added to them. Assuming my car is stock, would me needing to add this much fuel indicate some mechanical issue?

[WS6FirebirdTA00]

it is really hard to say without having a wideband in there. Plus, if you have not failed the MAF, VE changes do nothing.

[matthew4201]

So I need to fail the MAF, get the VE tables set right with a wideband, then turn the MAF back on and calibrate it to run right? Provided there are no mechanical problems that would shoot me in the right direction.

[WS6FirebirdTA00]

yeah, pretty much

[matthew4201]

Thanks a ton for your help. I was looking at what wideband to go with and was thinking of going with the LC-1 at first but with the bad mojo Ive been reading I decided against it. Now Im looking at the powerdex AFX.

[firehawk26]

There is the new LM-2 am going to have tomorrow i will give it tray and let you know about it . and you can have it with singl wideband or dual wideband and ODB-II/CAN interface cable and SD memory card and more .

[WS6FirebirdTA00]

I like the NGK, it is cheap and good. I used it and checked it against my LM1 with identical results.

[firehawk26]

i was planing to go with it first with the NGK but as i told you that LM-2 has alot off options . l will have it tomorrow and i will let you know how it works .

[WS6FirebirdTA00]

yeah, I just did not care for the options (read extra money) as HPT does everything I need to