Running Rich, Wont Idle-P0101 ( New Cam )

[TXZ0603]

Just installed a MS4 cam and 25% ud pulley. Started car, wont hold idle, running rich. Sets a P0101 code steadily. Where should I start on getting an idle.

Other mods include 160 thermostat, kooks LT's, 3" ORX, pace cars, tr55 plugs, exoskel clutch.

The tune was stock before, i had only modified the fan speeds for the 160 therm.

Will log tomorrow if I can at least get it to idle.

2003 Z06

[Vman]

Under the "Tuning & How To's" (3rd Sticky down from top of page)there is an excellent write-up by Bill@HPTuners, WS6FIREBIRDTA00, Frost, Russ K, Soundengineer, and all the other super techs. These are excellent source of information which will walk you through the process. I'm not the sharpest knife in the drawer and it worked awesome for my application...although not as aggressive as your MS4. I hope this points you in the right direction

[TXZ0603]

i have the cpig writeup printed out, but i need to immediately address the idle issue before I can even drive the car. It dies right after startup.

[mowton]

I am relatively new at this as well but try setting the idle RPM's (in all cases) higher say to 1000, just to get it to stay idling. Also with the 160 degree thermo, set the Adaptive Idle RPM tabe min ect to 140. It's found in Engine>Idle>Idle RPM on the left. The run Russ Kemps idle scan and set the RAF. Thats in Engine, Idle, Idle Airflow. First etry upper left. Just copy and paste desired airflow from the idle scan. I am assuming everthing else in the tune (timing, OL/CL etc) are stock.

How do you know it is running rich, do you have a WB? At startup, it will be in open loop and has a set fueling program which you need to get right. The RAF is the start.

Isn't this fun

Ed

[Vman]

A cam is less efficient at idle and requires less fuel on the bottom end; however requires more fuel on the top end. Below is something I found helpful which I can not take credit for.
If it were me giving advice to a first time person, I would tell them the following:

Cams with negative overlap up to zero, idle 850-900, add 1 g/sec to idle airflow, add 2º of idle timing 1200 rpm and under

Cams with over 0º overlap up to 15º, idle 900-950, add 2 g/sec to idle airflow, add 4º of idle timing 1200 rpm and under

Cams over 15º overlap, idle 950-1000, add 3 g/sec to idle airflow, add 6º of idle timing 1200 rpm and under

Of course this is just to get the car starting, and is not "the right way to do it" just what I have told people in the past that has helped. The fueling reduction is also based on the cam size. I will have to look through some tunes to find out a good run of thumb for that.

Other than that, the first thing to do is to get your idle fueling close to 14.5-14.7, then using the VCM controls, adjust the timing until you see good MAP (more vacuum). There will come a point at which it doesnt get much better, and that is a pretty good way to get into a sweet spot. If you get some idle surge, chances are you may have too much timing in there. Each setup will want different things (depending on the combustion chamber design). When making these changes, you need to give it some time and let the STIT and LTIT level out somewhat so you can see if it is really helping. I am sure there is more to add, and things some people may not agree with. MOST of the time, if you add idle airflow to the whole table, you dont even need to mess with start up airflow settings, but that doesnt mean you may not have to. If the car has a hard time starting, you can add 0.5-1.0 g/sec to the start up airflow settings to aid in start up.

[Vman]

More info which I can not take credit for:

IDLE TUNING

Some good things to scan:

LTIT (p/n, in gear depending on transmission and which settings you are looking to change)
STIT
RPM
Spark
ECT
MAP

just to name a few...

Idle desired RPM: Depending on the cam and transmission type will effect your RPM settings. The reason for increasing RPM is to smooth out the idle and help drivability. Raising the idle results in more manifold vacuum. After doing a cam you lose a decent amount of vacuum. For cams in the 210-230 duration range 50-100 rpm over stock works well, 230-240 range 75-150 rpm over stock will work well. Too high of RPM settings may max out your IAC motor on cold start, to stay out of that range, keep the cold start idle so the IAC motor will not be close to 310 steps.

Idle airflow: Log the STIT and LTIT and add the 2 together. With a manual you will use LTIT in gear all the time, autos will use the respective LTIT depedning on the gear selector position. Add the 2 values together (or make a custom histogram) and make chagnes based on ECT. Say 30*C STIT is -0.30 g/sec and LTIT is 0.10 g/sec, you want to subract 0.20 g/sec from the 30*C cell in the idle airflow table. It is important to make these changes only from a cold start as they will give the most accurate data. Make sure it is logging and you make corrections in metric as it adds better resolution. For starters, adding 2 g/sec to the table before initial start up after a cam can help idle.

VE table for cam: Since a cam is less efficent at idle (for the majority of the aftermarket cam world) the VE table will need to be scaled down in the inital tune to keep some fueling out. Small cams may only need 10% taken out while larger cams can have upwards of 40% taken out of the VE table. This is largely dependent on your cam.

Timing: This depends largely on the cam type. Cams in the 220 duration range can run well on 22-26* of timing, 230 range tend to run well 26-30* range and above that is trial and error as some cams may like 32* while others like 24*. See which helps your car idle the smoothest. I would recommend ADDING to the stock table and not altering the stock curve.

Take the car for a drive and check your idle. If the car goes on cruise control and the idle air is in a reasonable range (0.10-0.20 g/sec) you may need to slightly reduce the throttle cracker table. That table adds airflow while you are cruising and too much will keep the rpms from reducing.

[TXZ0603]

Thanks, Will be working on it tonight.

[LinearX]

P0101 is a MAF fail code. I don't think that anything idle related would cause that code to be set.

I'd check the MAF wiring and make sure that it's all good, and that you have a good connection to the MAF.

As for the idle tuning, follow the info posted above.