IAC/Angle Boss question

[QuickWE4]

Hey guys:

Well, with all the snow on the ground, it's a great time to install my Angle Boss. Question: I know that the computer controls the IAC. Thus, if it's set correctly in the current setup, will I need to reset the IAC after installing the Angle Boss?

TIA
Rich

 

[strikeeagle]

Of course minimum air has to be reset. Think about it. You've just modified your TB. How can you be assured that the IAC, having been removed and installed into a completely new housing, will allow exactly the same amount of air to bypass the throttle plate as it did before? Unlikely.

 

[QuickWE4]

Ah. Makes sense.

Thanks Strike...


Rich

 

[James West]

Yes, you will have to reset it. I have one on my GN and it works perfectly.

Originally posted by QuickWE4
Hey guys:

Thus, if it's set correctly in the current setup, will I need to reset the IAC after installing the Angle Boss?

TIA
Rich

 

[Roger]

I did mine the same time I installed the RJC power plate & had to open the IAC a little, indicating I had a small leak before.

 

[Matt Weiser]

So does this mean the TPS will have to be reset, too? Aren't the two settings somewhat dependent on each other? Just wondering as I may be installing an angle boss and power plate, too.

 

[strikeeagle]

Maybe.

Let's demystify IAC and TPS.

When somebody says they're going to adjust IAC, what they really mean is that they're going to set minimum air, so that the IAC falls within a particular range of values.

Turning the minimum air screw in (i.e. clockwise) opens the throttle plate, allowing more air through the TB, lowering IAC and raising TPS. Conversely, backing the minimum air screw out (i.e. counterclockwise) closes the plate, raising IAC and lowering TPS.

That's all there is to it. Other than to say you need a scan tool that reads IAC and TPS.

The chip establishes idle RPM, unless you've screwed up and turned the minimum air screw in too far, and it "takes over".

"Mechanical" problems, such as vacuum leaks or the throttle plate not sealing in the bore, as can be the case with some aftermarket TBs, can also mess things up, causing artificially low values of IAC. Think about it. Leaks have the same effect as increasing minimum air.

Another "mechanical" problem to be on the lookout for is a weak or dirty IAC or dirty TB.

Make these adjustments when the car is fully warmed up. Some guys make their adjustments with the car in P, some in N, some in D, with the help of a buddy (don't get run over). Whatever.

Turn the key off to reset the IAC (the pintle will retract), as needed.

Check the values, once, twice, three times. Then drive the car a bit, and recheck your values.

Set WOT TPS with the car not running (good idea).

It's just that simple.

End of mystery...