I have a 2003 TL3.2 Type S (109k miles) that has been in storage (garage) for 18 months. The battery was expectedly dead, but after I put a new one in, the car started and ran at about 1500 rpm. After it warmed up for a few minutes it idles down to 600 rpm, then back to 1500 rpm, revving continuously. That only happens in park or neutral, when I'm driving it down the road, the pedal is sticky and holds the car at about 1500-1800 rpm anytime while in drive.
The VSA and ! lights come on randomly, but to get them to go out, I turn the car off and they don't come back on initially. The car shifts a little hard, not sure if its because of the higher rpm? Acura replaced the transmission (no charge) at 68k miles.

Thoughts?

 

Sounds like the Honda idle of hell. If the TPS(throttle position sensor) says that the throttle is fully closed and the RPM is >1500, the car will shut off the fuel injectors. Then, when the RPM drops low, the fuel injectors will bring the idle back to 1500. This will repeat forever in idle.

That's the symptom, not the problem. Your having a rough idle, and that could be caused by many things. Getting your codes read would be a smart place to start checking though.

 

since it threw warning lights it has stored some fault codes- parts stores anywhere except Ca, will read them for free

chances are after sitting there its gelled the fuel- thats gone thru and clogged some things
so now needs some good fuel cleaner- redline or seafoam would be best for this job
full can or bottle to half a tank
PLUS
the IAC idle air control is likely carbon loaded and crudded- number 1 cause of erratic idle
remove Throttle body from engine and its under the cover on bottem of TB

May as well do the whole job right by removing the intake manifold and cleaning the EGR port system, it clogs up too and causes many problems
2 hours at a very casual pace for both jobs by someone new to working on cars,,the TB attaches to the manifold- see DIY

 

WRONG! Usually a idle like that is caused by the IACV (idle air control valve) Usually taking a car that has sat for a period of time and take it out and drive it for a while will clear it up. If not you may need to clean the IACV.

 

Just a suggestion, you should check your vac lines as well. I had this constant (800 - 2000rpm bounce) and my problem was due to an unplugged vac line

 

Thank you everyone for the insight. I took the car to the Acura dealer in town and it ended up being a failed idle air control motor (P0505 idle circuit malfunction). They said all the issUes were tied to that. $125 for the diagnostic and $335 for the replacement of the idle motor (total $460). They did suggest I do the timing belt replacement for $1,150 but I didnt . I want to see If the car is fixed and worth keeping first...lol. THANKS!!!

 

I did learn that storing a car for any period of time in a unheated garage is not good. $460 for the Idle motor, $130 battery and $1,300 in rims and tires (total $1,890) is a spendy lesson. But...it's all new now!

 

Like I said, that was the symptom and not the problem. The problem was the IACV.

http://www.youtube.com/watch?v=AMjQry8mz-E

 

Anybody know if the IACV gasket or orings in there are fragile. Autozone and other auto part stores cant get the gaskets. I need to clean mine but dont wanna mess them up.

 

Freaking dealers... Since you got the work done with them, they should of waived the damn diagnostic. I know my dealer would of.

 

Why not start with what is most common on the TL. The symptom he described WAS the exact symptom of IACV on these cars.

 

Trying this tomorrow.

 

Didn't start there because I didn't know that was it. I'm not as experienced/knowledgeable as you. Just explained why the idle does that cycle, as that's the only relevant information I could credibly offer.

 

When taking off the cables on the tb, is there a certain arrangment I need to keep or is there a trick?

 

Just remove the 2 inner nuts on both cables.
Do not move the 2 outer nuts ;use them as markers
when you put them back.

 

feel the amount of cable freeplay by pressing down with thumb
Rotate the throttle assembly so cable pops up- then slide ball/cable out of slot
lube those return springs while you are there

the TB to manifold gasket may tear (clean TB air plate while you are there)
the IAC cover gasket is usually ok,, but its always wise to have both on hand
if you can wait for dealer to get them
grab a couple cans of non chlorine carb cleaner too