GenVibe - Community for Pontiac Vibe Enthusiasts

Was driving the other day and at some point when I let off the accelerator the engine continued to run at about 5K+. Got it home, turned it off and left it. Been sitting a few days and I just turned the key and it reved up just like as if I floored the gas pedal. Opened the hood just now to look to see what might be the problem and I notice these lines flopping around and wonder if that has something to do with it. The first pic shows a connection but nothing is attached. That may have been that way a while for all I know. The second show a hose with a broken connection but I can't find where that may have been attached to. Now I thought it may have been the spring at the connection of the throttle cable but that has tension and looks fine. Any ideas appreciated.

I snapped a pic of mine, and it looks like the end in your left hand goes to something under the intake ducting. There is another tube that goes from under the intake duct back to the open port on the solenoid.



I can remove the intake ducting and take a pic of the vacuum routing if you want.

Are you missing the diagram of your vacuum routing that's underneath your hood? Should be there and tell you exactly what goes where.

That vacuum switching valve with the exposed nipple, heheh, is for the airbox flapper. I can't recall the diagram/routing offhand, though. And, it's 115am, sooo....

ImUrOBGYN wrote:Are you missing the diagram of your vacuum routing that's underneath your hood? Should be there and tell you exactly what goes where.

That vacuum switching valve with the exposed nipple, heheh, is for the airbox flapper. I can't recall the diagram/routing offhand, though. And, it's 115am, sooo....

Ok. So I found the hose that attaches to the exposed "nipple". It was just lying disconnected. Probably knocked out by the NTB tech looking for stuff he could charge me for last month. The "mystery" hose with the broken nipple I see connects to the back of the airbox lid. Apparently the previous owner had applied a fix that failed.

Thanks for pointing out the hose diagram that was on the hood of the VIbe. I'd never even noticed that until you mentioned it!

When I get this back together I'll be surprised if this solves the idle issue. I'll look at the idle air control next, I guess. I will say that this occurred right after I attempted to see if "lift" was still working. So I had the engine running between 6-7k rpm. If that is any clue.

Regards

Well, any unmetered air taken in by the engine will call a surge and/or uneven idle. Not to mention, will have you running a bit lean. Get it back together, drive it a bit and let us know if there are any new symptoms or if the same ones remain. It sure can't hurt it to have vacuum lines where they go!

PS - When I bought my Vibe, the vacuum lines were ran incorrectly. No check engine light or anything. Thank goodness for vacuum line routing diagrams! I never see other GTs or XRSs to compare to.

ImUrOBGYN wrote:Well, any unmetered air taken in by the engine will call a surge and/or uneven idle. Not to mention, will have you running a bit lean. Get it back together, drive it a bit and let us know if there are any new symptoms or if the same ones remain. It sure can't hurt it to have vacuum lines where they go!

PS - When I bought my Vibe, the vacuum lines were ran incorrectly. No check engine light or anything. Thank goodness for vacuum line routing diagrams! I never see other GTs or XRSs to compare to.

All back together and still idles at 3K+ when I start the car. If I disconnect the plug to the device just under where the throttle cable attaches then it drops to about 2.5K.

IACV issue?

thebarber wrote:IACV issue?

Thanks

That is what I was going to look at next. Is the IACV the device I unplugged that is directly beneath where the throttle cable attaches? Know of a way to test it rather than just replace?

SirLinux wrote:

thebarber wrote:IACV issue?

Thanks

That is what I was going to look at next. Is the IACV the device I unplugged that is directly beneath where the throttle cable attaches? Know of a way to test it rather than just replace?

Today I took apart the IACV. I found It was binding inside so didn't rotate freely. Once I cleaned it up with carb cleaner it was much improved and I thought for sure that was going to be the fix. Unfortunately when I got it all back together the problem remained. I am about to throw in the towel and take it in to a dealer for them to figure it out. I guess it could still be something with the IACV like the solenoid. Anyone know how to test that? I hate to buy another just to find it isn't the issue. The RPMs do drop when I unplug it by about 500 rpm or so. Not sure if that means it is working or working incorrectly.

I thought I'd previously mentioned this but can't find where I did, so...

Now, this is coming from my Supra xp, not Vibe xp, so this may or may not apply. That being said, have you checked your TPS, Throttle Position Sensor? On my Supra, this can go bad or it can still be good, but not be in the proper position. The TPS on the Supra once attached, must be rotated to the right position/voltage and then plugged in (you can have it plugged in while you adjust it, as well.) Of course, that's a big old school and it's probably done differently on our cars. Still, should be something controlling the tps. I'd look thru the Vibe manual or at my actual Vibe but I'm not able to currently.

http://www.monkeywrenchracing.com/produ ... ts_id=2253

It's probably your IACV. This is a pretty common issue on the 2ZZs.

Just an update on my high idle issue. Replaced everything I could think of to avoid the dealer. Throttle position sensor, IACV, throttle body to manifold gasket, upper and lower intake manifold gaskets. Nothing changed the high initial idle symptom. So last night I decided to drop it off at the GMC dealer to look at. Noticed once it warmed up the idle would drop to about 1k then rev back to 2.5k or so repeatedly. It would not maintain a constant idle speed.

Dealer service called and told me that the problem was something called the powertrain control module wasn't giving out any data so that needed replacing. Pricey part to replace at about $850. Ouch. Merry Christmas.

So the saga continues. I go to the dealer to pick up the Vibe after they have replaced the power train control module. Almost immediately when I start the car the idle still appears high - about 2K or so but I figure maybe because it is cold. I continue to drive it home and the idle will just hang about the rpm of the speed I am driving when I take it out of gear. This is different acting than previous to them changing the control module where immediately the idle was over 3K when starting the car. So I am kind of ticked off at this point having dropped $900 and things are still not right. Did they even drive it after replacing the module? I think not. I take it back to them and they see the idle is way up still. I get all kinds of apologies and a loaner car.
Got a call yesterday and was told that the problem now is the butterfly in the throttle body is not closing all the way and maybe sticking when driving. A replacement is about $1900.
When I had that off working on it myself I did notice that the butterfly did not close completely so that there was a slight gap. I did not know if that was normal or not. I figured there had to be some gap to let a little air in initially but perhaps that is the job of the IACV. There didn't seem to be any sticking or hanging up of the butterfly manually operating the throttle the times I had if off. I am certainly not going to give them the money they are asking to replace the throttle body as I can get one on my own for much less. Question I have is does anyone know for certain if that butterfly is supposed to close off completely that opening in the throttle body? I of course don't have another one handy to compare. I am having trouble believing that I have 2 completely different problems creating idle issues at the same time.

It should close completely. It is the Idle Air Control Valve that handles the air to maintain idle.

http://www.2carpros.com/articles/how-a- ... body-works

I am sure you can find a good used one.

vibrologist wrote:It should close completely. It is the Idle Air Control Valve that handles the air to maintain idle.

http://www.2carpros.com/articles/how-a- ... body-works

I am sure you can find a good used one.

Interesting. I googled that question and got this -
http://www.passatworld.com/forums/b5-ga ... etely.html

Other posts seem to indicate that a slight gap is normal.

Similar to what I see on my Vibes' throttle body butterfly. There is a small gap when closed. I am thinking this dealership doesn't have a clue. The fact that they didn't drive it at all to test it after replacing the control module indicates that. I am out $900 so far with no resolution. Exactly why I was hoping to avoid a dealership in the first place.
If I can't figure it out after another go at it myself I guess I'll take it over to a Toyota place and let them try.

I cleaned the throttle body on my '05 base Vibe and did not notice a gap.

The VW posts that you referenced may be based on a different way of regulating the idle using the Drive By Wire throttle actuator. I had the impression your throttle body has a cable and an IAC valve.

I would hope a GT owner can clear this information up for you.

Just curious what is the end story for this. I am having the same problem with my 2zz (06 GT with a throttle cable). I replaced the TPS (which is the code that came and went) to no avail. I brought it to GM, and they were not much help, they wouldn't even tell me if they checked the vacuum lines or the electrical connections. They told me they would clean the throttle body for $600 and then if I wanted replace the IAC for another $600. Paid $130 for the diagnosis.

I'm planning on pulling the throttle body this weekend for a thorough cleaning and try to clean out the IAC as well. I've never done that before, so I'll have to look up how that goes.

I don't know the outcome of this original issue.
Cleaning the TB is the way to go and those estimates...tsk. I'll clean your TB for half the price and it would still be a rip-off!

Make sure you to use a product specifically formulated for TB's. I like CRC aerosol cans. Most TBs have a coating that could be dissolved by the wrong chemical. Spray the TB inside and out. The most critical area is where the butterfly touches the bore.

While you are there you may clean the MAF sensor too. Again use a dedicated MAF sensor aerosol. Do not touch the filaments with anything but the spray of the aerosol.

My observations on 2 different TBs is that the Butterfly is shifting and jamming on the TB. IACV cleaning/replacement did nothing. Cleaning the TB seem to make it worse. Cleaning the MAF is useless. Replaced every vac line going in and out of the TB. Had a TB rebuilt by MWR still no help.

There's a magic bullet somewhere and there's several guys trying to figure it out.

Goodluck

Salsa: I'm a bit confused by your message. In sentence one, you seem to be indicating that the butterfly valve is intermittently sticking on the throttle body. Since you replaced it twice(?) and still got no results, are you saying that there is an inherent defect in the OEM throttle bodies on the Vibe/Matrix? I, like many others here, are struggling to fix this problem. My mechanic has done all he can and believes the only thing left to do is replace the throttle body. He only will do that if/when my car actually begins to stall at stop signs. While it does rumble pretty good from time to time, most of the time it runs fine, with one exception: I also seem to get days where the idle is a bit too high (900-950 RPM). The car is fully warmed up for over an hour, yet when sitting and crawling in stop/go traffic, my idle will not go down to the proper 750 RPM like it normally does. So I'd venture a guess that 80% of the time everything works hunky-dory. 10% of the time the idle dives too low (600-650 RPM) at stop signs causing an engine rumble, and 10% of the time I have an idle that is slightly too high.

With millions of these Corollas/Matrixes/Vibes sold, somebody out there has to know what's up with this idle issue. It ain't just carbon in the throttle body or on the glass mass air flow sensor. In my case, it isn't the PCV or a bad intake manifold gasket.
In general, how hard is it for my mechanic to look for a vacuum leak?

In general, how hard is it for my mechanic to look for a vacuum leak?

It should not be hard but maybe time consuming chasing a vacuum leak. There are several methods. One of them is using a smoke machine that induces smoke into the intake, and if the smoke exits somewhere there is a vacuum leak.
Another method is using an enrichment tool. The engine idles and a flammable gas or liquid is directed at suspected leaks. If the idle reacts to the added fuel a vacuum leak is detected.

You are aware of the usually suspected vacuum leaks with this car. Maybe you have one that is less common. I.e. the gasket under the oil filler lid, an EVAP line, or the brake booster line.

This might be a dumb question, but how bad is it to drive the car with high idle? Mine normally starts off at 2K, then calms down after warming up to about 1200 RPM.

I cleaned the battery grounds and the throttle body, and replaced the TPS (because that is the code that got sent). With 207K on my car and the clutch starting to go, and the steering fluid being dark (rubbing gears???) I am going to replace the car. I found another vibe that I am going to buy, but I need to wait a week to get it.

In the meantime, should I still drive my car? Or limit the driving with this issue?

Thanks

of course keep on driving it. The car is supposed to rev at 2000 RPMs when it is first started. Then it slowly backs down as the engine warms. On a Vibe with automatic transmissions, the tachometer should read 750 when the car has been operating for 15 minutes or more at a reasonable air temperature (70 degrees). I'm not sure what a manual transmission bottoms out at when fully warm but I'm guessing there are two readings: one with the clutch pedal depressed and sitting at a stop sign, and one in neutral with the clutch disengaged. Thrilled to hear you are buying another Vibe. Good luck with the purchase.