Cycling Idle: alternating from ~2k to ~1200RPM and how I fixed it

[ABNPayne]

1. Bought a MkIII and drove it home
2. Had a rad leak so I kept it parked
3. Got tired of it sitting so I took it to my complex's carwash
4. Forgot how bad of an idea washing an 7m's engine bay was
5. Drove it to Wal-Mart later that evening, it ran like a champ
6. Didn't drive it for a day and a half(100+ temp w/ heat index), then got in one evening to go to class
7. Turned engine over and car started a high alternating idle(see thread title)
8. Got in my Oldsmobile DD and went to class pissed my new to me ride was jacked up
9. Had to figure out what the problem was when time permitted...

So I hadn't owned a MkIII for about 7 years and I forgot there was a good chance you'd mess something up if you washed the engine bay. As time permitted I did the following: Opened hood and saw a pool of red fluid that looked like trans fluid under the airbox and immediately flipped out like David Della Rocco in Boondock Saints and illustrated the diversity of the F word. I couldn't complete an expletive sentence... "What the, how the --->NSFW http://www.youtube.com/watch?v=GDQCaGlqLFY I took a deep breath and then realized that my K&N filter had bled like a stuck pig in the 100+ heat. The pool was simply filter oil that dripped from the cut open air box. I mildly cursed the prev owner for oiling it, but was relieved I didn't have to think of how this mystery transmission looking fluid came out if my intake. I cleaned MAF sensor w/ elec parts cleaner and purchased a stock paper filter.

I inspected the 5 and 6 cylinders to see how much water and degreaser I "washed" into them. Answer: A LOT! I stuffed rags into each cyl to remove excess water, called my bro to ask how to get rid of the extra that didn’t get soaked up by rags, then followed his direction to remove one or two spark plugs at a time, leave it connected to the coil pack so the current has somewhere to spark and then turn the engine over to force the remaining water out of the cylinder through the empty plug hole(s), then repeat as necessary. 4,5, & 6 are a PITA due to throttle linkage.
K, water is out. Installed new set of plugs (Denso b/c I couldn’t find NGKs near me) connected wires and fired it up. The engine promptly climbed to 2k RPM, then fell to ~1200, rose to 2k, fell to 1200…. ARRRGGGHH!!!

I searched SM and saw the common probs were vacuum leak, TPS, ISCV or MAF. I checked the vacuum lines, no unconnected or rotten hoses. I already cleaned the MAF. For kicks I start the car and remove the EFI fuse, car dies, I reinstall and start. I’m not that lucky this time…

“Disconnect the TPS” I read in a thread. OK. I then go to my car pop the hood and use a Phillips to REMOVE my TPS. I turn it over. Idle still fluctuates. K. TPS is not the problem… O crap I removed it, now I’ll just slap it back on. O crap x2, Service manual says I need a multimeter, mV, Ohm, infinity +/-, etc to reinstall correctly… Disconnect=Unplug!!

One of the plethora of parts that came with it is an extra Idle Speed Control Valve Assy. I check it out then pull the old one off. It’s pretty dirty. I need a new gasket to replace it. I call local Toyota Dealer and order gasket for ~$2.50 to arrive in 2 days b/c it was after 4 when I ordered it…
New gasket in hand I install the clean valve, grommet, and assembly. I also read here about disconnecting the neg terminal for a min or so…

For kicks I take it off, smoke a cigarette, then reconnect the battery.

Start engine and YAY, constant idle at 1k! Now i'll always wonder if the simple terminal removal fixed it, LOL

I still need to fine tune TPS and other crap, I’ll do that after I install new radiator and actually know where I’m at on MPG. Then again, if it aint broke...