Are IAB valves always this slow?

[OrLackThereof]

My old one, I could rev the motor and it would take it 10 seconds or so to finally reach an idle. It was ungodly slow. So I bought a new one figuring the old one was bad, and I still have the same problem. Is this just a poor design or a very slow motor?

I left the valve assembly on but disconnected the motor. I disconnected the motor with the car off so the valve is stuck closed now. Car seems to run fine....and it revs up and down nice and quick, like a carbed car.

There aren't any problems with doing this right? I don't see how, since it's a VALVE, not a sensor....and its only purpose is to allow air to bypass the throttle blade. My idle is sufficiently high so it doesn't stall. And man, does it sound mean cruising around the parking lot.

 

[leakyfaucet]

I wondered this too. I've disconnected mine because of idle surge and I'd rather keep it off. The only problem I can see is that it doesn't idle high when it's cold, but I'd like to hear other opinions on it too.

 

[Mavrick]

Ya.. could we not ditch the IAB and adjust the idle solely with the screw underneath the TB?

 

[leakyfaucet]

I'm considering doing it, but I it might cause a trouble code. Plus I don't like loose wires just hanging around.

 

[OrLackThereof]

The only bad experience I've had with doing it so far is the car kicks back when you go from cruise to deceleration....and because it's acting like a carburetor without a choke, putting it into a steep gear, like reverse, from an idle can be a little tricky without stalling it or making it surge its way into a stall. No trouble codes yet though...the computer doesn't even notice.

Someone else just told me my problem might be in my TPS though, so I'm gonna check it out...I've messed with my idle screw a lot and maybe that threw the base TPS voltage out of whack and screwed everything up.

 

[MOTORCITYSTANGS]

no...it should not cause a promblem code, but you might have hard starts on cold days, and stalling out if you hit the brakes hard suddenly

 

[HISSIN50]

i will toss this out for whatever it is worth..... have you checked your vacuum? a vac leak will cause hang ups and very slow return to idle.......

 

[OrLackThereof]

Already checked ALL the vacuum hoses...found the final leak. It was on the return line from the charcoal can, so I plugged the manifold fitting and left the line open to the air.

And I think the problem might be solved...I've messed with my idle stop screw a LOT without thinking twice about the TPS. Apparently, that screws with the TPS reading. Gee, nice to know this now.

 

[HISSIN50]

yep. as you adjust the idle stop, it moves the throttle blade slightly, thus affecting the resting return on the TPS.
according to a few old timers, the TPS setting does not matter. most seem to think it does; i am not smart enough to say one way or the other.