Intake Air control valves

[Roert42]

Question is specifically about a 4.0 sohc engine, but I suspect it shouldn’t matter.

Do these only go on one way or could I flip it around? physically it will bolt in 180 out.

Does the plunger have to be before or after the throttle plate?

I had it installed with the plunger after the TB plate, but the wires for the connection were rubbing on the housing for the blower motor.

 

[RonD]

I don't think it would work well flipped around

One port is from the front of the throttle plate with 0 or low "ported vacuum"
The other port is on the intake side of throttle plate with 18 - 21" of vacuum at idle
Its a Solenoid type valve, not a stepper motor type valve

Current position means vacuum is trying to pull the valve open to let in more air, the solenoid is pushing out against this pressure to reduce full air flow

If it was flipped around then vacuum would be trying to pull the valve closed, the solenoid should be able to pull it open but not sure, idle would be the challenge

It would also confuse computer, lol, but it could probably adapt

 

[Roert42]

Figured that would be the case. Sounds like I’ll need to find one that has a straight connection rather than a 90.

 

[Roert42]

For the record.

It’s idles around 2k rpm with the IAC valve installed backwards. If I blip the throttle it will drop down to about 1500 the. Slowly work it’s way back up.