ROUGH tuning logs: Car wont' drive, so I'm working to get it drivable

[Kevin Doe]

I did several logs.

Log_0018 - This los shows very lean conditions right after small throttle movements.

Log_0019 - This log shows a very lean startup around 20:1, and slowly ramping down to ~14.5:1 AFR.

Log_0020 - This log shows very lean conditions right after small throttle movements. This was an autoVE log, and at idle, it looked like I was in the 70 kPa cell at 800 rpm. I had a lot of data there, and the BEN was 1.06.

I applied the BEN, but since it was only one cell, I did it by hand. I multiplied the 400 and 800 rpm rows by 1.07. I multiplied the 1200 rpm row 1.04.

Log_0021. This log is an autoVE log as well. I wanted to see how my VE corrections did. From the new BEN, it looks like my corrections had absolutely no effect on the newly calculated BEN. Is the VE talbe even used at idle? Why would my corrections make no differnce in logs done within 10 minutes of each other?

Here is my current tune. Not much done to it. The car is not drivable, so I can't do any autoVE tuning. Right now I am really just grasping for any help I can get. I've tried many different things. Finally it looks like my warm idle is at ~50-60 steps.

I'll attach the logs and my tunes in a minute, when I figure out how.

[BlackGMC]

Did you follow the tutorial? I think you need to disable the STFT, B4206. I think your corrections had no effect cause your STFT are still active. I may be far off but it is worth a try.

[Kevin Doe]

I followed the autoVE tutorial for setup, unless I missed someting, I'll go back and check though.

[BlackGMC]

Disableing the STFT is not in the tutorial. I found it out the hard way by searching threw threads.....

[BlackGMC]

chech out this thread, I had a similar problem.
http://forum.efilive.com/showthread.php?t=4799&highlight=autove

[Kevin Doe]

Ok, I looked through the tutorial again. Step 10 is confusing. It reads, "Open calibration {B3801} "Long Term Fuel Trim Correction" Set it to Disable calibration {B4205}

What does that even mean? Do I disable both B3801 and B4205?

[BlackGMC]

B3801 refers to the disableing the LTFTs. B4205 (I think you typed it wrong) refers to the table. The tutorial should include B4206 set to disable, from what I have read. If your still really lean you might need to increase the VE more to at least get it going.

[gto_in_nc]

Looks to me like your VE table is significantly low. Looking at your BENs in Log_0021 (and assuming the numbers from your LC-1 are meaningful (does LogWorks2 give you similar readings?), I would start by increasing the whole VE table by at least 30%. I would also bump up the desired idle speed to like 1000 RPM to help keep it running while you do some initial tuning.) Then I would do another brief AutoVE like Log_0021, mostly idling but also gentle blipping the throttle just a bit. Then look at your BENs. You should see numbers much closer to 1.00 than the 1.3 to 1.7 you are getting now. If NOT, stop and ask for help. If the BENs have gotten closer, I would apply them to the VE table and then do another brief AutoVE log. If the results of that now are much closer to 1.00, I think you can breathe a little easier and start to slowly & cautiously start doing AutoVE. You'll want to take baby-steps until you are in the right ballpark.

EDIT: BTW, there are LOTS of people on here who are much more knowledgable and experienced than I am. I am hoping that anyone taking exception with anything I suggest (in this thread or elsewhere) will chime in ASAP to correct me (and to prevent me from steering someone in a dangerous/foolish direction!)

[Chevy366]

B3801 refers to the disableing the LTFTs. B4205 (I think you typed it wrong) refers to the table. The tutorial should include B4206 set to disable, from what I have read. If your still really lean you might need to increase the VE more to at least get it going.
Just so it does not drive people crazy looking for [B4206] , not all .tun files have that cell , COS3 05s don't have it .

[rosey]

It seems that the values in your VE table are very high in the low rpm range...the VE of the engine should be quite a bit lower than stock at low rpm with a large cam like you have. I would guess either the car isn't properly in open loop/speed density mode for some reason, or there is a mechanical problem. Are you sure the car has good fuel pressure? Are you sure all the cylinders are getting fuel and firing?

You also might want to take a look at b5932(base spark). Your spark timing swing looks to be huge at idle, and adding some timing in may help. You'll want to try to get the engine to pull as much vacuum at idle as possible, it helps to use the bidi controls in the scan tool to see what the engine likes.

[SSbaby]

I notice a few things...

I notice the tune is permanently in Open Loop as Closed Loop Temp Enable = 122*C (i.e. it will never enter Closed Loop).

Your VE table isn't very smooth for a cammed car. Cammed cars are very sensitive to variances (swings) in VE values. As a comparison, here's a screenshot of my VE table (cam is 224/224 110 .568")... (Note: I'm not a huge advocate of AutoVE). My engine behaves much like a stocky - idles nice and pulls smoothly, even from 800 rpm in 2nd.

http://img.photobucket.com/albums/v712/SSbaby/VE_smooth_ssb.jpg

I agree with the previous post that your idle VEs appear to be too rich. This would cause an erratic idle and stalling issues.

Maybe also reduce your swings in table {B3605} "Commanded Fuel When in Open Loop (Normal) for starters (i.e set EQ Ratio closer to 1.0 for temps greater than 10*C).

I also note your spark tables (hi-lo and base) are quite low for a cammed car.

Just my 2c.

[Kevin Doe]

Please refer to this thread. I think I may have identified the issue. Well not me, but someone else has pointed it out to me. Read the thread and tell me what you think as well.

http://forum.efilive.com/showthread.php?t=6417

[joecar]

That's it: when the PCM sees a MAF DTC it goes into SD.