rolling engine idle after disengaging clutch during moderate engine load

[soccerballtux]

http://youtu.be/f52jsCP8BPI

I've read about this somewhere before.
I will do more research and post back with my analysis.
Right now just...dumping this here for thoughts I guess, if anyone knows exactly what it is. My friend says its because I haven't reset my trip meter () I will reset it soon

camry engine.

 

[tortillasoup]

we have no idea what vehicle this is. I know on Hondas, you can get a bouncing idle due to a large vacuum leak, a bad/clogged/frozen idle air control valve or on older hondas, a bad FITV. Newer cars that don't have an idle control valve would probably have an issue with the throttle body or again a vacuum leak somewhere.

 

[Wuzup101]

What kind of car? Any work performed recently? Vac leak / throttle body issue could be likely. Could be loss of power on one cylinder. Could be obstructed exhaust (those damn mice nest everywhere lol) but nor really likely unless it has been sitting. Does it happen only when the engine is warm or will it idle like that on startup? Does the ac being on vs off have any effect on it? Huge mega cam lol?

I'd probably start off by looking for a vac leak.

 

[master_shake_]

is it a nissan?

try calibrating the throttle.

looks like a nissan cluster sorta.

 

[soccerballtux]

oops, camry sorry.

far as I can tell it's not a vacuum leak from the WD40 test, and also my STFT numbers are consistently under 1%; and I recently cleaned the throttle body. This car doesn't have an IAC.

 

[soccerballtux]

What kind of car? Any work performed recently? Vac leak / throttle body issue could be likely. Could be loss of power on one cylinder. Could be obstructed exhaust (those damn mice nest everywhere lol) but nor really likely unless it has been sitting. Does it happen only when the engine is warm or will it idle like that on startup? Does the ac being on vs off have any effect on it? Huge mega cam lol?

I'd probably start off by looking for a vac leak.

this seems to be more noticable on startup but that might just be because of the drive out of the area. This video was taken after engine was warm. Again this happens only when the engine is loaded and you rapidly remove power.

 

[inachu]

Also called idle surge.

Search on youtube and a guy fixed his by cleaning out the gunk on the inside of the rubber hose.

 

[soccerballtux]

Also called idle surge.

Search on youtube and a guy fixed his by cleaning out the gunk on the inside of the rubber hose.

don't have any of that to clean

 

[lsd]

What year Camry?
Did you do a throttle body reset after cleaning? I'm not familiar with Toyota's but on some cars if you clean the TB you will need to do a relearn procedure.

 

[Squeetard]

I recently cleaned the throttle body.

There's your culprit. Prolly gunked up your map or maf sensor. Or your throttle position sensor.

 

[leper84]

How far under 1% are the fuel trims? Up to -8 or so is fine, more than that and you're probably looking at a vacuum or intake leak. How were you using the wd40 to test for leaks? Easiest way I've found is spray around every sensor, seal, hose or piece of rubber with throttle cleaner and then watch for the fuel trims to go more negative.

I'd also +1 what lsd said, If your throttle body is drive by wire then you need to start with doing a relearn for the throttle position; the more dirty the tb was, the more you need to do it.

 

[soccerballtux]

There's your culprit. Prolly gunked up your map or maf sensor. Or your throttle position sensor.

was doing this before and MAF was squeaky clean to begin with. unfortunately.

 

[soccerballtux]

How far under 1% are the fuel trims? Up to -8 or so is fine, more than that and you're probably looking at a vacuum or intake leak. How were you using the wd40 to test for leaks? Easiest way I've found is spray around every sensor, seal, hose or piece of rubber with throttle cleaner and then watch for the fuel trims to go more negative.

I'd also +1 what lsd said, If your throttle body is drive by wire then you need to start with doing a relearn for the throttle position; the more dirty the tb was, the more you need to do it.

as in, within 0 to 1%. :/

on my 06 scion tC 08 engine, thankfully there's a limited number of connections and they're all near each other. I sprayed around all of them,,,, but wasn't watching the trim just listening for the idle.

throttle body is electronic.

I guess I'll get around to seeing if I can find what I read originally.

additionally, on start the car doesn't get fuel for more than a split second and dies so I just hold the key in the start position for about 3 seconds in stead of 1. It's almost like transponder isn't transponding to permit fuel to go into the cylinder, except that it is, if only for a quarter second and then cutting out. and everyone tells me fuel pumps don't fizz out.

I don't think these issues are related as the rolling idle has been this way for years and I don't think it's likely a problem. The other thing and a rough idle/die sometimes randomly are new since the AC was recharged.

 

[tortillasoup]

There's your culprit. Prolly gunked up your map or maf sensor. Or your throttle position sensor.

A TPS sensor would unlikely to get gunked up, a MAP sensor, maybe, and a MAF sensor is usually located prior to the throttle body so that's unlikely.


If OP's idle was fine prior to cleaning the throttle body, two things could have happened: 1. If the car has an idle control valve, he gunked it up and it's not working properly anymore. He needs to get back in there and clean it properly... 2. If it's anything like the '99 V6 Toyota Tacoma, when you clean the throttle body, you can create a vacuum leak because the gunk that was in the throttle body was what kept the butterfly valve sealed and now it's no longer sealed.

Op also could have damaged a hose, or a rubber hose attaching to the throttle body or something isn't sealing properly anymore because it's old and brittle.