Originally Posted by Billy Mild (Post 213585)

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?

Originally Posted by Schrade (Post 213603)

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.

Originally Posted by XfireZ51 (Post 213606)

The LT-5 sucks so well at idle that it doesn't take much to have a vacuum leak.
How often does your secondary throttle vacuum pump come on w key ON?

Originally Posted by Billy Mild (Post 213614)

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?

Originally Posted by XfireZ51 (Post 213615)

BTW, the injector O-rings, if not seated properly, can be a cause of a vacuum leak. Were they removed earlier? Good idea to use some sealer where the injector O ring seats in the housing.

Originally Posted by Billy Mild (Post 213654)

I replaced the injectors and all the associated o rings with brand new ones. It appears the one injector o-ring got pinched which caused a decent sized fuel leak. The only thing that was weird is it just started to leak Sunday night. All this work was performed on Saturday evening. I have remedied this leak. I also used 2 stroke oil when I put the fuel rails back in.

I am working through getting everything that would possibly leak air ziptied very tight.

Originally Posted by Schrade (Post 213701)

Been there done that.

Dropped a socket (ask Paul W on the particulars), and had to pull the INJ / rails. Gas dried a lubed O-ring, and it sheared off nice and clean on rail re-install. Fuel LEAK!!! And AFTER one successful FP test GRRR

https://lh3.googleusercontent.com/-M...0/HPIM7496.JPG

Originally Posted by Billy Mild (Post 213713)

Almost exactly what he failed ORing looked like. I was pissed. Thing is the leak didn't show up until a 36 hours later.

So I drove the car this morning, look like my coolant tank is leaking just a wee bit. Need to put some more JB weld on it again. Other than that the car ran smooth. Before the car was fully warmed up the idle would go up a little bit and back down.

Originally Posted by Billy Mild (Post 213614)

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?

Originally Posted by Kevin (Post 213754)

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

Originally Posted by Billy Mild (Post 214165)

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?

Originally Posted by XfireZ51 (Post 214167)

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.