Strange: VGIS Not Working!

BosnianLanos · Post by **BosnianLanos** » Fri Apr 28, 2006 12:15 am

I always thought that my new Lanos was a little weak off the line unless I revved it high. I thought this was just the car being lazy and that it would wear off after some new plugs and fuel injector cleaner. After that did nothing, I was a little worried because I thought that maybe my clutch was already slipping because I had driven it wrong or something, but I did the handbrake stall test and passed. I checked all the sensors to make sure that my O2 and MAP and AIT were all functioning. Everything was fine. So this morning I had a little lightbulb go off in my head that told me to check the VGIS. Guess was right. My VGIS system if faulty.

All throughout the RPM band, the little VGIS actuator stays in the "engaged" position (it is getting vacuum all the time), so the car is always using the same length of runners. Meaning I have very little power up to 3,000 RPM, and at about 5,000 RPM, I don't get that same kick of power that I get in my green Lanos.

I would assume this is faulty because under the same conditions in my green Lanos, when you rev the engine in idle, the vacuum causes the VGIS to go from off to on and when the RPM drop to off again.

The main issue that I found is that the vacuum hose that runs from the VGIS canister to the little brass actuator on the intake manifold is always under vacuum, so the VGIS is always stuck in the same position.

Can someone provide me with a reason that this is happening or at least a diagram or pic of the correct location of the vacuum hoses?

Please help!

MMamdouh · Post by **MMamdouh** » Fri Apr 28, 2006 12:26 am

if i understand correctly then the problem you are facing is that you are stuck with the short runners due to the fact that you got vacuum actuating the VGIS system all the time... right?

in this case i suspect that the solinoid is stuck open and thus leaking all the vacuum to the VGIS actuator... to make sure that this is the problem try to use the solinoid of the EGR valve to replace the VGIS solinoid or even try a solinoid form the green woo if you still got it.

try this and give us your feedback... the solinoid should be on the other side of the vacuum line going to the VGIS actuator and as i recall it is mounted on the firewall near the vacuum canister.

MMamdouh

MMamdouh · Post by **MMamdouh** » Fri Apr 28, 2006 12:31 am

just went through a 1.6 DOHC engine bay pic and the solinoid is right next to the vacuum canister indeed.

MMamdouh

BosnianLanos · Post by **BosnianLanos** » Fri Apr 28, 2006 1:03 am

Yeah, I just checked all the fuses and wiring and everything seemed to be set up OK. I guess the last possible thing is the solenoid which I guess is either damaged, or for some reason getting a constant signal to stay open.

The thing that I find strange is that the car isn't throwing a CEL, which it should do in the event of a solenoid failure.

I guess I have to try to get a solenoid.

GsiTurbo · Post by **GsiTurbo** » Fri Apr 28, 2006 2:08 am

Also make sure its not the foreign object/oil/gunk build-up inside of your intake manifold, that would prevent the VGIS plates from turning. Try to turn them by hand first.

BosnianLanos · Post by **BosnianLanos** » Fri Apr 28, 2006 2:22 am

GsiTurbo wrote:Also make sure its not the foreign object/oil/gunk build-up inside of your intake manifold, that would prevent the VGIS plates from turning. Try to turn them by hand first.

They rotate with no problem. When I pull of the vacuum hose, they immediately disengage like they should. I'm almost convinced its the solenoid now.

This is the first I'v ever heard of a faulty VGIS.

MMamdouh · Post by **MMamdouh** » Fri Apr 28, 2006 12:32 pm

i don't think a faulty solinoid would throw in a CEL... only the consequences of a faulty solinoid would do that as in an alwys open EGR which causes miss fire and stuff like that.

is the solinoid stuck open or does it have signal all the time and that forces it to open??

keep us posted.

MMamdouh

daewooluvr · Post by **daewooluvr** » Fri Apr 28, 2006 1:45 pm

could also be a mixed up vaccuum line. check to make sure they all go where they should.

Nubi N00b · Post by **Nubi N00b** » Fri Apr 28, 2006 4:36 pm

daewooluvr wrote:could also be a mixed up vaccuum line. check to make sure they all go where they should.

I own a Nubira, so this is a stab in the dark, but I recall reading through some past threads where people had suggested removing a vaccum line from the control unit. The general consensus was that it would close the VGIS system and you won't have terrible torque figures. Perhaps you have lost of of the connections to the control unit?

BosnianLanos · Post by **BosnianLanos** » Sun Apr 30, 2006 4:45 pm

Well, I did some testing these past few days and have found the problem, but not the solution.

I tested the VGIS fuse, and it was fine.

I triple checked the vacuum hoses, fine.

Removed the solenoid, checked resistance and tested with 12V source, fine.

It turned out that the fault is that the actual wire going to the solenoid. Regardless of engine temp and RPM, it is always giving power, meaning the solenoid is permanently engaged meaning the VGIS is permanently engaged. I reset the ECU and did the engine re-learn procedure but the problem remains the same.

I'm thinking it may be a fault with the ECU. Luckily, still have 1000 miles on the actual dealer warranty so I'll take it in and see what they can find.

If you guys have any other ideas, keep 'em coming.

JohnnyC · Post by **JohnnyC** » Sun Apr 30, 2006 5:37 pm

VGIS isn't on the list of acronyms.. What does it stand for?

Nubi N00b · Post by **Nubi N00b** » Sun Apr 30, 2006 6:06 pm

VGIS = Variable Geometry Intake System

If I gather correctly, the system is controlled based on the RPM window set forth by the engine. If your scenario, BosnianLanos, is correct in that the signal wire is always transmitting the "ON" signal, it stands to reason that your ECU/ECM is either acting up, or receiving false information from the other sensors (presumably crank position or cam position). I noticed in reading some of your posts that you have two of the Lanos models. Perhaps you could take a moment and swap ECU/ECM's and see if at idle the VGIS system opens appropriately. I realize that one of your cars is an automatic transmission and the other is a straight drive; however, I do believe that for the idle test I am mentioning that the ECU/ECM differentiation between transmission types can be over-looked. This will at-least inform you if you have a faulty ECU/ECM or if your sensors are transmitting incorrect data.

Dave

GsiTurbo · Post by **GsiTurbo** » Sun Apr 30, 2006 6:08 pm

JohnnyC wrote:VGIS isn't on the list of acronyms.. What does it stand for?

Variable
Geometry
Intake
System

I think.....

Daniel · Post by **Daniel** » Sun Apr 30, 2006 8:43 pm

BosnianLanos wrote:Well, I did some testing these past few days and have found the problem, but not the solution.

I tested the VGIS fuse, and it was fine.

I triple checked the vacuum hoses, fine.

Removed the solenoid, checked resistance and tested with 12V source, fine.

It turned out that the fault is that the actual wire going to the solenoid. Regardless of engine temp and RPM, it is always giving power, meaning the solenoid is permanently engaged meaning the VGIS is permanently engaged. I reset the ECU and did the engine re-learn procedure but the problem remains the same.

I'm thinking it may be a fault with the ECU. Luckily, still have 1000 miles on the actual dealer warranty so I'll take it in and see what they can find.

If you guys have any other ideas, keep 'em coming.

Hi,

In Run & Start the VGIS solenoid has always one wire at +12volt trough the fuse. The other wire is or open or grounded trough ECU acting like a switch. You may have this wire pinched to ground somewhere or you ECU is bad.
Anyway if the car is still under warranty I would like to let the dealer make his job.

Daniel

MMamdouh · Post by **MMamdouh** » Mon May 01, 2006 8:57 pm

i think it is a wiring issuer as well... if it is the ECU acting up then it would be a bigger problem as you know the ECU sends a signal to the VGIS solinoid based on other data from the engine - ithing it is the current RPM or so - and if something is wrong it would trigger a CEL i guess.

anyways if you can, check the wiring and make sure nothing is screwed up or grounded somewere or else leave the job to the dealer as long as the car is still under warranty.

MMamdouh