whitacre

Ok so i cleaned my ISV, let it thoroughly dry, and put it back on. Then the car was going nuts. It would die, idle at like 100rpm, when i would rev it up and hold it at about 2500, it would like, cut gas and the tach would drop, and then go back up to 2500 but it sounded like it stopped getting gas or something. So anyway i tried to start it a few times, reset the moto, finally it starts up sorta alright and idles about normal, but when at running temp after i start it, it idles at like 600rpm, isnt that too low? Isnt there a way to make it give it more gas or something when its idling? I know its had a dirty ISV for many many years, so im wondering if its just trying to work itself out here.

Now i see smoke coming from the engine, and it smells to me like antifreeze. Im sure i have a leak somewhere, or something.

Then i was wondering what temp my electric cooling fan is supposed to come on at...i noticed it wasnt on when it was idling at about 60c give or take 10...whatever normal idling temp is for now.

And the surging went away with the old FPR, but now when i depress the accelerator, it like thumps into going forward, and when i release it, it thumps and starts to decelerate. I thought that would go away with the new FPR, but i guess im wrong?

Any ideas guys? I would like to make her happy and runnning, but im all out of my knowledge bank.

MarkPan

<trying to remember>

start it up, get it warm.
pull the green wire from the coil
adjust idle to 720 +/- 50 rpm, with the screw at top of throttlebody
replace green wire on coil

uh.. i think thats it ;-)

whitacre

where is this coil? and where is the throttle body...is it near the ISV or somewhere totally odd?

It seems to be doing ok now, its ilding about 700-800 rpm when warm. Is that about normal?

CARSNPLANES

A proper working ISV should give you the proper idle speed. Many people "play" with that Aux idle screw on the throttle body to try to get the engine to idle to mask vacuum leaks or a malfunctioning ISV or some other problem. With everything working correctly, that screw should be screwed in all the way (closed. Maybe there is a problem with your mixture,or signal from ECU, or ISV temp sensor or controller, or wiring to ISV. Don't use the screw to "fix" your problem.

5000CDQturbo

my two cents ... I wouldn't be doing anything else until you have eliminate the ISV as the problem. Perhaps you have cracked a hose causing a vacuum leak ? whenever I clean my ISV I usually put a little squirt of wd 40 or mineral oil. ( or go to a wreckers and get another ISV.) You must eliminate this problem before you start adjusting this and that.
dm

RB-200 20v

I second that! Do not mess with the idle screw or, based on my experience doing so, you'll end up with more trouble than you can imagine, when you change throttle plate position you change it's relationship to the throttle position sensor and then it's relationship to..... It took me weeks of trial and error adjustment to finally get things kind of close to where they should be. FWIW, I didn't do it to an Audi, but the engine management systems on any modern fuel injection vehicle are roughly the same. Look for simple solutions, bad connections, open vacuum lines, etc. Good luck!

nuugen

The green wire is the switching negative side of the coil!! I agree w/the others, the idle screw should be turned all the way in and the real cause of the prob should be located...Use SJM Autotechnik site for an in-depth database on diagnostic and troubleshooting these motors..<ul><li><a href="http://www.sjmautotechnik.com">SJM Autotechnik</a></li></ul>

whitacre

well i didnt mess with anything, and it seems to idle at the right speed now...so all is well..the only thing i still have to do is crank for a few seconds and sometimes even have to give it a little gas before it starts up and then all is fine....but she rides really nice...its quite a good car again.

MarkPan

" Adjusting the Idle Speed

Once you have determined the ISV Control Unit is working ok, Start the engine and let it idle, don't forget that the engine should be warmed up, the manual transmission cars should idle at 720 +/- 50 RPM, automatic equipped vehicles should idle at 800 +/- 50 RPM. If not, then use the adjusting screw on top of the throttle body to adjust the idle speed. Now un-plug the green wire from terminal 1 on the ignition coil (86-88 5000TQ, single knock MC). This activates the idle stabilizer control unit preset value. Look at the DMM and read the mA displayed, you should see 430mA +/- 20mA. Now reconnect the terminal 1 green wire or connection and check the DMM reading again, you should see 430mA +/- but now the reading mA current reading should be fluctuating a little as the Idle Stabilizer control unit adjusts the current flow into the ISV to adjust the idle speed."

I thought the engine would die too. It didn't though, I'm not sure how that works...

TonyOldSchool

OK so what did you do? Sometimes I think it fixes itself!