Power FC Removed airpump - should I lower the PIM?
12-08-04, 09:55 AM
#1
Removed airpump - should I lower the PIM?
I removed the airpump a few months ago and the car runs great, but the idle seems slightly more "rough" than before... I'm thinking I may be running a little rich. I drive the car a lot (hence I idle a lot 
) and I do not want to be idling too rich (fouled plugs, gas in oil, etc...).
I've read that you can lower the PIM volts to below 100% (for 1k rpm), to lean it out, but I do not want to lower it too much and possibly cause a problem. For those of you who have done this, approximatly what did you set your PIM to for 1k rpms?
Thanks
-Matt
) and I do not want to be idling too rich (fouled plugs, gas in oil, etc...).I've read that you can lower the PIM volts to below 100% (for 1k rpm), to lean it out, but I do not want to lower it too much and possibly cause a problem. For those of you who have done this, approximatly what did you set your PIM to for 1k rpms?
Thanks
-Matt
12-08-04, 02:07 PM
#2
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I tried lowering pim at 1k on my fd, and if i go any lower then 7% it starts runing rough. Also. If i leave it like that, for some reason it needs more cranking to start next time.
12-08-04, 04:08 PM
#3
Originally Posted by BoOsTin FD
I tried lowering pim at 1k on my fd, and if i go any lower then 7% it starts runing rough. Also. If i leave it like that, for some reason it needs more cranking to start next time.
12-08-04, 09:16 PM
#6
Hi....
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hey i wanna know about that too... i wanna remove my airpump and am REALLY wondering how to cure the idle. so we ARE running rich? that's what causes the idle to be rough? how-to fix!
12-09-04, 12:01 PM
#7
Hooray For Boobies!!!
Have you sent the ECU back through the idle learn process? That might help.
Without a wide band 02 it is a shot in the dark. Everybody’s amounts will vary.
But I would start by pulling 1% to 2% of fuel out of the idle cells and see how the car acts. Give it a moment to adjust it's self and then look/smell the exhaust. If it is not eye bleeding rich then you might be in the area you want.
The PIM will pull fuel out (or add, depending on setting) of that RPM range. It is a more broad range of an adjustment.
The 20x20 grid for fuel can be fine tuned (so to say) more then the PIM voltages.
Adjusting the idle cells is pretty safe because it is under vacuum and very low in the RPM range. Just do things slowly and by 1 or 2 %.
Just as an FYI: I was running 10.8:1 for an idle mixture. That was very rich and I could see people choking behind me in traffic. Plus it would blacken my bumper. I ended up pulling 15% fuel out of the two cells that I idle (one was for no load and the other was higher in RPM due to EL load). I now am idling at 12.5:1 which is much more clean and smooth. But I started by pulling out 3% each time and seeing how that worked.
Without a wide band 02 it is a shot in the dark. Everybody’s amounts will vary.
But I would start by pulling 1% to 2% of fuel out of the idle cells and see how the car acts. Give it a moment to adjust it's self and then look/smell the exhaust. If it is not eye bleeding rich then you might be in the area you want.
The PIM will pull fuel out (or add, depending on setting) of that RPM range. It is a more broad range of an adjustment.
The 20x20 grid for fuel can be fine tuned (so to say) more then the PIM voltages.
Adjusting the idle cells is pretty safe because it is under vacuum and very low in the RPM range. Just do things slowly and by 1 or 2 %.
Just as an FYI: I was running 10.8:1 for an idle mixture. That was very rich and I could see people choking behind me in traffic. Plus it would blacken my bumper. I ended up pulling 15% fuel out of the two cells that I idle (one was for no load and the other was higher in RPM due to EL load). I now am idling at 12.5:1 which is much more clean and smooth. But I started by pulling out 3% each time and seeing how that worked.
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12-09-04, 04:06 PM
#8
Originally Posted by x605p747R1
Have you sent the ECU back through the idle learn process? That might help.
Without a wide band 02 it is a shot in the dark. Everybody’s amounts will vary.
But I would start by pulling 1% to 2% of fuel out of the idle cells and see how the car acts. Give it a moment to adjust it's self and then look/smell the exhaust. If it is not eye bleeding rich then you might be in the area you want.
The PIM will pull fuel out (or add, depending on setting) of that RPM range. It is a more broad range of an adjustment.
The 20x20 grid for fuel can be fine tuned (so to say) more then the PIM voltages.
Adjusting the idle cells is pretty safe because it is under vacuum and very low in the RPM range. Just do things slowly and by 1 or 2 %.
Just as an FYI: I was running 10.8:1 for an idle mixture. That was very rich and I could see people choking behind me in traffic. Plus it would blacken my bumper. I ended up pulling 15% fuel out of the two cells that I idle (one was for no load and the other was higher in RPM due to EL load). I now am idling at 12.5:1 which is much more clean and smooth. But I started by pulling out 3% each time and seeing how that worked.
Without a wide band 02 it is a shot in the dark. Everybody’s amounts will vary.
But I would start by pulling 1% to 2% of fuel out of the idle cells and see how the car acts. Give it a moment to adjust it's self and then look/smell the exhaust. If it is not eye bleeding rich then you might be in the area you want.
The PIM will pull fuel out (or add, depending on setting) of that RPM range. It is a more broad range of an adjustment.
The 20x20 grid for fuel can be fine tuned (so to say) more then the PIM voltages.
Adjusting the idle cells is pretty safe because it is under vacuum and very low in the RPM range. Just do things slowly and by 1 or 2 %.
Just as an FYI: I was running 10.8:1 for an idle mixture. That was very rich and I could see people choking behind me in traffic. Plus it would blacken my bumper. I ended up pulling 15% fuel out of the two cells that I idle (one was for no load and the other was higher in RPM due to EL load). I now am idling at 12.5:1 which is much more clean and smooth. But I started by pulling out 3% each time and seeing how that worked.
. I will give this a try.
12-09-04, 11:01 PM
#10
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I turned mine off. If i try and lean out cell that i'm idling at, it stars to idle really rough. and I didn't take off maybe like from 110 that was set to like 105 or 100.
12-10-04, 03:58 PM
#11
Where did the boost go??
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Interesting, I've had rough idle on the car and had to raise the idle to about 950RPM to 1000RPM (by the idle screw since I haven't figure out how to do that with the Commander yet) in order to keep the engine running. I finally hooked up a new wideband O2 for the first time last night to monitor and play with the FC settings (it was at first 121 (1.214) for the correction setting and read around 10.4AFR or 10.5AFR), when I leaned out a few cells in the correction map to about 100 (1.000), the engine idled smoothly and the stinky rich mixture smell was gone, and O2 reading went up about 11AFR or 11.1AFR. What's everyone's setting for idle?
Last edited by GTPilot; 12-10-04 at 04:09 PM.
12-10-04, 09:12 PM
#13
Where did the boost go??
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Originally Posted by cewrx7r1
My idle is about 13.8AFR.
12-10-04, 10:23 PM
#14
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My car idles at 5th row down, 4th row to the left. and I set it to 100 because if go any lower it idles rough. And yet, with midpipe it still smells rich and o2 reading is .80
12-11-04, 01:00 AM
#15
Where did the boost go??
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Originally Posted by BoOsTin FD
My car idles at 5th row down, 4th row to the left. and I set it to 100 because if go any lower it idles rough. And yet, with midpipe it still smells rich and o2 reading is .80
12-13-04, 06:59 AM
#16
Originally Posted by cewrx7r1
No where have I seen anyone mentioning if they turned of the O2 idle control which is the second step aftre removing the air pump.
.So I screwed around with this yesterday. My car idles in the (2,5) slot (2 to the right, 5 down). the number was originaly set to 121 and I lowered it 115. It seemed to clear things up. but not fully - I will let it settle for a day and lower it some more.
On my warm-up (1600 - 1900 rpms with AWS removed) the car is in slot (4,4) and it was set to 1.06. I get a lot of little "pops" durring the warmup, so I lowered this slot to 1.03 and it did't help out too much. I'll lower today and see what happens.
Since I such a newbe to this, I'm assuming such small changes are alright. Is there some point where I shouldn't go any lower (like 100 or something)?
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