About the Intake Manifold Runner Control (IMRC)

Just from my experience I'd like to share a bit about these little guys:

If you get CEL codes for IMRC, then it might be a few of the following problems:

1. IMRC are bad
2. vacuum is bad
3. IMRC butterfly valves are stuck.

You can easily test the #2. I did and ruled that out.

When changing the lower intake manifold, I noticed that the IMRC butterflies are filled with gunk, thick gunk of several mm thick. :uhoh: I spent quite some time cleaning them out and after that, the IMRC works perfectly.

So my suggetion is that if you don't wanna shell out $600 buying a pair of IMRC, you might just open the intake manifolds and clean the crap out. If it works it works.

Where are these items at and how did you check for vacuum???I keep getting this code (P1520) bUT IT RUNS FINE.Sometimes I smell a little gas at idle too. Thanks

Good info!

But keep in mind that as of '99 the runner control went to electrics ... no vacuum anymore.