Rich Idle Issue

[mikeyv]

I recently put in a new cam(219/224 .600/.600 115) in my 2000 Camaro SS and I've been re-tuning my ve table to get everything back in check. My issue is my afr at idle. It first read 12.8 so I decreased the ve in my idle map but no matter how much I decreased the ve it stays rich. Right now it's sitting around 13.5. The thing that I don't understand is if I'm coming to stop, as soon as I hit 1 mph or 0 mph its like a switch and goes right to 12.8-13.5. If i'm in the same map region at idle but above 3 mph it reads fine-14.7ish. I've been racking my brain trying to compare my old files to see if I messed something up and i'm coming up empty. It feels like as soon as it hits the idle parameters it goes rich. I've made the open loop table 1"s, I believe I disabled the maf correctly in the diag. and unplugged it, I even put 1"s in the pe table up to 1200 rpm just to see if that helped. Basically I tried to get the fueling for idle at 14.7 everywhere I could. Hopefully someone can help me out and see if I missed something. Thanks, Mike.

[printmanjackson]

do a search on how to set OL idle and CL running. Seems like no matter what you do the oxy sensors are pulling in fuel because they are seeing air from the cam overlap.

I can't remember how I set mine up but it will solve your problem

[supergt99]

thats what worked for me

[mikeyv]

I thought I set up the tune to ignore the o2 sensors completely. I don't like running closed loop because it doesn't seem to be as consistent as olsd or olmaf. I'm just trying to set up the ve first then go back to olmaf where its more consistent from day to day. My idle map is 35 and since i'm tuning in sd it is using the secondary ve table only and I think it's using the 40 map for my idle because it doesn't have the 35 map. My 40 map is richer than my 35 so I decreased the 40 map a little and now my afr is in the low 14's. It gets really lean just before I hit idle like 17-18's but I hope I can just increase the ve in those areas. I looked at one of soundengineers tune because he is running full olsd and I copied his engine diag. dtc list to make sure none of the o2's are contributing to my problem. Coming down to idle it still feels like something kicks on like an on/off switch that I can almost hear and feel. I know my car really well and I don't remember it doing this before. I'll post my tune again with the changes I've made just in case someone see's something I don't. I may just be crazy though. thanks, Mike.

[mikeyv]

Any other suggestions? I cannot for the life of me figure this one out. Its lean just before I hit 0 mph in the same cell that I idle in but as soon as I hit 0 mph it just shoots down to 13.0-13.5. Its got to be speed related or some kind of idle circuit taking over. The engine sounds like its surging a little but the rpms don't swing up and down at all. Any more advice would be greatly appreciated. thanks.

[printmanjackson]

maybe something in these threads will help

http://www.hptuners.com/forum/showthread.php?t=29875

http://www.hptuners.com/forum/showthread.php?t=10978

hope the links work

[mikeyv]

Thanks for the links but I've tried that already. I wonder if I need to rewrite the whole tune to my car again cause I recently just switched from a 2002 OS back to my 1 Bar Maf. At this point i'm getting desperate to try anything. Any other suggestions?

[printmanjackson]

you have to have the VE and MAF dialed in first. Maybe you should go back over the basics first.


maybe someone with more experiance will chime in. I've been out of the tunning loop for a while so I'm rusty

[mikeyv]

I'm trying to tune ve for now and then move on to maf. I never had this problem with my previous cam which was a lot bigger. Its got to be something in the tune that i'm just not seeing. Anyone else care to take a stab at it?

[printmanjackson]

if you can force it correct in idle with the VCM controls then you have something in your tune causing the problem.

[robbyredneck]

have you played with your raf table at all?

[mikeyv]

yes I have my raf table in check and I can command 14.7 at idle with the vcm controls. Its got to be something in the tune i'm not seeing.

[robbyredneck]

what does the scanner say your commanded afr is when this is happening?

[printmanjackson]

I had the same problem with my cam and I fixed mine going SD/CL tune using only the VE and failing the MAF then set up the idle in OL as in the links I posted. I could not get the OL idle to work with the MAF not failed. No matter what number I put in around idle in the VE or MAF the o2's would pull in more fuel. I found it was the overlap in my cam causing this.

hope this helps

[blownbluez06]

There's a rolling idle table in the 2.23 version and it's a table that exists from the factory. Once you start rolling, you get off the idle airflow table and go to the rolling idle table. Look at your commanded airflow in the scanner and you'll see it change the second you start rolling. You also move from the idle spark to regular spark tables once moving. In SD mode, if you hit the cell at idle and hit it under different circumstances rolling and get two different results, you're going to have to choose which circumstance to satisfy and move on. Once you dial the MAF back in and then re-enable it, things should straighten out.

[Throttle]

Timing in your idle table low

[mikeyv]

My commanded afr is 14.7 when this happens and I don't know why but my previous cam was larger than this one and so far was easier to tune. I tuned the last cam the same way as this one-olmaf. I just think its odd that when I'm driving and happen to hit those cells that I idle in it shows lean-16-17afr but as soon as I hit idle-less than 1 mph, its like an on/off switch right to 13.0-13.5afr. Blownbluez06 mentioned a rolling idle table in version 2.23 that could be the cause of my issue but again I didn't have this problem with my previous cam. This cam is considered a baby cam these days and should be a lot easier to tune. I'vegot the idle speed set to 875 and my idle map is 35-37. The only thing that I can think of is since i'm running sd it is using the secondary ve table and by not having a 35 map it is using the 40 map instead. My 40 map is richer than my 35. I'll try decreasing that area and see what it does but other than that I'm out of ideas. Thanks for everyones advice. I appreciate it.

[C5 2000]

1-change PO101,PO102 & PO103 to ( 2-No Mil Light ),to put you in the open loop.
2-Open Loop table is rich
3-Put the maf reading back to stock
4-Max Long Term Fuel Trims ( Min ECT to 284)
5-Also in the DTCs change PO106 to ( 3-No Error Reported)
6-VE needs work,smooth it.

[mikeyv]

c5 2000-Do I leave the p0101,p0102,p0103 codes checked or unchecked? and do you mean to return the maf hz back to stock in the engine diag.? I'm pretty sure I need to put it at zero until I want to dial in the maf. I'll change the max ltft's to 284. I thought I did that but I guess not. What does changing the code p0106 to no error reported do? just curious. I know my ve table looks a bit rough, i'll try smoothing it a little. Thanks for the help.

[C5 2000]

1-Unchecked
2-MAF Calibration table
3- the code p0106 to no error reported.( ECM ) do Diagnostic tests to measure map delta to see if the airflow Delta within-range rationality, it will reduce power and set the PO106. The engine control module ( ECM ) detects that the MAP sensor pressure is not within range of the calculated pressure that is derived from the system of models for more than 0.5 second.