help asap! very strange idle only when in gear?

[tdi-tom]

Hey guys I've searched google and the forum and haven't found any way to fix my problem so I've made an account to hopefully get some help! So the car is a 92 1.8 v6 gs 5 speed mx3, it starts up awesome and runs awesome up until you push the clutch in and put it in gear and then the idle bounces between 500 to around 1200 orso until I put it back in neutral. The clutch doesn't cause the problem because I can have the clutch in or out and it doesn't affect the idle, only when I put the car fully Into gear, any gear whether its 1st 2nd 3rd or whatever but then idles fine shortly after taking it out of gear so stop lights suck unless I quickly whip it Into gear right when the light goes green but the Idle Instantly drops when it goes into gear so Its a bit tricky. any help or suggestions ?!?!? Thanks in advance!
-Tom

[Ryan]

This is normal. Edit, well, its normal that the idle changes, the bounce isn't.

What is your idle normally at? Operating temp, out of gear.

[tdi-tom]

I'm not posative but around 12-1500 rpm'ish? The normal idle seems about right but no matter what when its in gear it just falls from around 12 down to 500 then comes back up to 12 orso then falls etc etc its always the same never fluctuating any further than that and never dies. Always runs mid temps, I was almost suspicious the temp gauge doesn't work but It never once overheated on me so it must be alright. And yes manual trans.

[mikeinaus]

your idle is set between 12-15k? thats way too high, it should be around 650rpm. having your idle set too high will cause it to bounce when its in gear.

its normal for the idle to raise a few hundred rpm when its put in gear (92/93 mx3's that is). if its set too high to begin with the computer thinks there is a vacuum leak causing the high idle and tries to correct it. im not 100% sure thats the reason it bounces but i had the exact same problem when mine was set around 1200rpm. try lowering it and let us know if it helps.

[tdi-tom]

I'm not posative thats where the idles at ill haveta go fire her up and check again as the cars been parked for almost a week since its my girlfriends car were trying to get going for her for when she gets her lisence finally. I was actually told just awhile ago to try turning the idle up since it stops idling wierd once the cars moving or any throttle Is applied. but ill give both a shot and Thanks a lot for your time again guys I really appreciate It.

[tdi-tom]

Okay so just fired It up, idled around 2k for awhile and then slowly came down to about 1100-1200 range, doesn't do the idle thing when its cold only when its watmed up and once put Into gear It climbs to 1500 then drops to about 900 then back up to 15 and back down to 9 etc etc until taken out of gear. Any more Info now that I have more accurate readings?

[mitmaks]

You probably need to adjust your TPS and adjust your idle in diagnostic mode only.

[Pritchett]

Your not listening. Your idle is at 1100-1200rpms, you were informed that the normal idle is at 600-700 and if above to lower it. What you need to do is use a paper clip or similar small metal wire and jump the "TEN and GND" in your dianostics box that's located on the firewall on the drivers side. Wait till your engine is warmed up first, then jump, then turn the big Phillips screw in the top of your throttle body. Clockwise is to lower your idle, counter clockwise will increase. Turn it in till your needle reads 650-700, pull the paperclip and see if it still bounces once it's in gear.

[tdi-tom]

Sorry, I did understand a bit but didn't know how to adjust the throttle I just went out trying to adjust the cable and it did nothing really but you all probably could have told me that haha, alright I'll try that method and see what happens 6-700 just seemed low to me but you guys are the knowledgeable ones! and thanks again!

[mitmaks]

http://www.mx-3.com/manuals/showimg.php ... F2-104.gif

[_lithium_]

Okay, not gonna lie I was lazy and didn't read a lot of the posts, but from the sounds of it your experiencing the same thing I did a few months back. I was stuck buying a new TPS, cleaning almost everything in the engine I could, and ended up finding out that the vacuum hoses that lay under the Intake manifold were really messed up. I would take a flash light and shine it (from the left side of the intake mani) and see if you see any of the things broken (forgot the name but its a small round plastic ball and has a hose on each end.

[tdi-tom]

Well guys I finally got the car on the road so I could park my vw for the winter, been driving it for a few weeks now with the idle turned down to 5-600ish and wow suprise suprise it actually worked! And to think it was that simple... the previous owner had the car into two different mechanics a couple times and couldnt figure out why it was doing the idle thing so he listed the car at 1000$ as is but I widdled him down to 500 cash since he was so stumped on it and now she runs like a top! Well minus a slight hesitation or casual jerkyness sometimes upon clutch release in first and second and I wish I could somehow get it to run a bit cooler... there's been about three separate times where I've almost had an mx3 but the deals have fell through but since now owning one Im sure kicken myself in the arse for not getting into one sooner!

[mikeinaus]

glad that fixed your problems. welcome to your addiction