Pulling the Plenum for the first time...

[Kevin]

Originally Posted by Billy Mild

My vacuum pump runs for literally 1 second then shuts off. The system appears to be pretty tight as far as that goes. It doesn't seem to leak from that aspect. Everything was ZIP-Tied and and any pieces that didn't seal well with a vacuum pump were replaced.

I have leaking fuel from under my plenum. It didn't do this the night I got the work complete, and it didn't leak yesterday. It must have done this overnight. So I guess the plenum is coming back off?

I know I have a vac leak that I just haven't dealt with yet and my pump does the same thing

[Billy Mild]

Originally Posted by Kevin

I know I have a vac leak that I just haven't dealt with yet and my pump does the same thing

If I did have a vacuum leak, wouldn't the idle be fluctuate all the time? I just don't see who it could be leaking. I have used a vacuum pump to check all the connections and nothing seems to be leaking.

[Billy Mild]

Here is a little video of what I am dealing with when the car is fully warmed up.

http://youtu.be/TjD4C59Q9gA

[Billy Mild]

I had a suggestion from Marc Haibeck that it could be the PCV grommet for the valves. I checked that today and it was ziptied to the tops of the PCV valves. Is there anyway to pressure test that system?

Another thing I noticed today. If the AC is on the idle is pretty much perfect. It doesn't fluctuate at all. Is that normal? Could this all be IAC related?

[XfireZ51]

Originally Posted by Billy Mild

Another thing I noticed today. If the AC is on the idle is pretty much perfect. It doesn't fluctuate at all. Is that normal? Could this all be IAC related?

That's because the AC put a load on the motor and moved the idle to a different/richer part of the VE table. Suggests to me that your oscillating idle is due to a lean surge. The VE table at idle needs to be flattened out, probably along w the SA table altho I would look at Closed Throttle Idle SA setting.

[Billy Mild]

Originally Posted by XfireZ51

That's because the AC put a load on the motor and moved the idle to a different/richer part of the VE table. Suggests to me that your oscillating idle is due to a lean surge. The VE table at idle needs to be flattened out, probably along w the SA table altho I would look at Closed Throttle Idle SA setting.

This sounds like a tuning issue. My car is pretty much stock minus the K&N air filter, and the center resonator delete and borla mufflers. Would that cause a lean surge at idle? I would think the stock FI system could handle those changes.

[Billy Mild]

Any idea on what to look at?