gagliano7

I am new to tuning.I have a 1992 chevy pickup with a 2004 5.3 LT headers, CAI,no cats and a voodoo 212/218 cam with a 1999 pcm 5 speed manual.I also have a mail order tune but tuner will not answer my questions.Truck starts great cold but sometimes has trouble starting when hot.I did some searching and it looks like i should increase startup airflow initial but by how much.At temps 176 and higher setting is 0.0000.

I also have a little idle hunting problem on hot starts and if i rev motor sitting still and sometimes coming to a stop.It will hunt for 3 to 5 seconds.

Any help would be appreciated.

Thanks Joe

ctd

iTrader: (1)

Sounds more like you still have idle issue's, that is a small cam & should not require many changes to get it right. You don't want to start changing tables if the basics are wrong.

Post up the tune.

wait4me

iTrader: (10)

I don't have the software to look at the file posted, however, if I had a guess, I would say you need to add more air via idle airflow table at the temperature that you are having issues with

The START UP AIRFLOW is probably not to be needing a change, Just fix your base running airflow. In EFIlive it is table B4307. For the cam you are running, my values would be:
LABELS Desired Airflow (Lbs/Minute)
ECT °F {link: SAE.ECT} In Gear Park/Neutral
-40 2.820987 2.820987
-4 2.688710 2.688710
32 2.424156 2.424156
68 1.696632 1.795840
104 1.643669 1.564355
140 1.485040 1.392421
176 1.417520 1.371210
212 1.350000 1.350000
248 1.350000 1.350000
284 1.350000 1.350000

ctd

iTrader: (1)

By chance do you have an idle log?

Yes, the BRAF looks very low to what wait4me posted.

You can look @ your MAF airflow @ idle, that will give you an idea if the BRAF is wrong. Also log Desired Idle Airflow in your scanner

gagliano7

here is my base airflow.Definately lower than what you showed.

wait4me

iTrader: (10)

YEah that is the problem then, Look at the values when it is warm, not enough airflow. That is the right table that you need to add to. Just put in my numbers.

wait4me

iTrader: (10)

After that, it if is fine when idling, then has a little hanging rpm while your truck is moving, and or coming to a stop, Go to a table that is THROTTLE CRACKER, or something to that nature of naming, In EFIlive the EXACT table name is B4309. This table adds airflow to that base table depending on mph and engine rpm to prevent stalling while moving. HOWEVER when you make a change to the BASE airflow table, all the adders get over sensitive, so you have to just pull a percentage from them to keep things in line.

gagliano7

Thanks for all your help.

gagliano7

Here is my throttle cracker airflow vs rpm vs speed.

wait4me

iTrader: (10)

You will probably have to pull 42% from that table after the other change.

gagliano7

Thanks wait4me!!

jimmyblue

iTrader: (11)

Before you get all excited about changing airflows
and such, try getting the IAT sensor out of the engine
bay (where it can heat-soak to indicate well above
real air temps).

gagliano7

It has been 35 degrees where i am.The iat temp hasn't been going very high.The iat was 55 degrees the other day when this was going on.But i will look into moving the IAT out of the engine bay.

Thanks

wait4me

iTrader: (10)

Did you even try my tables first?

gagliano7

I didn't get a chance yet.It just snowed here so i probably won't get around to it until the weekend.

Thanks

gagliano7

At 68 degrees you have the park/neutral higher than in gear.That is the only one like that.Is that a typo or is that correct?

Thanks Joe

wait4me

iTrader: (10)

No typo, put those exact in