hihopes

iTrader: (7)

Alright so upon start up, my sc300 idle jumps up to 3k and doesnt go down at all. Let me give some history.

I was leaking oil out of my cam seals so i replaced those, valve cover gaskets, spark plugs, and pcv valve while i was in there. Got everything back together today, the only thing that wasnt set was my ignition timing.

I start the car and get my timing light ready and the idles jump up to 2500 and were very slowly climbing on their own. I let it warm up for 3-5 mins and there was no change so i shut the car off. Checked all hoses, plugs and everything. All looks good so i start the car up again and it starts at 3k and i see it still climbing. Sprayed some brake cleaner around the vacuum hoses but could not find any leaks.

My car ran perfectly fine before all of this, besides the oil leaking. Nothing was adjusted, so im not sure why my idle is so rediculously high out of nowhere.

RedMansSC3

iTrader: (3)

Since you removed the TB, I would just look over the small things like is the spring sticking on your throttle links or maybe one of the hoses has a crack. Then go to some of the not so likely but still possible like TPS got budged and now reading out of range?

hihopes

iTrader: (7)

The throttle cable seemed to be working properly when i would blip it. There was a little slack in the cable, so i tightened it a bit, but that didnt help at all. Ill inspect the spring to make sure its not stuck.
Hoses are all good, those have all been checked out.
Ill check my tps too and see if thats the problem.

I just find it weird how it slowly climbs, instead of slowly going down like it would normally do while warming up

RedMansSC3

iTrader: (3)

agreed, Thats why it sounds like something like the springs, tps, or iacv is sticking or out of range.

SC400slide

iTrader: (11)

Sounds like a sticking IACV.

hihopes

iTrader: (7)

cleaned out my iacv, springs working fine on throttle, tps seems to be fine.


I took a video of the start up this time. Jumped to about 2500 this time instead of 3k and once again started rising. Also found a crack in one of the hoses going from the pass valve cover to the air tube when i took the throttle body off again. Would this crack be causing such a high idle?


Dont mind the cel, the only codes are from my manual trans swap.

t2d2

iTrader: (8)

Every time I find a cracked hose like that, some of them resulting from recently done work and being too brittle for re-use, replacing it helps with vacuum related issues. Most of them can be replaced for a shade over a buck a foot at the auto parts store, so it's definitely worth doing as a quick test.

Ali SC3

iTrader: (10)

wiggle the wires on the IACV valve, possible you have a cracked connector. there are many small things that can leak when doing the valvecovers since you have to remove the throttle body and the "Y" portion. If that hose is cracked it can surely let in extra air or even the PCV hose on the other side I would check that since it comes in after the throttle body and replace all suspect hoses, especially like the one shown with a long crack/tear.