# 8v idle issue



## 2OVT (Sep 11, 2009)

Yup...another problem with the new Golf. Previously when you would fire the car up it would shoot up to about 1200 and then bog down and start to die unless you gave it some gas and eventually it would start to idle at about 900-1100. Well...that problem is still occurring except now it doesn't want to idle at 900-1100...but 2100. It now smells as if its burning lots of oil or maybe its the smell of fried rings? Either way I think this things about to go =/ kinda pissed my brother picked it up now and is starting to have issues. What does it sounds like to you guys? Here is a short vid of it starting up and idling after being warm. 

btw; it was me giving it the little rev from 2-3 grand to see if it would come back down but nothing...


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## ziddey (Apr 16, 2006)

what is that? golf gl gx motor cis-l? 

vacuum leak?


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## 2OVT (Sep 11, 2009)

ziddey said:


> what is that? golf gl gx motor cis-l?
> 
> vacuum leak?


 golf gl i believe. CIS. 
I have not yet checked for vacuum leaks. I was assuming it was more the timing, maybe bad idle air control valve or something.


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## ziddey (Apr 16, 2006)

It smells of burning oil? From the engine or the exhaust? Valve cover gasket is common to go bad on these cars. 

Cis-l only uses idle boost valves (1 for normal conditions, 1 for ac), and an aux air valve (bimetallic strip with heating element to allow more air while cold). There is no "fancy" ISV like with cis-e/m/digi. 

Sure, it could be that your AAV is maybe gunked open, but that wouldn't cause your dropping idle. Having to hold the throttle to keep the engine running is indicative of a vacuum leak / bad mixture (you're forcing more air--more of which will be metered). 

I haven't fiddled much with cis-l, so I don't know how the WUR works, but that's something you should look into as well since it controls cold enrichment. 

As for timing, unless you've tampered with it or the distributor isn't locked tightly, it shouldn't wander.


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## 2OVT (Sep 11, 2009)

Would this contribute to a vacuum leak, the line that runs from the top of the valve cover to the (what i thought was the mas air flow sensor) is gone. There is just a dinky little breather filter? And the fact that it is pretty much just sitting there...you can pull up and it'll come right out. How exactly should I look for a vacuum leak? I've never done this before  










other than that, I'm looking around for obvious signs.


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## ziddey (Apr 16, 2006)

use your ear. use starter fluid. flex and visually inspect all vacuum lines. 

the stock arrangement would have a small hose running from the breather valve to the intake manifold. The nipple would thus then need to be capped if using an open vent system. 

The big hose that runs to the airbox poses no problem since it's pre-meter. 

If you're using a filter for your breather, that could explain the oil smell. Confirm. 

Personally, I've tried some of those filters and they just don't seem to be free enough to flow well. Not sure if the increased blowby at load will be able to go past the filter well enough or not, but I decided it wasn't worth risking increased crankcase pressures.


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## 2OVT (Sep 11, 2009)

ziddey said:


> use your ear. use starter fluid. flex and visually inspect all vacuum lines.
> 
> the stock arrangement would have a small hose running from the breather valve to the intake manifold. The nipple would thus then need to be capped if using an open vent system.
> 
> ...


Sounds good. I'll have to get some starter fluid then. I'll let you know how it is. The line you are talking about that runs from the breather to the intake, isn't that in the picture?


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## ziddey (Apr 16, 2006)

yeah I didn't see the picture earlier for some reason. I didn't realize it was still hooked up. I'm not really sure of that whole design as it is. I've always just gotten an elbow and ran my line straight to the airbox. 

Then again, in 2 mk2's I've worked on, that small vacuum nipple was clogged up from all the blowby anyway.


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## 2OVT (Sep 11, 2009)

ziddey said:


> yeah I didn't see the picture earlier for some reason. I didn't realize it was still hooked up. I'm not really sure of that whole design as it is. I've always just gotten an elbow and ran my line straight to the airbox.
> 
> Then again, in 2 mk2's I've worked on, that small vacuum nipple was clogged up from all the blowby anyway.


 Ok. Is there n e thing else that would cause this problem or are you certain it's a vacuum leak? Is there n e thing else I can use besides starter fluid to help check for a leak?


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## ziddey (Apr 16, 2006)

2100rpm when it's warmed up is extremely high. There's 3 devices that are capable of boosting idle for your car. You can inspect them to see if they're stuck open. You'll find 2 idle boost valves next to eachother with electrical plugs going to them. One is triggered by AC, the other when the idle dips below a threshold. So far I've only seen these fail to trigger when needed, but I suppose it's possible for them to be stuck open. I'm not sure if you'd be able to see whether it's open or shut, but you can try blowing through to see if it's open or not. 

Then there's the auxiliary air valve, which is mounted under the intake manifold. This one you can remove and visually inspect the size of the opening. It isn't unusual for these to get gunked up over time, but usually it results in them being stuck too closed. You can remove it and clean it out with something (not sure if brake cleaner would be acceptable, but it's what I used, followed up with some pb blaster to lube it). Once it's all cleaned up, you can apply 12v to it and observe the action as it closes. Once it's warmed up, it should be fully closed or close to it. 

But again, I don't know if these devices combined can cause that high of an idle. Perhaps if all 3 of them failed open, which is extremely unlikely. So again, we're most likely looking at vacuum leaks. While the car is cold, the oxygen sensor isn't online, so the ecu can't enrichen to bring it back to stoich, which explains your problems while cold. Then once warm, the ecu can add additional fuel, which when combined with the excess air, results in a high idle. 


Has the car always done this, or is this a new problem?


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## 2OVT (Sep 11, 2009)

My brother just bought the car a few days ago. We figured that it wasn't a huge problem and he got it for a steal. Im guessing you're right and it's a vacuum leak. I believe the o2 sensor is out. The Oxs light is on. I'm guessing that's also adding the oil-ish smell as well.


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## ziddey (Apr 16, 2006)

Well you picked a good platform to work on. These cars are easy maintenance and cheap on parts. 

The OXS light is triggered by a mileage counter. There's no sophisticated o2 sensor monitoring system involved. If look at the raintray area, you'll see the speedo cable hooks up to a box, and then another stretch of cable that runs to the car. You can either unplug the wiring for the box and bypass the oxs light entirely (again, just a mileage counter), or there should be a button on there to reset it. 

As for the oil smell, again, is it coming from the engine or the tailpipe? If you've got blue exhaust, that's a more serious problem. If you're smelling oil from the engine bay, then look for leaks (most likely valve cover gasket, causing oil to drip onto the exhaust manifold), or it's that open element filter you have for your breather (most likely...). Neither is a big deal, and easily remedied. 


fwiw, cis-l cars used unheated o2 sensors. you can get a bosch universal one for $15 from autohausaz.


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## 2OVT (Sep 11, 2009)

I'm poking around now, I want you to take a look at this and tell me what sensor this is...it's jut sitting here.


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## ziddey (Apr 16, 2006)

you didn't post a picture, but my guess is it's for the upshift indicator light.


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## 2OVT (Sep 11, 2009)

ziddey said:


> you didn't post a picture, but my guess is it's for the upshift indicator light.


Oops here you go.


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## ziddey (Apr 16, 2006)

that plugs into your transmission. notice how your reverse lights don't work currently?


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## 2OVT (Sep 11, 2009)

Bwahaha that you are right my friend! I'm assuming this isn't the original transmission and that the PO swapped it thus explaining the reverse lights and sloppy shifter. The plug in that appears to be for that sensor is to small. I have a newer 8v digi in my garage and it had the same small plug in. Or am I just looking in the wrong spot dear lord, I need a bently for the mk2s 

Edit: well I adjusted the idle speed screw and it's set at no more than 1100 ATM. Doing this made it so it doesn't shoot up anymore, but it sill seems as if the car is running lean and still kinda chugging a tad after firing it up. It's now more of an unburnt fuel smell. I still haven't checked for vacuum leaks yet but changed a fee vacuum lines and it seems to run a tad bit better. I'll make a small video of how it runs now so you can see.


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## 2OVT (Sep 11, 2009)

anyone? 

:vampire:umpkin:umpkin:umpkin::vampire:


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## ziddey (Apr 16, 2006)

you're looking on the transmission and not the engine right? 

when you pump the brakes, does the idle increase? 

sloppy shifter would be your shift linkage bushings. parts are decently cheap and plentiful for the mk2's. 

once you source all your vacuum leaks, you can try unplugging the o2 sensor signal wire and hooking it up to a voltmeter and ground. then use a 6mm long allen key to adjust the mixture until you see around 0.75vdc. plug the o2 sensor back in and see how it does.


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## 2OVT (Sep 11, 2009)

ziddey said:


> you're looking on the transmission and not the engine right?
> 
> when you pump the brakes, does the idle increase?
> 
> ...


I'll take a picture of the sensor plug-in that I can see on the trans. I checked my buddies 86' CIS Jetta and his plug-in on the trans is big too, where as my brother's 87' golf(the one we're talking about) has the big plug-in(from the harness) and the small (like my newer digi one) plug-in on the trans. Plus the speedo doesn't work. Which leads me to believe the trans was replaced sometime ago and it was with a newer 8v one? Maybe I'm wrong, like I said, it's an assumption. 

Edit: fired car up, let it warm up and start to idle, pumped brakes, and the car starts to kinda idle down and start to drop depending on how much you pump them. Here is the picture of what, I was talking about.


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## dkfackler (Feb 8, 2010)

ziddey said:


> ...6mm long allen key to adjust the mixture until you see around 0.75vdc. plug the o2 sensor back in and see how it does.


 
It's a 3mm Allen.


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## dkfackler (Feb 8, 2010)

That trans is older than your car. Your harness is for the new BU light switch which can't be used on this trans. You might be able to finesse the wiring to make it work. The BU light switch in the older cars is of the simple normally-open type. 

You might jump the wires in the harness with the key on(not running) and in "reverse" until the lights come on, then make a pigtail adapter to connect it up to the switch. That way, you don't alter the harness in case you get the 'proper' gearbox at some point. 

As for the idle issue: 

The AUx air valve(AAV) can be tested(engine COLD-- like sitting overnight) by starting it up and pinching the hose running from the intake manifold(near the cold-start inj) to the AAV with pliers. If the idle drops off, the valve is open-- as it should be. It will close slowly as things warm up. You can buy a bit more time for the test if you unplug the wire harness from the AAV before starting the engine. There is an electric bimetal strip which starts closing the valve soon after startup. 

If you do this with the engine warm, there should be no change in idle RPM as you pinch the hose.


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## 2OVT (Sep 11, 2009)

dkfackler said:


> That trans is older than your car. Your harness is for the new BU light switch which can't be used on this trans. You might be able to finesse the wiring to make it work. The BU light switch in the older cars is of the simple normally-open type.
> 
> You might jump the wires in the harness with the key on(not running) and in "reverse" until the lights come on, then make a pigtail adapter to connect it up to the switch. That way, you don't alter the harness in case you get the 'proper' gearbox at some point.
> 
> ...


I will have to give this a try. One a side note, I was using my ear poking around checking for leaks and I found out that the 4th cylinder fuel line was causing the hissing. I push it forward towards the valve cover and it stops...I let go it stays stopped and car runs a great deal better, but I think somethings still funny. The 4th line sometimes moves back or at least that is what it seems, we let it run for a few shut it off and it did the same thing. I pushed it back forward and it seemed to help some. I tried tightening up the (rubber?) nut dealy that holds it on and nothing really helps. I guess I could just take a video lol there is also a weird buzzing sort of noise coming from that fuel dealy on top of the air-box. Is this normal?


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## ziddey (Apr 16, 2006)

fuel injector o-rings are a common problem with these cars, and are particularly nasty since they can cause leanness in specific cylinders.

make sure you get viton o-rings to replace them with (green ones). the injector puller tool is pretty handy too, although the job is still a bit of a bitch. get ready to bleed


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## 2OVT (Sep 11, 2009)

ziddey said:


> fuel injector o-rings are a common problem with these cars, and are particularly nasty since they can cause leanness in specific cylinders.
> 
> make sure you get viton o-rings to replace them with (green ones). the injector puller tool is pretty handy too, although the job is still a bit of a bitch. get ready to bleed


Oh boy, I haven't done any of this before. But it doesn't seem to hard. You think that is what is causing all these problems? Ughh, I have to put on an alternator belt too, the other one broke :banghead: I'm kinda worried I messed with the speed idle screw then if it is this o-ring doing the damage. Any advise on how to properly re-adjust this? haha :facepalm:


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## ziddey (Apr 16, 2006)

people say not to mess with the mixture / idle screw since it's likely to mask an underlying issue. no matter. once you've fixed everything, you can then reset again.

the fuel injector o-ring replacement job isn't "hard" per say. but it is a pretty big pain in the ass.

you need to pop the old injectors out. the tool definitely helps. but even still, you need to use a flathead or similar to operate it. if you're not careful, and it seems you can never be careful enough... you'll slip and gouge yourself. i was bleeding all over the place by the time i was done.

then, once you do get all the injectors out, you can simply cut the old o-rings off. but sliding the new ones on is again a huge pain. you need to clear the air-shroud collar, which will leave your fingers extremely sore. some wd40 or other lube helps, but will also cause you to slip a lot more. again, PAIN!!

it's up to you if you want to replace the lower injector cups. most mechanics recommend not doing so, since they tend to be brittle and it's likely for pieces to fall into the head. I did it once and it was fine. The old cups tend to crack, causing your injectors to wiggle, and there be to a poor seal for the air-shroud function. But as long as you have good main o-rings, there won't be a vacuum leak.

the main holders are brass and don't need to be replaced.

Then, it'll take quite a bit of force to pop the injectors back in now that you've got fresh o-rings.

definitely one of the things I do everytime I get a cis car. love/hate thing.


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## 2OVT (Sep 11, 2009)

ziddey said:


> people say not to mess with the mixture / idle screw since it's likely to mask an underlying issue. no matter. once you've fixed everything, you can then reset again.
> 
> the fuel injector o-ring replacement job isn't "hard" per say. but it is a pretty big pain in the ass.
> 
> ...


 What kind of o-rings should I get? I guess I'll have to run up to O'Reilly's today =/ man, I really want a Bentley. I really hope this fixes it!


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## ziddey (Apr 16, 2006)

not sure if oreillys would have the ones you want. you want viton. boschs are vitons too.

i know when i last did mine, the local dealership didn't even have any in stock. The local vw specialty shop charged an arm and a leg, but in the end, it only came out to a little more than online with shipping and all.


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## dkfackler (Feb 8, 2010)

I use a bit of high-temp grease on the injector to get the ring on, and then a bit on the o-ring itself to help get it into the cup. You'll feel it 'pop' into place-- they don't go in very far. 

If it's really stiff, you can use a long, large-ish screwdriver and a smallish hammer to help tap the injectors home. The angle can make it a bit tricky.


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