Number68

ok, well i've been in the process of readying my 5kt for nj state inspection, I replaced all the bad bulbs and gave her a thorough cleaning and reassembly today, on the list still is:

-Re-install ignition switch
-re-wire the horns(and restore them while I have them out, man those things are friggen rusty. it's been so long since i had a horn, I forget what they sound like)

- stop my alt belt from coming loose(I removed the tie-rod looking thing a few months ago, thinking it only had any effect on the ac compressor, but since then my belt keeps coming loose)

- and last but not least, and the point of this post I want to try and get her to idle smoother(which has been an ongoing battle since I replaced all my vac lines and such)

When we first bought the car like 3 years ago, she idled perfectly at 800, but was definitely lacking on power. Then as I learned more and started fixing things, she slowly started idling like crap. The idle screw and the metering head mixture screw both had definitely been messed with multiple times in the life of this car...

I went to check my CO adjustment(the metering head screw) the other day because I was having ISV problems, it had essentially stopped working so I just unplugged it and used my idle speed screw to keep the car idling till I got home. I cleaned my isv with throttle body cleaner, and it started working again so I went ahead and started to test things.

I know in theory the idle screw should be screwed all the way in, and let the ISV do it's job. This of course means that everything should be in good working order.

I turned the screw in as far as I could while it was running (and still have the throttle plate move) and the car started running like ****, and it wouldn't start in that position. so I put the screw back at where she idled happily around 750rpm and went to check my CO%/Duty Cycle. I don't remember the exact number right now, but it was a bit lean. I had a b*tch of a time getting it to be around 46-52% because of how irradic it was. Even now according to my NB AFR it is still all over the friggen place, going slightly more lean than I would like too.

and now I still have the same problems I was having before, that is when I go to hit the throttle it will stutter/miss a bit (according to my gauge, goes way lean) and then it will catch up and start going good. and if I rev and let of the gas real quickly it will bog down like she wants to stall until it catches back up, this might just be the effect of my BPV, but who knows.

now this is what I'm thinking... My metering plate could be sticking, there is a way to pop the control pin out and clean it up, or my CO/idle speed mixture needs some drastic messing around with.

I was thinking that if I were to put my idle speed screw in all the way, forcing the car to run crazy rich (I think it was at like 30% duty) and then try to get the CO back to where it should be I could get rid of these problems, this is assuming I'm not overlooking something though...

what says you guys?

Number68

I just started her up for a short drive, and ran it through all sorts of accelaration tests...
A little hesitant on starting cold, had a bit of a miss and such for a second or two, but then started idling perfectly. and then drove flawlessly, no hesitation or stumble..

this was on a cold motor though, I was in a rush and didn't let it warm up like I usually do, so apparently the CSV/WUR are playing an effect in this too

audi_marv

I always thought the idle screw at the front of throttle assembly should be screwed in all the way only for Non-Turbo's, and that on Turbo's the screw should turn out 1-2 turns for proper idling.

Also told by audi techfanatics that the mixture setting should be set at roughly 40-42%...that these cars prefer a richer setting. Yes the book says 46-52%, but that was for a new car 20+ yrs ago.

Your WUR could be responsible for the loss power feeling, or a bad Air Temp sensor at your intercooler.

Some throttle body cleaner on the air plate should help, along with some techron or seafoam in the tank.

Sounds like your real problem may be your O2 Sensor....that its lagging behind in making the adjustment as you're hitting the accelerator, causing the stutter, and then finally running clean.

Number68

yea, I'm leaning towards thinking it's an o2 problem I want to pick up a new one just to get that out of the picture. It's time I check out how my wur is doing too, that and the csv are two things i've never futzed with. I know my IAT is good, i've tested it on numerous occasions, and just resoldered the wires on it recently. That's why I hate this problem so much, I fix something that might be a cause, problem goes away. hey I fixed it, next day, it comes right back... I want to set it a little richer, this cars run lean as it is, once I get my new o2 in, and I pass emissions, i'll richen it up a little bit....

Number68

also, for those that care i've been having a pretty good discussion on another forum, it's basically been narrowed down to either bad o2, sticking control pin, or a random vac leak. one day in the next week or so I will pull my WUR and clean it out, I know they can get kinda gunky. same with the isv control module. I just dont want to do it when this is the only car I have on campus...

note to mods, i'm not trying to advertise, just trying to help spread information.

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