LOCATION OF AIR BYPASS VALVE

[gaz]

Hello,

I went to the wrecking yard to hunt down a replacement lower air-box; they had several 4 cylinder Rangers but no 2.9L so I looked at their air-boxes. For the most part, they are the same.
DIFFERENCES:

1) some ½" tube connection coming off the front
2) the air bypass valve (ABV) is mounted to outboard side of the air-box lid.

Why do you suppose they put the 4 cylinders air valve on the air-box lid verse the intake manifold? I want to move mine to the air-box, blank off the manifold port and see what happens ..)

I think that the computer will see the lower temperature and raise the idle, which I do not want but am curios.

 

[RonD]

Never seen that type of setup for IAC Valve before, its doable just never seen it done that way
May have been done that way prior to new throttle body design was available during EFI change over

The air TEMP sensor can be in the air cleaner box or on the upper intake
Might be a little cooler in the air box, but maybe not
The air box is separate from warm engine, but.............it also doesn't have same air velocity
Upper intake will have engine heat transfer but alot of air velocity inside

Air temp doesn't set idle, coolant temp does, via ECT sensor

 

[gaz]

RonD,

That air box came out of a 1987 extra cab 4x4, I4 Ranger, 2.3L. It may be that there just wasn't a great location on the intake manifold.

Once I have all the bugs worked out of my engine I will swap the IAC to the air box location, blank-off plate the intake manifold location and see what happens.

 

[Dirtman]

I dont even understand how the iac valve can function there? Where/how is it actually putting air behind the throttle plate?

 

[RonD]

Yes, you will need a port on the intake to hook up the 1/2" hose from IAC Valve
A "T" on the PCV valve hose or Power brake hose would work