Pulling the Plenum for the first time...

[Schrade]

Originally Posted by Billy Mild

In general the car didn't run very well before this work. But it did have a consistent idle.

Now the car runs better, much better, but the idle is not consistent. As far as I can tell there aren't any vacuum leaks. I tried spraying potential vacuum leaks with WD40.there was 0 change.

Could be TPS or IAC possibly?

You boosted RPM's before spraying for a leak?

Originally Posted by Schrade

FIRST (fully warmed up motor); block the gas pedal, or block the throttle linkage. YOU HAVE TO DO THIS TO GET A STEADY IDLE , around 1,250 rpms, or a little higher. If you don't, you can fish starting fluid, a propane hose, or WD40, or Krylon, or hair spray, or pee, anything, until you need a sweater in Hades, but if the motor is lopin' idle already from a vacuum leak, you ain't gonna' find any leak, unless it's so big that Little Jack Horner can stick his thumb in it and pull out a pineapple NOPE.

AFTER you get a steady idle, THEN, you can spray starting fluid everywhere - that's the best detector, because it's vapor pressure is very high - a LITTLE at a time, all around the motor, until you get the rpm SURGE. Follow the vacuum lines to the EVAP cannister too. You might even have to follow the EVAP lines from the EVAP cannister to the gas tank too, but that vacuum leak will show up as a DTC 32 EGR fault, and won't normally show as loping idle, unless the EVAP cannister has been by-passed (been there, saw that uh-HUH yup).

If you get a surge in a tight spot, and can't tell exactly where it is, light a book of matches, blow out the match heads while they're still burnin', and feed the smoke to the tight spot to see it get drawn in.

Fear not the starting fluid; you cannot put the can down fast enough and light the matches fast enough to catch the starting fluid, because the vapor pressure is so high.

Short of that, the phone book trick like mike100 said worked for me @ TE Cleanup. I had forgotten to put a clamp on the PCV's rubber valve cap-to-pipe connection, behind plenum, and it was sucking air.

After that, it was ROCK steady 675 (with the TB 2' gasket block, which told me that all else was in perfect tune order).