Got my 236/242 112LSA cam installed finally w/fully worked heads and in neutral or park, it idles fine...but in gear it chugs down to 550-650 rpms. I've upped the IAC values to lean it out and raised my desired idle to 1200 to bring it up, but it wont come up, could it be that I need to allow more air to idle higher?

Before I spend money or drill holes, wanted to get some feedback on this.

Thanks!


**Edit**
Here are my datamaster log files...have 2 of them, I got on it as much as I could both times.

Log File 1

Log File 2

 

If you are going to experiment, don't drill holes, use the throttle stop screw to open it up. What are your IAC counts?

 

What TB do you have? Some aftermarket TB's dont have that little hole in the IAC passage which makes it a little harder on the IAC. I drilled a hole in mine and all is well.

Like shoebox said find out what your IAC counts are, and prop those blades open a little. Just a little movement by those lets in alot of air.

 

who did your heads?.......cant wait to see some numbers/times with that cam!

 

IAC values:

-40 = 204
-28 = 187
-16 = 162
-4 = 154
8 = 146
20 = 124
32 = 104
44 = 88
56 = 72
68 = 55
80 = 38
92 = 22
104 = 22
116 = 47

I have the stock tb....

 

Total Performance in Santee, CA...didnt get them flowed ( ) because I was already $800 over budget on this whole thing, so I had to cut somewhere.

Also, my tranny went out on my second WOT run, so I now have no 2-3 at WOT, plus I'm running rich (I think...still trying to learn all this editing stuff...a little at a time).

 

they want to know what your IAC reads on a scanner while you idle. if they are really high like in the 100+ range then the IAC motor is working too hard to keep up with the air demand needed to run the beast. if you crack the TB blades a little and that clears up your problems then you can drill into the TB IAC bypass.. not the blades for a more permanent fix.

 

Alright, correct me if I'm wrong, but with the PCM Communicator tool that I got when I purchased LT1 edit it doesnt have an "IAC Values" sensor reading.

 

You need some scanning software. Download Datatmaster or something so you can actually read what is going on. Datamaster will allow you numerous free logs before you have to buy it.

 

Downloaded FreeScan and Datamaster...couldnt get FreeScan to work for some odd reason. Tried finding a help file on the website, but nothing.

DataMaster, I gotta learn how to get it to record, cause i could get it to monitor only or record...but there were no files when I was done.

But I was watching my IAC value, and it was wwwaayyyy above 100...was hitting 156 in idle in gear or with little throttle....it went to 103 the harder I got on it.

I'm assuming then that I'm not getting enough air, so I need to find a solution then?

 

I would definately get a bigger TB. I just installed the 224/230 in my car on stock heads and it needs a larger TB so I know you do.

 

Using LT1 edit, did you bump the idle in gear, or just the idle in neutral? I had the same problem when I did my stroker, and I just changed the idle in gear parameter and it's been fine ever since.

 

High counts mean it is letting a LOT of air in. You are running rich.

 

I have the desired idle in gear set at 1200, and it didnt change at all..still idles around 550-700.

 

So I'm running way lean from idle to about 1500, then running normal or rich at higher throttle.

Is 100 ideal?