Another ISR mod thread
 

I am looking into the ISR mod and have a question.

There are two hoses coming from the air box & silencer components that connect to the metal harness that runs across the front of the intake plenum. The larger hose appears to pull filtered air before the VAFM for the pair reed valve. The smaller hose appears to pull air after the VAFM for AC and PS idle up functions (I read that having used the search feature prior to posting J)

When considering the placement of the fitting for the smaller hose that draws metered air, does it have to be placed AFTER the VAFM or can it be located on the air cleaner box before the VAFM? The difference is that it would be filtered but not metered at that location.

Most place that fitting on the intake tube after the VAFM…, just wondering if that is required.

Thanks,

WJ

From what I have seen others do it ends up not being metered and placed after the AFM in the newly modified piping. That's where I'll be putting mine when I get around to it.

If you put it before the AFM, the computer will not know about the air put into the plenum when the AC is on or the PS valve is open. This will be like a fairly significant vacuum leak and will cause a lean condition.

If you plan to leave the AC and PS idle up systems intact then you should put the hose after the AFM.

Bugs1961,

That is what I needed to know. While researching this, I read a really informative post of yours in a previous thread on this subject as well. Thanks for taking the time to help out.

WJ