· By Ryan Hogan
Setting Throttle Blades/IAC Counts for JTEC Applications
This goes for any JTEC controlled vehicle- does not matter what engine it is. The platforms are listed below:
96-2007 Viper
04-06 Viper SRT-10
96-2002 Dakota 2.5/3.7/4.7
96-2003 Dakota 5.2/5.9
96-04 Jeep I6 platforms (TJ, ZJ, WJ, XJ)
96-2003 Ram 3.9/5.2/5.9/8.0 V10 HD
When you add a aftermarket camshaft, and/or cylinder head(s) and/or a different throttle body, your airflow requirements at idle/off idle, change.
Additionally, the IAC (Idle Air Control sensor) needs to be open less on decel, else you get throttle "hang" on deceleration.
Both of these can or will be affected by air fuel ratio as well.
This is the case for all TBs- F&B TBs specifically often need to be opened up (even though it says in the instructions specifically not to) using the idle set screw to add this extra airflow required. This is because the IAC cannot move fast enough/doesn't have the resolution to compensate for this.
Usually, a 1/2 turn is a really good starting point, but should be adjusted specific to the vehicle. The full procedure (if you don't have a scan tool) to set the blades is this:
Start vehicle.
Let it come to full operating temp.
Shut vehicle off.
Disconnect IAC at pigtail.
IAC should be closed when key is off/engine is off. If not, replace with MOPAR IAC.
Start vehicle again.
Adjust idle set screw until idle rpm is ~200 rpm above commanded hot idle (650-700 is commanded in most cases)
Shut vehicle off. Reconnect IAC connector.
Done.
Getting these vehicles to idle/decel properly is not solely a function of tuning alone, but also a function of the TB being adjusted properly.