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Discussion Starter #21
ok i see the connection for the o2 sensor above the heat shield, the female end is still there and looks intact i assume a good exhaust shop can mount a new o2 sensor and reconnect the catalatic converter air line which is sealed by weld i think i get the picture now of how it all was original
 

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1982 Corvette Tune-Up

ok i see the connection for the o2 sensor above the heat shield, the female end is still there and looks intact i assume a good exhaust shop can mount a new o2 sensor and reconnect the catalatic converter air line which is sealed by weld i think i get the picture now of how it all was original

If you still have the original stainless steel "hedders" on it you'll see where the pipe attaches that goes back to the side of the catalytic converter. Your air valve on the engine will send air one of two ways.........either into the exhaust manifolds or into the catalytic converter. And the O2 sensor is supposed to screw into the pipe just ahead of the catalytic converter. Did you find the EST wire yet? It's behind the distributor and I believe it's an 18-gauge brown wire that has a connection in it's middle. You disconnect that wire when you adjust your initial timing so your ECM isn't controlling the timing. Then be sure to plug it back together again.
 

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Discussion Starter #23 (Edited)
not sure single wire yellowish in color single brown connector more two right of distributor close to it, there is also one behind distrib single also but red, it looks like it goes to wiper motor
 

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Discussion Starter #24
also friend you stated tps switch is to be set at 525, the car has the original if i buy new will it be set or will i have to set, slso from time to time i have the classic idle surge symtoms but it stops pretty soon after driveing a whole other set of challenges
 

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not sure single wire yellowish in color single brown connector more two right of distributor close to it, there is also one behind distrib single also but red, it looks like it goes to wiper motor

The EST wire is behind the distributor and about 6" toward the driver's side. It is a small wire and has a brown "locking" connector on it. If you unplug it and your engine slows down then you've found the right one. And the TPS switch doesn't come pre-adjusted. Once installed it must be set to .525 volts (slightly more than 1/2 volt).
 

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Checking/Setting The TPS Voltage

ok found it then how do you adjust switch to .525 volts

Of the three wires going to it the center wire is the hot and the bottom wire is the ground. Many years ago I stripped a 1/2" section off the insulation of each of those two wires then soldered the strands so they would be rigid and not fray. Makes it real easy to hook up my digital voltmeter. But don't strip them one directly above the other. Stagger them at least 1/2" so they can't make contact with each other. Then with the throttle closed set the voltage to .525 volts (plus or minus .025).
 

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Discussion Starter #28
ok then re seal them with black tape, did you read my post about the idle surge from time to time, my first order of business will be to replace exhaust back to stock with o2 sensor, timing,and coolant temp ecm sensor i should see an improvement dont you think
 

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Idle And The IAC Motors

ok then re seal them with black tape, did you read my post about the idle surge from time to time, my first order of business will be to replace exhaust back to stock with o2 sensor, timing,and coolant temp ecm sensor i should see an improvement dont you think

As the throttle bodies don't have any replaceable bushings for the shafts the bodies slowly wear out and then air can be sucked in thru the sides of the shaft. The bodies can be bored and re-bushed by DCS in Arizona. Also there is an IAC motor in each of the throttle bodies (the Tuned Port engines only use one) and both of them must be working for the idle to be smooth and not wander. Quite often simply removing the IAC's and spraying carburetor cleaner in the bore will clean off the built-up oil/carbon deposits that form around where the pintle seats (the tapered-point stem of the IAC). Those IAC's are what controls the idle speed as they will open and close to regulate the amount of air flow into the engine. Looking down from the top you can see the tips of those IAC's and when you "blip" the throttle you'll see them move.
 

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Discussion Starter #30
ok IAC motors? what does IAC stand for are they a seperate part in the throttle body i would like to see a picture, spraying the cleaner remove them or spray in place. have no idea were IAC motors are will have to study throttle bodies, and yes had heard about the issue with the worn out bushings and have seen new rebuilt ones on line, your car must be tiptop what color is it i should track down a original twin throttle body service manual on ebay
 

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Discussion Starter #32
ok to broke to retire,{ idle air control} there is one on ebay unplug and unscrew right? then clean up with cleaner tappered end that seats, also found service manual bought it it should have some pictures and info, also see rebuilt throttle bodies for about 200 bucks i can see that this system is complicated but simple if you know what to look for can i ship the car to you?
 

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IAC Motors

you got it

You can buy new IAC's from every parts house in the country.

When you go to screw an IAC in make absolutely sure it's pintle is retracted enough to allow it to be tightened. As the IAC is a "stepper" motor the motor can run both directions. To retract the pintle hook the wires to it and ground the housing (or screw it in part way). Then when you turn the key on it'll fully retract. Just don't force it or you'll damage it. You can see if it's fully retracted by looking down into the 3-sided hole above it and see the pintle tip.
 

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Discussion Starter #36
ok i was looking at it today down the three sided hole i just see a hole down there the car is not on not seeing anything what position is that retracted? also my car has a electric cooling fan close to radiator in addition to the belt drive fan is that stock or added on
 

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Discussion Starter #37
also friend a note to the electric fan, it is on all the time even when i first turn the key on to pre crank what do you think pal?
 

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More On IAC Motors And Electric Fan

also friend a note to the electric fan, it is on all the time even when i first turn the key on to pre crank what do you think pal?

When you look down into the "three sided hole" in the top of each throttle body you'll see a hole at the bottom/front that is about 3/8" diameter. If you don't see anything stuck into that hole from the front side then the pintles are retracted. With the IAC's removed you can stick your finger into the throttle body and see your fingertip from the three sided hole.

Now on to the electric fan. The fan should only run when the temperature exceeds 230 degrees and it's kicked on by a two-terminal switch that is screwed into the right cylinder head just above the #8 and #6 spark plugs. One of the wires going to that switch should be hot and the other will be hot ONLY when the temperature exceeds 230 degrees. It's impossible to see that switch from the top so you'll have to jack it up and crawl under it to see it. And even then it's hard to see because of the heat shield that covers the #8 and #6 plugs. Take that heat shield off and it's easy to get to.

In the 23 years I've driven my '82 I have only heard my electric fan kick on one time and that was when I was in Death Valley where summer daytime temperatures often exceed 120 degrees.
 

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Discussion Starter #39
ok great another issue is that fan switch a plug in type and where can i find a new switch is there any other systems that can be sending false temp readings to cause that fan to be on all the time
 
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