plext0r

Hey guys,
I hadn't driven my 99 TL for about 4 weeks. When I went to start it up yesterday, it starts idle revving and cycling between 800 and 1500 or closer to 2K RPM. This happened on my 2003 Odyssey and they replaced the IACV which did not fix the issue. Then they replaced some plenum gaskets and the problem has gotten better. I hope to avoid any serious engine repair on this TL at this time.

I went for a 15 minute drive, got some fresh 93-octane gas, came back to my driveway and it's still cycling up to 1500 RPM. I'm not a mechanic, but I don't mind poking around trying to find some issues. What would you recommend first? I read about EGR, IACV, etc. What would you check first?

By the way, here's a video with the idle revving. 99 TL Engine Rev

EDIT: when I started it yesterday, it made a crazy noise like the A/C compressor didn't want to start, so I turned off the A/C. I've since turned it on and the idle issue goes away when the compressor kicks in.

Thank you!

01tl4tl

need to remove Throttle Body and clean the IACV, not replace it, just a good cleaning of all the parts is in order

If you want to do it right- an egr passage and port cleaning with 3 cans carb cleaner and a wire coat hanger to reach thru the length of manifold interior egr passage is probably overdue = done once years ago for the recall
that helps with overall running condition
99s have only 1 port to the cylinder for egr, later have 6, so its really easy for that to clog fast
every 75kmiles is suggested for intake manifold removal and egr service

01tl4tl

the noise associated with ac- ck the tensioner for ac belt, those fail and sound like gravel is inside
A mechanics stethoscope ($5 HFT) will pinpoint the bad part quickly

Alex D

My bet is the IAC has finally crapped out on you which is usually indicated from the erratic idle. You can try cleaning it but tried cleaning mine and it still didn't work so the actual electronics failed on mine. I ordered one from rockauto and replaced it and the idle is back to normal. I would do as suggested and clean out the EGR passage while you have the intake plenum off, you'll see the all the black gunk.

01tl4tl

good to know we are reaching the age of replacement- electronics failure of the iacv
thanks AlexD

How much was it from rockauto?

01tl4tl

cleaning the egr passage and ports inside the intake manifold is not optional-
just not getting done! We need to do clean it every 75kmiles per our mega-moderator
with 700,000 MILES on his 00TL

99s may need it every 50kmiles!

thoiboi

Check your coolant for air and replace if it's been a while since..

Alex D

In my experience on my 99 TL, 75-80k the EGR passage should be cleaned out. I've checked mine at 50k miles after a cleaning just to see and it had a little gunk built up but not enough to warrant a cleaning at that time (I did clean it out anyway since i had it apart)

The IACV I purchased from Rockauto was about $72.79 for the Airtex/Wells unit and there is always a 5% off coupon floating around the internet. I've had good experience with Airtex/Wells products in the past so its worth the premium over the other units Rockauto sells for peace of mind.

01tl4tl

I was guessing on interval for 99s, Kris recommends 75 kmiles for 00 and beyond = based on his many times cleaning it in 700,000 MILES