Re: Need a pic of the FIAV blocked off
 

Good idea, I'll go do that in a little bit. I have a spare one with me too I could try. I did notice there is rtv around it from the guy before me so maybe he lost the little o-ring for it.

Re: Need a pic of the FIAV blocked off
 

If there is 1 good coil in each of those ISC motors you have, then you could build one good one, if that is the problem. It's common for 1 coil to go bad and then it don't work so good,

Re: Need a pic of the FIAV blocked off
 

Ok cool, I did try unplugging the isc while it was idle surging and nothing happened. Then I loosened up the idle switch and the idle went up to 2000. (Cause the ecu no longer knows the car is idling.) Then put it back on and it went back to surging from 1100 to like 1400. If the isc ohms out good I may try adjusting the biss screw, I might have it out too far.

Re: Need a pic of the FIAV blocked off
 

Man I just started the car. The thing idled right away without any warming up. I think I'm going to like having the ISC back in.

Do you know the proper way to set your idle? If you don't, check out VFAQ or plymouthlaser.com. Also, I have an ISC here with 1 good coil if you need any parts. If you need help soldering in the new coil or anything, let me know. I also have a spare good Black ISC sitting here if you need one. It works fine, but is the loudest ISC I've ever heard.

Also, if you have a blown ISC, there is a chance it may have damaged the ISC chip/circuit in your ECU. Something to just keep in mind.

Re: Need a pic of the FIAV blocked off
 

Yeah just I got inside from testing it. They tested out at 30.1 ohms so they are good. I turned the biss screw all the way in and it still idle surges once it's warmed up. So I must have air getting in somewhere.. I'll post a pic of where a put the rtv so you guys can tell me if I put it in the right spot or not..

Re: Need a pic of the FIAV blocked off
 

Did you set the idle the correct way? There are 2 points that you need to ground before adjusting the BISS screw.

Re: Need a pic of the FIAV blocked off
 

Ok.. after looking at the pic of which ones to block off I forgot to block off one passage..:punch:

I got it blocked off now but I'll probably just wait til tomorrow morning to let the rtv dry.

Brandon I haven't set the idle the correct way. The general rule is turn it in all the way and turn it out 2 1/4 - 2 1/2 turns and I've always gone by that and it seemed to work well on my last 3 dsm's.

It should be good to go tomorrow morning though! I'll post the results.

Re: Need a pic of the FIAV blocked off
 

Well I decided to start it up tonight. Wanted to die a little at startup like it should. Then as it warmed up it started to idle surge.... Fuck me. So I let it warm up. Shut it off started it back up, then it reved to like 2200rpm's and dropped down quickly and continue with the idle surge. I tried messing with the biss and it changed NOTHING. Idled the same no matter what. It's acting like there is a huge ass hole after the maf. So I might mess with it a little more but I wont really be doing anything worth while til I do a boost leak test.

Re: Need a pic of the FIAV blocked off
 

Do you have a boost leak? What is the base timing? It sounds like it could be lean at idle, that is why it cannot generate enough torque to develop a solid idle? (Idle consists of two things, airflow and torque management).

Which car is this?

Re: Need a pic of the FIAV blocked off
 

This is on my white one. 91 tsi, auto, stock. I can't do a boost leak test til I come back home to MN which is in 2 weeks. The car does run lean at idle. I'm pretty sure I need a new fuel filter cause at light loads (driving up a hill) I'll feel a big loss of power and the wide band goes to about 17.5 a/f. Or I was thinking it's the fpr. But that is a different problem. I can't really do anything til I boost leak test it otherwise I'll just be going in circles. And I don't know if base timing is set correctly but the car idled fine before, except it idle surged as it warmed up. But once it was warm it was absolutly perfect. Now that I blocked off the FIAV it does the opposite..

Re: Need a pic of the FIAV blocked off
 

Check your base timing. If the ICS was stuck open it could have been letting in enough air to overcome the fact that the base timing is way off. Now that you've closed up that leak the car does not have enough air to run (If I am reading your problem correctly the car will start then die?) Another problem could be a very large vacuum leak.

The fuel filter can cause a blockage in fuel flow overall. A fpr failure would be a lack of fuel under load. If the vacuum line isn't hooked up to the FPR you will not have a rising rate of fuel pressure delivery under boost.

Re: Need a pic of the FIAV blocked off
 

So my leaning out problem is probably my fpr. The vacuum line is hooked up. I have another one from my red talon to put on it i've just been lazy. Maybe I'll do that today. I did test the ISC yesterday and it's good. The car starts fine, it doesn't die. Once it starts to warm up it begins to idle surge. Before I blocked off the FIAV it would idle surge as it warmed up but once it was warm it stopped and idled perfectly. I don't have a timing light to check base timing so once again I'll have to do that when I get back to MN where I have access to one.

Re: Need a pic of the FIAV blocked off
 

You still have the ICS working? The biss does not do anything? Did it function before?

Re: Need a pic of the FIAV blocked off
 

Yup the ICS is still working. I only blocked off the FIAV. The biss no longer really does anything. It did function perfect before.

Re: Need a pic of the FIAV blocked off
 

Then you have a large leak. Does unplugging the ICS do anything? The idle surge is because you have to much airflow and cannot control it. The computer is trying to pull timing or close off the ics but is not doing it successfully so you are constantly hunting to try to control the idle air.

You can try to unplug the ICS and see if you can adjust the airflow with just a BISS.

You can also try to ground out the timing plug on the firewall to lock in the timing to a base setting, this would eliminate the computers ability to change timing (dont drive like that though as it locks in the timing at base setting if I remember correctly).

Re: Need a pic of the FIAV blocked off
 

Yeah that's what I said earlier. It's acting like I have a large leak more than a sensor problem. I've had too many idle surge experiences with other cars and now I'm getting the hang of the symptoms. Haha. But I did unplug the ISC and it did nothing, played with the biss and it did nothing. So I know for a fact I have a big leak somewhere. Last night I swore I heard a little whistling around the throttle body area and I can garentee it's the leak I'm hearing. And I haven't driven the car cause it's too embarassing and probably wont until I drive home in 2 weeks if I havent found the problem by then.

Re: Need a pic of the FIAV blocked off
 

Just went outside to play around with it. Can't really do much with only a $20 tool kit from autozone. Only thing I really tried was unplugging the maf when it was fully warm and it stopped idle surging. I really need an air compressor......

Re: Need a pic of the FIAV blocked off
 

I personally like having the ISC, especially in a DD.

Re: Need a pic of the FIAV blocked off
 

FIXED IT! Used an Amp can and cut it for a block off plate. Still using the ISC too. Now I just have to adjust the idle a little bit since it's way different with that blocked off. I played with it a little and got it to idle at 850 which I will probably just leave it at.

Re: Need a pic of the FIAV blocked off
 

Awesome. Way to be resourceful!! And why not set the idle the correct way while you're at it? You ground two spots which sets the ISC in a middle neutral position, then set the BISS screw to the correct RPM, then unground and the ISC takes over.