Idleing

[twowayparadise]

my car reves up and down like 800 to 1500 rpm randomly it will stop then go anyone know what it would be?

[imported_tegs]

Does it do it until it warms up or does it do it randomly at any temp.

[NstyGrnHatch]

yeah give us more conditions, it could be alot of stuff from what your telling us. throwing any codes?

[b series us]

it sounds like the evac..the little thing that sits on back of the intake manifold,with the two coolant lines coming from it...take it off and clean it.or it could be the fast idle vavle its under the t/b..with coolant lines from it u can take it off and clean it,or u can just block off the 2 ports.to do that u can use jb weld on a stick....or it could be a good vac leak...let ur car run and spray crab cleaner around the t/b and manifold,and any hose the has vac,and if the car dies down when u spray a cert,spot then u have a leak...and all u have to do is fix it

[Smooth_Imports]

Originally posted by b series us@Mar 7 2005, 08:28 AM
it sounds like the evac..the little thing* that sits on back of the intake manifold,with the two coolant lines coming from it...

It's an IACV (Idle air control valve)

.or it could be the fast idle vavle its under the t/b[/b]

Not all cars have this, my LS swap doesn't have it,





On another note i'm having the same problem after the swap, I'll still looking into a solution to fix it.

[sleepinsol]

ok.. its still idles the same.. it will stop for awhile idles good then it will start reving up again i tried moving the bolt on the imf but that just changes what rpm to idle. im going to see if there are any hoses not hooked up.. also that container thats hooked up to the hose that goes to the raditor is empty... i looked at it and theres not a drop.. but there is raditor fluid i think cause the shop i just got it from got it running and changed everything oil.. brake fluids etc. i will keep everyone updated.. sooon to take pics

[Toyz-B-Us]

Besides the IACV, it could be in the throttle body or the throttle body gasket. I would recommend buying a new gasket and while the tb is off clean the crap out of it, make sure that your butterfly is still screwed tight and centered properly. I also would clean the idle circuit with some carb & tb cleaner.

[NstyGrnHatch]

might need to refill and bleed your coolant sometimes air gets trapped in the IACV valve and can make it sound like its going bad, do that, if thats not the problem diagnosis the IACV valve or Fast Idle Control Valve.

Oh and on a second note: IACV's are NOT cleanable. At least with brake cleaner.

[dubcac]

Vacuum leak
IACV
Fast Idle Thermo Valve

[NstyGrnHatch]

yeah go with the cheapest first. then move up.