Hi,

I realised latelly that my car have two idle speeds, one when it's cold (~700rpm), and (sometimes) one when it's hot (~800rpm). Also, when idling, the motor is a little irregular.

I tested and cleaned my IAC valve latelly. I would be surprised if it was the problem. I also cleaned my intake. No code have come out of the ECU. Anyone would know what it could be?

Thanks a lot

 

No idea what your problem could be but all engines have seperate idle speeds. When you first start the car and the engine is cold it will idle high, to warm the engine. Once you drive and warm up the engine, your idle will drop. Though with this being said, your's is opposite and sounds really fucked up.

 

It's hard to explain, but let's say that the idle of my car have this curve:

RMP
------..x
------.....x
------.........x
------...............x
------.........................x
800--........................................x......... .................xxxxxxxxxx
700--.................................................. ....xxxxxxxx
------| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
------very cold---------------------------------"cold"----hot
------------------------------------------------------temperature

That's more like it. It's raising to 800rpm after falling to 700rpm.

Thanks for answering even though I wasn't clear.

 

I would try adjusting your idle.

Also check your pvc valve to see if its clogged (this has been known to cause somewhat of a rough idle). Check your timing as well.

But when you say the motor is a little "irregular" what do you mean?

 

what kind of car is this?

 

my 00 V6 accord is doing that right now, its a little less with the AC on,
but its almost like the engine is about to die, then catches itself, everything dims when it dips too.
and if its humid it does it more, lately my lights are starting to flicker occasionally too.
i dont know what it is, im gonn ahcnage the PCV valve soon but other than that i dont knwo what else it could be, but i dont think its the PCV valve tho.

 

My car is a 1994 Accord, with an F22B2 engine.

I would be surprise that an idle adjustment would change anything, because when it's lowered, the 2 idle speeds remains, but at a slower rate.

I also changed my PCV valve last year. I'll test it anyway, who knows. Checking the timing is a good idea. Last year it was ok, but maybe a tiny out of time. If the timing got worse lately, it could explain my problems, or part of it.

By "irregular", I mean that I'm expecting a steady, low vibrating sound&feel, but it sounds like there is some slow periodical misses aroud every 2 secs, the motor slows down a bit & get a little more shaky, then catch up. I would suspect some oil leak (head gasket?), but the spark plugs and the muffler deposits indicates more a problem with the air/fuel mixture. I was told that this was ajusted by some sensors, so I cleaned my intake, but it didn't change anything.

snikwad: I'm not a pro, I only can recommend checking the spaks plugs and wires, clean the intake with some Intake Medic, and try other little low cost things before anything else, if it isn't done already.

Thanks to all.

 

i think its just temp variation