Also does anyone know an easy way to fix the fast 90mm from sticking? What was the reason for it sticking? I'm thinking of fixing it myself rather than send it out to FAST.

 

I pulling my hair out trying to figure out why I can't get the IAC counts in the 30-50 range! Everone has hp tuners and I have ls1 edit, so a lot of the information I'm reading isn't helping. What table on ls1 edit sholud I play with to try to get them to come into range and by how much at a time should I change them?

 

OK, we are trying to help you man.

First, I never changed any tables in HPTuners to get the IAC counts in line.

Second, I really think you need to verify your IAC motor is even working BEFORE you start worrying about where the numbers are. Seriously, 0 IAC counts at WOT and part throttle does not sound correct.

Regarding the TB sticking, there are threads out there about it, try a search for '90mm stick'. I just did and found you this:

https://ls1tech.com/forums/showthrea...ght=90mm+stick

 

Well your pcm is telling the IAC motor to go to 138 but it's staying closed at zero. You may need a new IAC motor, or it may be a wiring problem, or maybe a bad connection. What I would do is find someone with an f-body in your area and swap IAC motors with them and see what happens.

 

You are still going to want to drill a hole in the throttlebody. This will help your car run even with a dead IAC motor.

 

Not trying to be a dick guys so sorry if I sounded like it. I've just been so frustrated with all the problems I've gotten with this damn FAST crap. I really appreciate the help guys!

I'm gonna order a new sensor tomorrow just to confirm whether or not it's the problem. I know I could check the resistance with a multimeter but **** it I'll just get a new one.

I was thinking, you guys think if I drill a hole that there may be a way to bypass the IAC all together? Also if I'm going to drill a hole how big a bit should I start with?

Thanks again guys!

 

This is gonna sound stupid but the connector is plugged all the way in and the wires aren't damaged right? It just seems weird that the iac motor would fail just cause you moved it to a different throttlebody.

As for bypassing the IAC, yes you can do it but you may find that it's not as smooth to drive while shifting (rpms drop too fast between shifts) and at parking lot speeds (letting off the gas throws you forward). But if you still have the old tb, start with that size hole, I don't remember what size off the top of my head.

 

Yeah thats why I don't think the IAC is bad cause it was fine in my old throtlebody.

Well I run a th400 with a 4200 stall so shifting and the car lunging foward will not be a problem.

What do I have to do to bypass the IAC?

 

Oh I didn't know you had an auto. Well then the stuff i mentioned won't be a problem, but you may have trouble getting it to idle in both park and drive at the rpm you want because drive wants more airflow for the same rpm. With no IAC it can't regulate the airflow. Another thing is your idle speed may vary slightly with weather conditions.

Besides drilling the tb and messing with the set screw so you're getting enough airflow, I think all you'd have to do is delete the error codes it will throw.

 

I still wouldn't give up on your IAC yet. It's either a broken IAC motor, a wiring problem, or a tuning problem and you still don't know which one it is.

As far as what table could cause this, if someone had messed with your IAC vs effective area (putting in numbers that are too big all the way across) then that could keep your iac shut all the time. Also the max desired iac position could do it too i guess. But those can't be it cause you said your desired is 136. I think that rules out a tuning problem.

Did you try your friend's IAC motor on your car? I know you tried yours in his. That would rule out the IAC motor problem.

The only other possibility is wiring, either that or your new tb is machined wrong in a way that doesn't allow the IAC plunger to retract (unlikely).

 

I'm 90% sure its a tuning issue. I've checked the wires with a multimeter and everything checks out. It was fine the day before I installed the intake. I just have to figure what tables to mess with and in which direction to change the numbers but honestly I could care less about perfect drivability. With a th400 and a 4200 stall I don't have the most streetable car anyway. All I want is to keep the car from surging so bad that the car cuts off. Which it does mostly on cold starts and when I put it in gear.

So should I just disconnect the IAC to bypass it or what?

 

Well go ahead and try it and see how you like it. It's not like it's irreversible or something.

 

Well go ahead and try it and see how you like it. You don't even have to disconnect it since it's not responding anyway, just drill/adjust your throttlebody till you're getting enough air. It's not like it's irreversible or something.

 

How do I know when I'm getting enough air? I'm running SD so what should I look at on auto tap to tell me when I'm getting enough air?

 

hey man, if oyu have hp tuers shoot me an email and tonight ill send oyu my idle configs u used to get my car and everyone elses car i tune set up at idle.

budchevy358@yahoo.com

also can you summarize whats going on right now, im at work and i dont have much time to read over it all but just hoping i can help you out some. ive been through a lot of different problems when idle tuning and hopefully yours is one of them lol

 

also why would he drill his tb hold bigger is the iac count is 0, bigger hole will let in more air and make it want to close more, and drilling is irreversable. all that should be done is setting the set screw up right.

 

Is this a 98 car?

 

His count is probably zero since the TB blade is open too far. Fix the sticking TB by sanding it with some sandpaper in the location of where it is catching. It took me 20 mintes to make mine perfect. I would do this first. My TB is open 0%. Also what did you do to take up the slack in the in the throttle position sensor? I used a piece of black electrical tape over the shaft so it wouldn't have any slop in it. Also check the Throttle body position voltage. Mine was over .65 with the blade completely closed. I oblonged the bolt holes to adjust the position of the sensor to get the voltage down to .41 with the blade completely closed.

 

also do a search or look for 90mm TB users by Phil99Vette (username) he has solved this issue completley

 

also do a search or look for 90mm TB users by Phil99Vette (username) he has solved this issue completley. Or just private message him, i did and he is still helping me though. The thing is my car idled fine and ran fine..we tried to modify the steps vs. mm squared table for the TB and the car didn't like it at all. So i left mine programmed to stock for now..working on some new stuff though