IDLE WAS ROCK SOLID - Now it isn't as solid? What could this be?
 

Alright, Had engine rebuilt, and everything was rock solid with the FC, took it from Phoenix, to San Diego. After putting 1000 miles on it without boost. Now the idle is a bit jumpy, not real bad, but idles a bit lower than it did before, and it jumps around +/- 20rpm are so, slight movement, and a few hickups i can hear, but it WAS rock solid.

ANy ideas on what could cause this?

Thanks,
-Darren-

Usually a vaccum leak. You know what to do man. Off goes the x-over pipe and strut bar - start looking around the vaccum-tank.

Also, I know you recently got a PFC. Since you just broke in the engine, I would reset the PFC again.

yeah reset, no change... vac leak eh.. .i thought it might be that... hrmmm disconnected hose most likely...?

DAMN HOSE!

Did you reset the PFC and the let the PFC "learn" the idle again? (45 mins)

Darren,

No real reason for it to just happen out of the blue. What does your PFC show for vaccum at idle?

Short of chasing a vacuum leak, I don't think theres too much you can do. I'd be happy with a +-20 rpm jump though.

Also remember Darren, the lower the engine idles the more inconsistent the idle will be.

How much of an idle drop are we talking here?

Mine is typically around 880 w/ around 20-40 rpm variance (8.5 lb flywheel/stock port).

So reset the PFC and let the car idle for 45 minutes???

I am saying that the idle was rock solid at 900, if you looked at the gauge, it didn't move an inch, now it's moving a bit, every so slightly, but enough to make me wonder why it's not as solid as it was.

Sure it takes 45 mins to learn the idle??

Takes 30 minutes.

10 normal.
10 defrost on.
10 a/c on.

Did you get it ported? If you did then the idle will be lumpy.

R.K.

Well idle would have been lumpy when it was going through the break in right? Only thing ported is the wastegate.

I'll reset the PFC again and turn it off, then start it back up for 30 mins see if it adjusts itself.

-Darren-