Mike K.

Its just that sometimes the things it tells me I can't believe and I don't know whether or not to trust it to tune the idle VE and even MAF values via the % error method.

2002_Z28_Six_Speed

iTrader: (19)

Incomplete combustion is the enemy of the wide band sensor. Any free O2 sensor at that. Especially with a big cam at idle. I have even heard that 5 gas machines are not always right.

Tuning by definition means you are guessing and checking. Hence OEM's often bag exhuast and perform extensive tests on it. Sometimes guessing with no check is the only way for those without million dollar budgets. You must decide when to believe in yourself or in the instruments.

I think I indirectly answered your question. But:

Modify your VE to what your instrument says and then throw out data you believe can not be right. Obviously, if the data changes too much from one cell to another then something is wrong.

Mike K.

right this is what I figured, damn I got my work cut out for me.

jetblast

just give her fuel and timing until she runs with a bit of putter, shell run smoother with a richer mixture. mine likes 13.5 and 19*.

Mike K.

man the more fuel I give mine the worse it gets, If I go leaner the surging goes away but then I have problems with the AC lol. My wideband acts weird what happens at idle is that right before it goes rich like from 14.6 to in the 13's the idle dips, then it surges to a couple hundred rpm past the set idle value and on the way up it moves from rich to lean and just before I hit my peak 200 to 300 rpm above idle surge the wideband shows lean like in the 16's, its almost like its behind or something. or like the car goes rich for whatever reason the idle sinks and on the way up it tries to correct by going overly lean.


How I am gonna correct this I have no idea. I've messed with so many things now I'm not sure what to do. Oddly enough when I had it in speed density it seemed to idle fine after I tuned the VE, I plug in the MAF and surge away!!!

edcmat-l1

iTrader: (10)

You can get it pretty close using the WB, or even NB for that matter. The bigger the cam, the leaner your VE will end up looking down low.
Make sure there are no abrupt increases in the cell values surrounding the idle area. Especially in the lower vacuum, lower rpms. That will add to the surging.
And to answer your question, you cant really trust an 02 sensor at idle with a big lopey camshaft.

edcmat-l1

iTrader: (10)

PS Depending on your cam, you may be better off in SD. Can you post your tune?
The going from rich to lean could be the way you have you VE set up. Is it rich in the cells that its hitting when it starts to surge?
How do you have you idle set? What are your iac counts?
Need to post a tune and a log if possible.

2002_Z28_Six_Speed

iTrader: (19)

I was thinking that too when he talked about his idle problems. There is no way the factory cal is right for his car!