In this tech article, the author says to paper clip the A and B terminal on the ALDL box... turn key to on position, wait 30 seconds, then disconnect the IAC.... then he says to start the engine.

My question is.... after disconnecting the IAC, do you also disconnect the paper clip and THEN start the car or do you start the car with the paper clip still in there???



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1986 Trans AM
355 TPI
4 Wheel Disc Brakes
9 bolt Borg Warner Rear (2.77's....oh joy) :P
6" rods, approx. 9.7:1 Compression, Stock TPI (soon to be ported), 24#/hr LTI injectors (cleaned and flowmatched by Cruizin Performance), Hedman Shorty Headers, 3" exhaust with 80 series flowmaster, SBC 993 heads completely redone and modified for 1.6 RR, 1.52 RR (for now), Comp Cams XE262-14 TPI Cam, Holley AFPR, TPIS airfoil, MSD wires, MSD 6-AL Ignition, Hypertech 53,000 volt coil.

Track times to come.

 

In this tech article, the author says to paper clip the A and B terminal on the ALDL box... turn key to on position, wait 30 seconds, then disconnect the IAC.... then he says to start the engine.
My question is.... after disconnecting the IAC, do you also disconnect the paper clip and THEN start the car or do you start the car with the paper clip still in there???
you would start the engine WITH the clip in.
this is to fully seat the IAC pintle and run
the engine from the throttle plates. if closed
too much idle will be below 400rpm. if idle is
too high idle down to 500rpm.
the IAC is a controlled vacuum leak. this will
increase or decrease according to load.
if a/c is on, wheels at full lock, or in drive.
the IAC will open more to compensate for
lower idle speeds.
airdeano

 

i thought u shouldn't ever start a car with A&B connected.

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- David
88' GTA 5.7L TPI MODS---> air foil, K&N, Shift Kit, 180* therm, TB bypass, Gutted CAT, Flowmaster 80 Series Muffler added to Unkown CatBack, Ported Intake

http://www.geocities.com/david_angel_16

 

Ok.. one person says to leave it in and the other says to remove it. I posted this topic over in the Tech/General section and the guy that posted there said that after I disconnect the IAC I should remove the paper clip before starting the car. Now I'm definitely confused.


------------------
1986 Trans AM
355 TPI
4 Wheel Disc Brakes
9 bolt Borg Warner Rear (2.77's....oh joy) :P
6" rods, approx. 9.7:1 Compression, Stock TPI (soon to be ported), 24#/hr LTI injectors (cleaned and flowmatched by Cruizin Performance), Hedman Shorty Headers, 3" exhaust with 80 series flowmaster, SBC 993 heads completely redone and modified for 1.6 RR, 1.52 RR (for now), Comp Cams XE262-14 TPI Cam, Holley AFPR, TPIS airfoil, MSD wires, MSD 6-AL Ignition, Hypertech 53,000 volt coil.

Track times to come.

 

Originally posted by 86TpiTransAm:

The person on the other board was me, and by the way I'm not a guy, I'm a girl. Anyway, dooon't start it with the paperclip in the ALDL, it's not a good idea, can possibly fry the computer that way (at least that's the rumor). So just try it by removing the paperclip before starting it.
Think about it: you insert the paperclip and the IAC moves closed. Then you unplug the IAC. Whether you remove the paperclip before or after starting the engine makes no difference to the IAC because it's already unplugged and can't move. So don't risk frying the computer. You'll know if it works because the car will be idleing really low, like 450 rpm. Also, I don't know if the tech article mentioned this, but do this when the engine is warmed up.


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91 Z28
Come see The Vicious...

 

Well now I'm in love. An obviously smart woman AND owner of a thirdgen. Where have you been all my life? :P lol Thanks for the info... makes much more sense the way you put it in this post. Much appreciated.

------------------
1986 Trans AM
355 TPI
4 Wheel Disc Brakes
9 bolt Borg Warner Rear (2.77's....oh joy) :P
6" rods, approx. 9.7:1 Compression, Stock TPI (soon to be ported), 24#/hr LTI injectors (cleaned and flowmatched by Cruizin Performance), Hedman Shorty Headers, 3" exhaust with 80 series flowmaster, SBC 993 heads completely redone and modified for 1.6 RR, 1.52 RR (for now), Comp Cams XE262-14 TPI Cam, Holley AFPR, TPIS airfoil, MSD wires, MSD 6-AL Ignition, Hypertech 53,000 volt coil.

Track times to come.

 

Wow, nice to hear of a samrt woman owning a f-body and not following the trend of the Rustangs. I am also in love Anyway... I agree with her, in the manual is says DO NOT START THE CAR WITH THE TERMINALS JUMPED... so, I imagine its not a good thing. What is the problem with the IAC valve anyway?

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1988 Pontiac Trans Am GTA L98 5.7L, Black on Black with 114,000kms.

Best ET 14.559 @ 95.25MPH
Custom 3" Stainless Exhaust Y-Pipe back (High flow Cat and Flowmaster Mufler)

 

There is no problem with the IAC valve.... you're supposed to unhook it to properly set your idle. There's an article about it in the tech article section of the main page.

 

ok, so wouldn't it mean that ur not realling setting ur idle, ur setting ur minimum air flow through ur throttle blades?

------------------
- David
88' GTA 5.7L TPI MODS---> air foil, K&N, Shift Kit, 180* therm, TB bypass, Gutted CAT, Flowmaster 80 Series Muffler added to Unkown CatBack, Ported Intake

http://www.geocities.com/david_angel_16

 

In reality that's what you're doing is setting your minimum air flow... but in essence at the same time it's setting your idle.

------------------
1986 Trans AM
355 TPI
4 Wheel Disc Brakes
9 bolt Borg Warner Rear (2.77's....oh joy) :P
6" rods, approx. 9.7:1 Compression, Stock TPI (soon to be ported), 24#/hr LTI injectors (cleaned and flowmatched by Cruizin Performance), Hedman Shorty Headers, 3" exhaust with 80 series flowmaster, SBC 993 heads completely redone and modified for 1.6 RR, 1.52 RR (for now), Comp Cams XE262-14 TPI Cam, Holley AFPR, TPIS airfoil, MSD wires, MSD 6-AL Ignition, Hypertech 53,000 volt coil.

Track times to come.

 

VisciousZ: has anyone told you how hot you look staring at aan engine block? *stops the cheezy pickup lines*
okay well anyways you are very attractive Up for a date? :P

email me.

 

Hey man, this isn't a bar. LOL

------------------
91 Z28
Come see The Vicious...

 

Here is the correct procedure:

TPI Idle & IAC Valve Adjustment Procedure

· Key Off
· Attach TPS test harness
(allows multimeter to determine TPS voltage otherwise use a scanner)
· Insert Trouble code jumper
· Key On
· Wait 30 seconds
· Unplug idle air valve harness
· Key Off
· Remove jumper
· Key On, Start Engine
· Adjust Idle screw to correct rpm
· Adjust TPS to .54 v using ohmmeter
· Key Off
· Replace idle air valve harness
Remove TPS test harness


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Mike Metzler (Desert86Roc)[*] Check Out:SpeedWorldMotorplex.com[*] Check Out:Chevrolet F-Body Online Part & Illustration Manual[*] www.MetzlerRacing.com

Best ET @ 1250 ft[*] 15.352 @ 91.215 mph (uncorrected)

 

Rumor about the clip.

In the factory repair manual, you will notice that starting the car (at least in some models, ie 85) with the paperclip in will make the car enter field service mode. It will run, and I have verified it. The ECM will flash the check engine light according to the O2 readings...light on most of the time and you are rich. Light off most of the time-lean. Just like Goldilocks, if the light is on and off, the mixture is just right.

However, field service mode WILL change spark timing, and it is for that reason that it is suggested not to be in the mode while driving down the highway, or for extended periods of time. -Matt-

 

I thought you were supposed to insert the paperclip after starting it to go into service mode. And no, it won't necessarily fry the computer. I did it once on accident and the computer survived, thank Gawwwwd.

------------------
91 Z28
Come see The Vicious...

 

I have done it several times in the past when I have gotten drunk and worked on cars in the past and never had a computer fried. Maybe I have just been lucky.

 

iv done it to three different f-bodies, all on accident, and the first time i didn't know any better. never had a problem, but im still not gonna take any chances

------------------
- David
88' GTA 5.7L TPI MODS---> air foil, K&N, Shift Kit, 180* therm, TB bypass, Gutted CAT, Flowmaster 80 Series Muffler added to Unkown CatBack, Ported Intake

http://www.geocities.com/david_angel_16

 

You can do about anything you want to the A-B connection, and not hurt the ecm. Applying a voltage to it wouldn't do it any good, but using different resistances across the connection puts the ecm into various modes other then normal operation. If you doing anything other then using a scan tool, it's best not to drive the car in other modes. ie some are extrememly rich, and run fixed timing, carbons up an engine real quick.

 

Man!!! So much talk about ONE thing. If it is really that important to anyone and no one else here can find it, I will dig up my old Hot Rod article if anyone wants.

 

Entering Field Service Mode by paperclipping A and B after the car is on only works on thirdgens with OBD I, whatever the hell that is... I'm stupid. My 86 obviously doesn't have that because today when I started my car and then paper clipped the A and B terminals, the SES light came on and stayed on solid, no blinking... and my idle dropped about 100 rpms.... when I pulled the clip out, SES light off and engine back to where it was idling. Maybe on the non OBD I cars you have to paper clip A and B BEFORE starting the engine. I did it on accident once and noticed the SES light flashing. I'll have to try that.

Back to the original topic I posted... I've come to the conclusion that my IAC is non-functional. I came to this conclusion today when I used the previous method mentioned (waiting 30 sec, undoing the IAC, etc) and my car idled EXACTLY the same. So I dropped the rpms down to about 600rpms with the IAC unplugged, shut the car off, plugged the IAC back in, then started the car..... idled EXACTLY where I set it with the IAC unplugged. It "should have" idled higher AFTER I plugged the IAC back in.

------------------
1986 Trans AM
355 TPI
4 Wheel Disc Brakes
9 bolt Borg Warner Rear (2.77's....oh joy) :P
6" rods, approx. 9.7:1 Compression, Stock TPI (soon to be ported), 24#/hr LTI injectors (cleaned and flowmatched by Cruizin Performance), Hedman Shorty Headers, 3" exhaust with 80 series flowmaster, SBC 993 heads completely redone and modified for 1.6 RR, 1.52 RR (for now), Comp Cams XE262-14 TPI Cam, Holley AFPR, TPIS airfoil, MSD wires, MSD 6-AL Ignition, Hypertech 53,000 volt coil.

Track times to come.

 

Originally posted by 86TpiTransAm


Not necessarily. You're using the stock PROM, so your computer's desired idle is probably set for something close to 600 rpm. In this case the computer will move the IAC to the fully closed position, which is exactly where it was when you unplugged it and set the idle.

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91 Z28
Come see The Vicious...