My car is down for a few days, sent my PCM off for a tune. While she's down, I decided to take the TB off and replace the IAC and TPS and also clean it up. This is what it looked like:



I though that was oil pooled in there, but it was real sticky, maybe partially dried up oil. Is this normal? I removed the plate on top and found this:



The hose attached to this goes to the back of the passenger side valve cover. It looks like a PCV valve, but the PCV is on the drivers side, right?

Looks like my intake plenum could use a good sea foaming:



Here is the new IAC and the old IAC....the new one is much shorter....is this an issue or does it move where it needs to once it is hooked up and the engine starts?



Think I could put one of those breather filters on the valve cover and disconnect this hose completely to keep from sucking this crap into the intake?

 

Soak that tb in some simple green and water, about a 50/50 mix, for like 5 hrs. Than with a good pressured garden hose clean everything out.

 

looks like pcv valve is failing forcing air back into the tb. air through that hose is supposed to be going toward the valve cover. do you have a aftermarket air filter?

you need to set a new iac on install, ill have to look a minute to find the directions.

 

shoulda known, shbox 4th Gen LT1 F-body Tech Articles

and yah if your pvc valve is not failing then you got some blow by coming from somewhere, rings maybe.

 

I've got a k&n cai. I was going to get a couple of breathers and put one on the tb where the hose coming from the passenger side valve cover attaches and then another breather at the valve cover and just remove the hose altogether. That way the tb gets fresh air instead of sucking the oily crap from the valve cover and let the valve cover vent to atmosphere.

 

That hose from the valve cover to the TB is a crankcase vent, where vacuum pulls in the fumes for the engine to burn it, instead of fumes going into the air. That gooey build up shows that you have a little bit of ring blow-by, which causes oil to be mixed with crankcase fumes. If you remove that hose and put a breather in the valve cover (old school style), then you need to cap off that open vacuum fitting on the TB.

 

dont leave an open air intake at the tb, plug it.
if the k&n filter was oiled and not drained, the oil will get sucked into the tb and look like this. blown head gasket or cracked head can also do it.

 

Gotcha. Of course, this is probably the first time in 19 years and 190,000 miles that the thing has been opened up. I will clean it real good and keep an eye on it. I dont burn any oil.

Oh lord, please dont say that....I would hope there would be other driveability symptoms associated with a cracked head or blown headgasket....

 

Naaaaaah, yours just looks like it's a build up of oil and varnish that took many years to get there.

 

The beast lives! Got my PCM back yesterday (been gone over a week). Man what a difference. Had some issues with the idle, turns out one of the wires on the IAC connector broke in half, right at the connector. Of course, parts store did not have one in stock. Managed to strip it back and solder it back together as a temporary fix. Also was idling high, had to back the idle stop screw way in to get it down to where it was supposed to be. I believe this is because of the thorough cleaning I did on the TB. It would never idle right before and I had to adjust the idle stop screw out to raise the idle. Before, it was idling about 1500 RPM's and the IAC position was 0% and it was calling for 800 RPM's. Now it's idling at @900 RPM's and the IAC position is around 2-3%. At least the IAC is controlling the idle now.