So my engine is getting close to running and I've discovered that I need to set idle somehow. The engine is a toyota 2rz that uses a PWM IAC which (I believe) is also actuated by a bi-metallic spring that has coolant flowing over it for cold-start high-idle. I am running a turbo and a DIYPNP with MS2/extra. There is no idle adjustment screw. The IAC has an inlet hose that connects pre-throttle body.
I've gotten my engine to start up and run with the IAC inlet hose plugged and 1-2% throttle via the pedal. Otherwise, the engine will quickly die after cranking (with the IAC inlet blocked) or rev up to ~1600rpm and then die with the IAC inlet open. I do not have the electronics of the IAC connected to MS.
The IAC is naturally set to 1/2 open, and heating the area that coolant flows through with a heat gun didn't seem to affect the valve's opening. The IAC valves on these motors are very prone to jamming/dirt/etc which means I might be also fighting a problematic IAC. The whole project is a fresh start with MS.
I feel like I am fighting a battle between how to set an idle air amount and getting the correct idle fueling. I see my options as the following:
a)leave the IAC inlet blocked off and set idle by adjusting the throttle stop
b)get a junkyard IAC and plum it in line
c)play with the IAC control in MS to get the IAC to set idle
option a is the easiest, but i hate adjusting throttle stops. option b takes too long (impatient...). option c leaves me trying to guess pwm values to get the right amount of TB bypass air WHILE trying to get my idle fuel right as well. I guess with c I get the most desirable end result.
questions as follows:
1)Should I shim/adjust the throttle stop and get the engine up and idling at a resonable RPM (~750) and get the fueling close, and then with the correct fueling play with the IAC settings to match the amount of bypass air the shimmed throttle
gave?
2) Is it easy to set up a PWM IAC to stay closed (so I dont have to plug the inlet)?
3) I'm not running power steering or A/C, do I really benefit from running IAC at all? Is the added complexity worth it?
idle control...weighing my options
Forum rules
Read the manual to see if your question is answered there before posting. If you have questions about MS1/Extra or MS2/Extra or other non-B&G code configuration or tuning, please post them at http://www.msextra.com The full forum rules are here: Forum Rules, be sure to read them all regularly.
Read the manual to see if your question is answered there before posting. If you have questions about MS1/Extra or MS2/Extra or other non-B&G code configuration or tuning, please post them at http://www.msextra.com The full forum rules are here: Forum Rules, be sure to read them all regularly.