high idle (sometimes)

mtndew · 06-13-2009, 07:06 PM

ok so sometimes my 92 1.6 8v will want to idle around 12-1500 mostly when i have been driving alot and stopping and starting the engine. also when i start it, pretty much every time i start it that it doesnt idle high it idles low, at around 500 but once i start driving and come to a stop it usually idles closer to 800 but still not quite (it takes it a lot longer to normal out if its idling high, if it goes down at all).
anyone have any ideas on what to start checking and how if its something electrical. i think i need to adjust the idle too but i cant do that until i find out what else is wrong.

jtgh · 06-13-2009, 07:21 PM

im kinda sure ( as best online as possible -weak) your isc is bad.

mtndew · 06-13-2009, 07:38 PM

it does get hot, dont have a temp gun or anything else to measure but it is hot to the touch, the dp doesnt hold it quite that long, id probably say 2000 for 2 seconds. havnt checked for vac leaks but im pretty sure there arent any, and i dont have a timing light

but that is one of the things ive been meaning to check since i got the rig. so i guess ill just check all those things and see where im at. if all good, then its good to adjust idle screw?

jtgh · 06-14-2009, 01:13 AM

ISC

there is a huge section in the FSM on that. i will look....

mtndew · 06-14-2009, 04:02 AM

ok, first off, would it be easier just to start with the isc (btw i have efi, no carb)? and second whats involved in cleaning the isc? do i have to remove it? i know in my miata i have to pull the throttle body off to take of the isc to clean. is this similar? and last,

Quote:

the idle adjust in the air bleed on the TB,front of air horn. has rubber cap.

im not sure i quite understand what your saying here, and my car has an air horn? i thought it was just a regular car horn (wouldnt mind having a compressor powered air horn tho >

)

mtndew · 06-14-2009, 04:05 AM

also on a completely different note, i think my rig is an 8v but dont know for sure. how do i tell?

jtgh · 06-14-2009, 12:56 PM

im not sure either.

jtgh · 06-14-2009, 01:08 PM

if you dropped the isc and covered the holes the car will idle real low.
that shows for a fact you have no air leaks.

dropped means removed. and blocked.

mtndew · 06-15-2009, 05:05 AM

awesome, and one last question. where besides dealership can i get an iac gasket? none of the parts stores around here can get it. can i just make the gasket?

jtgh · 06-15-2009, 01:47 PM

ISC on your car is bad.
or
something far more complex ..

i will not elaborate on that....