IWTF = Idles Way Too Fast

I went through the procedure in Car Craft (or was it Hot Rod?) that featured Tom Keliher's car. You know, the one that showed how to set minimum air and TPS.

No problem. It went just fine. My minimum air was way off, because the car wouldn't even start with the IAC closed and disconnected. I got it set, though, and reset the TPS. The car starts and runs just fine, but immediately after startup it idles waay too fast! The engine will eventually slow down to the correct speed, but it sure takes awhile (many seconds).

Before I did this, the car also started and ran fine, but didn't over-rev like it does now. If you don't wait for the engine to settle down before putting it into gear, the tranny "hits" pretty hard. It acts like the IAC has some kind of default starting position (open some amount) and the ECM figures out that that's too much and eventually backs it off.

Am I missing something or is this how it's supposed to work? I haven't tried resetting the ECM, yet. Would that "fix" it?

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'87 IROC 5.7l TPI - original owner!

 

I was actually thinking "computer reset" as I read your message.

The same procedure applies for the Multiport V6, so: I still don't understand why we need to set minimum idle speed by removing the plug over the throttle stop. If the factory set it where it should be, and then plugged it up, and nobody's touched it yet, then why should we play with it??


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

 

What happens if you swap cams or throttle body? Then you will have to adjust it. that's a couple reasons, I'm sure there are many more.



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86 Camaro Sport
383 Speed-O-Motive Crate Engine, Trick Flow Heads, 58mm Accel TB, 3.73 Auburn Pro, SLP Cold Air Induction and Headers, Dynomax Cat-back, Serpentine belt setup, Dual IROC Fans.

http://www.sethirdgen.org/octride.htm

 

PJ that is normal for that computer ......thats why somone messed with it by closing the throttle plates giving the ecm less idle speed control ...i see this all the time .........up grade to a newer computer setup or learn to love it

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87GTA,350,Auto,MAF screens removed,195 thermostat,cold start injector UNPLUGED,K&N,modified air intake,ADSchip,3:70s,3inch cat back Flowmaster single outlet,TPS.54,Bosch Plat plugs,base timing 6BTDC,22 MPG,what a ROACH,Bilstiens in the rear....,don't let yer meat loaf

 

Who is "someone"?

Closing the throttle plates gives the ECM more control, doesn't it?



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'87 IROC 5.7l TPI - original owner!