My 95 honda prelude 2.2L idles high and low when it's cold. after it warm's up rpm's drops to normal. can anyone give me a tip?
2007-01-11 16:10:25 · 6 answers · asked by L.A 1 in Cars & Transportation ➔ Maintenance & Repairs
Preludes have a tendency to idle erractically. Your idle probably bounces from 800-1200 RPM or anything in that range back and forth right? There are a number of things that could possibly be wrong.
You can have air bubbles in the coolant. Bleed the coolant. Leaving the radiator cap off, turn on your engine, and loosen the bleeder valve screw. To find this, follow the upper radiator hose to the water neck, there will be a mess of sensors hooked up right after this, the bleeder valve is the 12mm (I think) bolt with a hole in the middle of it. Keep this valve open until pure coolant is spilling out, no air at all, then tighten it down. Top off your coolant again, and run your car for a bit more w/ the valve tightened and the cap down. Repeat a few times until all of the air is out.
It could also be your Idle air control valve.
Cleaning out the IACV and reinstalling it does help some with the idle.It is connected to the front of the intake manifold and on top just above the fuel rail.
You should try screwing in the screw on the fast idle valve... Flat Head, located on top of the Throttle Body. If that's screwed in all the way and your still having surging... you could either have a bad fast idle valve, still have a bad IAC (even though it's clean now, the motor can go bad due to the gunk build up inside causing it not to work properly over time), or even have a NICE vacuum leak. But I doubt you have vacuum leaks because the idle goes away when warm.
2007-01-12 04:08:28 · answer #1 · answered by JDM_BA4 3 · 0⤊ 0⤋
Honda Prelude 95
2016-11-13 21:37:15 · answer #2 · answered by Anonymous · 0⤊ 0⤋
I believe this is normal during cold weather starts. I have wondered this myself and haven't yet found an answer.
My guess would be; 1) when it is cold out, the engine oil is thicker and it's fluidity is not as fast as when the oil is warm.
2) Engine idle is controlled by various sensors.
Coclusion: When the sensors detect that the engine is cold, perhaps through the IAT sensor, it send a command to the PCM to idle high for approximately 30 seconds to 1 minute in order to circulate engine oil to vital engine parts faster so as to minimize bare metal to metal contact. (Since the oil settles at thhe bottom of the oil pan and thickens up during cold weather.)
2007-01-11 16:26:48 · answer #3 · answered by Changed 3 · 0⤊ 1⤋
Idling high when you first start your car when it's cold is normal, especially that your car is more than 10 years old. I have a car that's more than 10 years old and when I start it up, it idles at 1,500 or higher. It is normal for older cars, they need the engine oil to be heated so it will circulate smoother, that's why your RPM is high when you first start it.
2007-01-11 16:20:01 · answer #4 · answered by mrhuangsta 3 · 1⤊ 1⤋
Iam assuming you mean when in the morning you start the car up it tends to have an arratic idle, like reving up and down when the motor is cold........it could be the TPS or air bypass valve is going out.
2007-01-11 16:29:23 · answer #5 · answered by vankstwer 3 · 0⤊ 0⤋
Check the Idle position sensor it may be going bad. Good Luck!
2007-01-11 16:15:49 · answer #6 · answered by LSD 4 · 0⤊ 0⤋