AO

I know you're hesitant to re-pressurize your setup, but i think that's the way to do it. You don't need a ton of pressure, 15psi should suffice. Then use a rubber hose to listen down int eh valley. My guess is you'll find your leak pretty quickly.

John Speake

Have you checked the idle vacuum on one of the fuel dampers ?

aggravation

I have a boost gauge in the center console, it gets it's vacuum/boost feed from the vacuum lines that feed the fuel pressure regulator and the two dampers.
It reads 20 in Hg until it starts making positive pressure in the upper rpm's. The only other thing on that unchecked series of vacuum lines is the blow off valve for the supercharger.
I pulled the vacuum line off the front damper and there was no change, vacuum was definitely present at that point.

On the checked side of the vacuum system it holds vacuum for days, weeks even.

aggravation

Ok, I'll go back down that road if I have to but wouldn't you think the starting fluid would have done something?
Is there any other component I've left off that might introduce unmetered air?

Does anyone know the proper torque specs for the intake manifold bolts? I lubed the rubber grommets and used a torque spec I found somewhere but it wasn't clear that it was the intake to throttle body or the intake to heads....maybe I just didn't get the damn intake bolted down tight enough! It doesn't look like it squished the edges of the new gasket at all...then again the old gasket didn't look very squished. The rubber grommets on each manifold bolt are deformed a bit from tightening but not nearly as bad as the old ones were.

Could the O rings on the injectors allow air to enter the mix?

AO

Torque spec is only 11ftlbs. Be careful - don't over tighten.

aggravation

OK I pressurized it and I can hear that same old sound of a low pressure hose filling a large tank and no other sound of air leaking anywhere.
What I need to know is, if your car had no leaks and you pressurized the MAF inlet with about 12 psi what would it sound like and how long would it take to empty a 15 gallon air tank?

My tank, at 120 psi, output regulator at 12psi, goes empty in about 20 minutes, I hear that sound of air going somewhere, I assume past piston rings into the crancase. Is this normal?

AO

Right... some air will get past the rings and pressurize the crank case, some may even get past the intake valves and exit out the tail pipe. What you need to do is take a length of hose and listen all over for air leaks.

aggravation

Yea, sorry, I should have been more specific. I did use a 3 foot piece of fuel line, one end in my ear, the other poking under the intake every way I could....nothing. I'll try again tomorrow with a touch more pressure but it's starting to look like it isn't there.

Is there any internal mechanical condition that could give me the high idle?

AO

Do me a favor... pull your plugs and photograph them (Use the camera's Macro setting to get a good focus). I know it's a PITA, but you'd be amazed at what plugs can tell you.

If there is a variance in color it could be a particular cylinder that's giving you issues or coil, etc.

Also, if you can, double check the two ground points on the rear of the engine near under the air box, near the shift linkage. Your LH harness gets it's ground from here. If these are loose it can cause the injectors to not fire (sudden loss of power) which would show as lean because there's no fuel.

hacker-pschorr

Also check the smaller wires on the battery terminal. IIRC those directly feed the LH.

aggravation

Thanks guys!
I checked those grounds right before I put the new intake on (the symptoms were present both before and after the intake R&R) and the grounds were not loose. I didn't loosen and clean them because they looked good with no sign of corrosion etc on the exposed part of the connection and so I didn't want to disturb them.

I will go and pull the plugs and check the battery connections right now....

hacker-pschorr

We had an S4 up here doing some strange things under cruise - it was those wires on the battery.

Check your voltage at the LH next, make sure it's receiving full power.

aggravation

Just check it while the car is off? Ignition on? Engine running?
Where to put the test leads to read the voltage...disconnect the big multipin connector and check there? Do you know which pins to check.... or maybe just check at the diagnostic port at the LH?

aggravation

Ok, I took the two pairs of smaller wires off the positive battery cables connector and checked them...no corosion, no sign of cracking or other damage. They were tight and the terminal has dielectric grease on it.

Still haven't checked voltage at the LH, waiting on directions how to best check it...

Here's a pic of the plugs, I have more if you need it. They are laid out in the position they were in the engine.



Thanks for any help!

aggravation

OK, I did a compression check since the plugs were out.
1- 182
2- 172
3- 180
4- 180
5- 185
6- 183
7- 185
8- 190

Each cylinder started by reaching 120-140 psi on the first stroke and each following stroke advanced the pressure at least a few psi
This was with the engine cold. Seems pretty good based on what I've been able to learn.
I disconnected the coil primary wire from term 15 and pulled the fuel pump fuse, I guess that precaution was all that was needed because I don't smell fuel and there was no spark...

Still hoping for advice on how to check voltage to the LH to see if it might be the problem...
And on that thought, the SharkTuner registers voltage in it's log, mine shows a solid 13 volts all the time...is that reading the voltage supplied to the LH or not?