Can someone get my car to idle?

[BrianC98Z28]

Im sick and tired of the idle issues. It will take several times of starting it to get it to finally idle and then it will surge. Im not sure what to adjust or how much to adjust it and dont want to get anything outta wack. Will anyone look at it and see what they could do if I send it to them? Please THanks

Brian

[Redline Motorsports]

Post your tune and your mods. Lets find out what we are working with and what you have done.

Howard

[heavyfoot]

Brian, I'm fighting the same issue myself. I spent all weekend reading threads about idle tuning, RAFIG, etc. My eyes are still crossed and I'm more confused now than before. I tried to put all high level ideas together.

Give a frame of reference by answering some questions. What are your mods? Idle issues when car is cold then started or already upto temp then started? Idle issues when in gear (if an A4), Idle issues when rolling and pushing clutch in? Idle issues when coming to a stop (A4)? Not knowing any of these answers from the threads I read this weekend below is what I think I figured out. I hope someone else will chim in to let me know if I'm on the right track.

Here is my best guess as to where to go.

1. Log IAC counts. When the car is up to temp you want them around 60. They are affected by the outside temp so if it's cool outside say, 60*F they may be around 70-75. If they are higher than that you need to adjust the TB screw. Turn ignitioin off. Open the TB a little by adjusting the TB screw. Unplug TPS sensor connection. Turn ignition on for 60 sec. Turn ignition off for 5 sec. Plug TPS sensor back in. This resets the physical TPS position to 0%.

2. Log dynamic airflow (DYNAIR) and Desired Idle Airflow (IACDES_B) (note both are in g/sec). If they are not equal you will need to shift the IAC Effective Area Table {B4403} to the right. The reason here is you have moved the stock "closed" position of the TB. You have opened it so now you will be telling the PCM you have opened the TB by moving this table to the right.

3. Correctly setup Desired Airflow table {B4307} by logging RAFIG and RAFPN using 2 distict maps. Basically just set up the two maps to look exactly like the {B4307} Desired Airflow table. Setting ECT as the row and columns. Perform a copy and past labels into the row and column labels. Doing so should put ", Value" in for the column heading and the rows heading will be set up correctly as well. RAFxx will be the data parameter. After logging you will multiply with a factor back into the actual table. There is some talk about only using part of the data. I'm a little foggy on this and haven't gotten there yet.

4. Use bidirectional controls to adjust the spark timing until you reach the highest manifold vacuum you can obtain. I noted that once I got to around 28* it idled noticably better. If I continued to increase timing above 28* the manifold vacuum stayed the same or began to decrease. Adjust Base Spark in Gear {B5932} and Base Spark in Park/Neutral {B5933} to reflect the timing you achieve in above.

Personally I'm having an issue where my timing is around 20* even though my tables are set to 28*. I tried logging from a cold start tonight and accidentally missed setting up the correct precision on several of my maps along with forgetting to set up several pids. So I'm allowing the car to cool and I'll try again.

[SSpdDmon]

Here is my best guess as to where to go.

1. Log IAC counts. When the car is up to temp you want them around 60. They are affected by the outside temp so if it's cool outside say, 60*F they may be around 70-75. If they are higher than that you need to adjust the TB screw. Turn ignitioin off. Open the TB a little by adjusting the TB screw. Unplug TPS sensor connection. Turn ignition on for 60 sec. Turn ignition off for 5 sec. Plug TPS sensor back in. This resets the physical TPS position to 0%. Sounds about right. Adjust set screw to get IAC counts in line. Then perform a tps reset.

2. Log dynamic airflow (DYNAIR) and Desired Idle Airflow (IACDES_B) (note both are in g/sec). If they are not equal you will need to shift the IAC Effective Area Table {B4403} to the right. The reason here is you have moved the stock "closed" position of the TB. You have opened it so now you will be telling the PCM you have opened the TB by moving this table to the right. No. There's no need to touch this table really. The IAC is a valve that acts independently of the TB blade. The values in this table are additional grams/sec of airflow that are added per IAC step.

3. Correctly setup Desired Airflow table {B4307} by logging RAFIG and RAFPN using 2 distict maps. Basically just set up the two maps to look exactly like the {B4307} Desired Airflow table. Setting ECT as the row and columns. Perform a copy and past labels into the row and column labels. Doing so should put ", Value" in for the column heading and the rows heading will be set up correctly as well. RAFxx will be the data parameter. After logging you will multiply with a factor back into the actual table. There is some talk about only using part of the data. I'm a little foggy on this and haven't gotten there yet. Close. The values you log are added/subtracted to the Desired Airflow table...not multiplied. They are the sum of your long term and short term idle trims in grams/second.

4. Use bidirectional controls to adjust the spark timing until you reach the highest manifold vacuum you can obtain. I noted that once I got to around 28* it idled noticably better. If I continued to increase timing above 28* the manifold vacuum stayed the same or began to decrease. Adjust Base Spark in Gear {B5932} and Base Spark in Park/Neutral {B5933} to reflect the timing you achieve in above. Some people like to have the tables equal to each other. Personally, I think autos don't require the same timing to idle in P/N vs. In Gear. But, I do have some limits to my experience. Either way, 28~29* is a good number.

Personally I'm having an issue where my timing is around 20* even though my tables are set to 28*. I tried logging from a cold start tonight and accidentally missed setting up the correct precision on several of my maps along with forgetting to set up several pids. So I'm allowing the car to cool and I'll try again.If you saved the log, you can adjust the data precision in the map setup table. You don't have to log again. The .pids that were left out on the other hand is a different story. It won't log it if it's not selected.

Once you get through the above, the remainder of driveability is in the high/low octane table and IAC airflow tables (Throttle Cracker/Follower, Learned Airflow, Filtered Airflow, and Direct Airflow under Idle>Learning). As for the timing discrepency on cold starts....check B5901/B5902 (active between 33*F~121*F in my stock tune) and B5910/B5944 (active above 150*F in my stock tune). These tables subtract timing in idle areas during colder engine coolant temp starts.

[heavyfoot]

SSpdDmon, thanks for keeping me straight.

[BrianC98Z28]

it surges on startup. sometimes it will take 3-4 times to startup and idle. then sometimes after a burnout at the track it will start surging and then die, and then itll idle at 1000rpm but i have it set at 850. Its an A4 with Vig3800 stall. How do I post the tune on here??

[Doc]

Brian,
When you post, at the bottom is "manage attachments." You can post your tune there. The surging could be many things at this point. I would tend to think either fuel or spark. If you have successfully done the AutoVE procedure then look to the bidirectional controls for Spark. If you haven't gotten the AutoVe down yet let us know what is hanging you up. We all have been where you are at. Just let us know.

[BrianC98Z28]

take a look, its a thrown together tune.

[RUTAN TA]

If you want you can try this and let me know how it works for ya.

[BrianC98Z28]

I tried that tune and it still died upon initial startup and still surged when it started. Im giving up. Mods are full boltons A4 3800 stall, 232 228 573 571 113 cam. And it still wont come down below 1000rpm.

[SSpdDmon]

Here's something to get you a little better on track. For a cam'd car, there was a bit too much fuel at idle...and the colder ETC desired idle speeds were a bit low. You still will have a ways to go:


The MAF table is stock...because you still have the MAF enabled, it will run lean under load.
The idle will need to be dialed in with the RAFIG and RAFPN pids.
Spark should be close for both idle and driving conditions.
Turned Misfire Detection back on - but desensitized. You don't want this completely gone.
Also, if you disable the DTC enabler, you don't need to disable the MIL enabler too.
I didn't even look at trans settings, fan settings, etc. I figure you can handle the basic stuff like that.
Hopefully this will at least get you to the point where the car will run. Then you can do the whole disable the MAF, LTFTs, STFTs (CL temp enable), copy high spark to low, disable DFCO and "AutoVE" tune the backup VE/primary VE (and set PE once it's close). Renable the MAF and tune for it as well. Restore CL (STFTs), LTFTs, low octane spark, DFCO, etc. Of course, that's the cliffs notes version...but you should know all of this already.

Hope this works!

[SSpdDmon]

TTT for minor edit in previous post...

[BrianC98Z28]

SSpd the tune you posted isnt working. its saying its a php file??? repost it as the tun file so i can check it out. thanks

[Tordne]

Are you right clicking and choosing save link as? If so just click on the link...

[SSpdDmon]

SSpd the tune you posted isnt working. its saying its a php file??? repost it as the tun file so i can check it out. thanks
I had the same problem with yours. Right click, save target as... Then, rename it as a .tun file once it's on your hard drive.

[SSpdDmon]

Any luck???

[BrianC98Z28]

its better but theres still a few things. It hangs idled up for what I think is to long before it will idle down. What do I need to adjust for that? And Also it still doesnt come down to 850 like it should. Whats the adjustment needed for that?? And also it does still surge some.

[SSpdDmon]

Have you tried using the bi-directional controls? Have you done anything with the RAFIG/RAFPN procedure?

[BrianC98Z28]

no, tried the bidirectional controls, but nothing seemed to change