…IT IS SOLVED! Oh my F#$KING GOD! Finally! Only took 1.5 years of poking and prodding. I’ve got tears-of-joy rolling down my eyes.
Ok, here is what I did:
That spare TB I had from my parts car tear down got a nice sandblasting this morning to clean off all the crap. So it was all clean, it looks really good actually. Just needs paint and/or powder-coat, but I didn’t have time for that. So it was ready to go – I took off the new IAC and the TPS off the old TB and hooked it up to it.
I inspected all the lines going into the TB, everything looked good. No cracks, etc. etc.
…Now, …even though I threw a different TB on, this is the area I believe that was causing the whole problem:
…that small piece of rubber hose connecting the metal TB vacuum line to the lower intake – that extra play was not creating a good enough seal. I did a “poor-man’s” test, and took the metal vacuum line (while un-hooked from everything), plugged one end with my finger, plugged it into the rubber hose, and then I blew (like filling up water-wings) into the rubber hose, and I could still blow because there was a leak (a.k.a no seal) between the rubber hose and the metal vacuum line. Lo-tech way of testing it, …but hey, it worked. If I could blow and cause a leak, then I know the engine suction would definitely allow extra air in.
So, I took a trip again over to the local auto store and looked for a tube to match the dimensions, …or smaller if possible because of the extra play. Nothing. So, I picked up some hi-temp sealant, to deal with any extra play area that might cause a vacuum leak – rated at 231 degrees temp, figured since I’m not putting any fluid thru this, that should do the trick. I also picked up one stainless steel tightening bracket – standard type for hoses.
I came back, put sealant on the lower intake part of the rubber hose, …put it on, then twisted it 90 degrees so the sealant get all the pipe. I put sealant on the metal vacuum line end, put in into the rubber hose, twisted it slightly. Then I attached the metal tightening bracket and tightened it. The bracket was used to tighten the metal vacuum line going to the TB only. I put the throttle body on, attached all the vacuum lines. Put the cold air intake on, and let it set for one hour. The sealant needs one hour to set – figured I would follow instructions and wait.
Went out, and fired her up. It began to idle at the 1500-18000 rpm level, it sounded far better than it normally does. It stayed there for about 3-4 minutes, which I began to think “f@#k, not again”. I had the deck-lid off, so getting up to operating temp probably took just a little bit longer. Once she reached operating temp, the rpms dropped to about 1400, then 1200, then it finally came down to 950-1100. I’m not sure exactly what the RPMS were because I haven’t done any ALDL tests – but she sounded normal again. Brought a tear to my eye, …been pissing around with this thing for so long, it seems. I guess a a year and a half is a long time – but I only got serious about the problem for that last 4 weeks.
One thing I tried was giving it some gas, and the rpms went up, then came right back down to the idling level :) – that is one thing that it wouldn’t do before becauee it would come back down to 2500 rpm. When I would take it out for spins, it could shift from a standing point because the idle rpms were high enough to get into first gear (without touching the gas) – with no stalling. I haven’t taken it out for a spin yet.
Oh, just to let you know, the TB screw on the TB attached now HAS been tampered with – a.k.a. no seal :( I’ll have to take a look at it further, but I’m almost to the point where I don’t want to touch anything because she works. I need to paint the TB anyways, so when I pull it off, I may take a look at this further.
I need to take it out for a spin, but I’ll let you know how it goes. I may go this afternoon, but I need to reattach the decklid. That may be tough to put it back on, because I’ve got massive back-pain (no joke) from bending over the engine bay for the last 3 weeks.