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Almost there... Idle question..

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Old Sep 13, 2015 | 09:38 PM
  #1  
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From: Washington State
Car: 1986 IROC Z
Engine: 305 TPI
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Almost there... Idle question..

OK, almost there guys. Got her running pretty good. Definitely drivable, some new tires, new muffler, safe and ready to go.


However, it starts right up but seems to idle kinda high until it heats up. Idles at about 1500 then slowly drops to 700 but it takes 10+ minutes to get there.? Been battling this car for months and had to have the heads redone and also had the injectors checked and TB rebuilt by Dr. Injector. I adjusted the IAC and TPS and have driven it plenty to "teach" the IAC. No vacuum leaks. Most of the other sensors are new and it's not throwing any codes..


Not unhappy with it but would like to have it start, run, and idle as it should.


Ideas?
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Old Sep 16, 2015 | 04:32 PM
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From: Milwaukee
Car: 92 Firebird, 77 Trans Am SE, 86 Z28
Engine: 5.7 HSR, T/A 6.6, empty
Transmission: T-5, TH350, T-5
Axle/Gears: 3.08 posi, 3.23 posi, 3.23
Re: Almost there... Idle question..

Ten minutes is a long time. I'd check the temp sensor and see if it correlates to the engine temperature the whole range. New doesn't mean it's correct.
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Old Sep 17, 2015 | 03:35 PM
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From: Washington State
Car: 1986 IROC Z
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Re: Almost there... Idle question..

How do you do that? With it still installed?
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Old Sep 17, 2015 | 03:55 PM
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From: Milwaukee
Car: 92 Firebird, 77 Trans Am SE, 86 Z28
Engine: 5.7 HSR, T/A 6.6, empty
Transmission: T-5, TH350, T-5
Axle/Gears: 3.08 posi, 3.23 posi, 3.23
Remember that cts circuit chart I posted awhile back? Ohm check the sensor at differet engine temperatures.
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Old Sep 17, 2015 | 04:07 PM
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Re: Almost there... Idle question..

Ah, gotcha..Thanks, will do..
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Old Nov 23, 2015 | 05:24 PM
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Car: 1986 IROC Z
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Re: Almost there... Idle question..

Well the sensor seemed to check out OK. Now I'm not so sure it's temperature related. Just got back from a short drive to town and when I got bock the idle had dropped to where it should be. Thing is, it's snowing outside and the air dam I built works really good so the engine temp didn't get very high. (Not even to the first mark on the gauge) Seems more like a run time issue and I have no idea what would cause that?
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Old Nov 23, 2015 | 06:44 PM
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From: Milwaukee
Car: 92 Firebird, 77 Trans Am SE, 86 Z28
Engine: 5.7 HSR, T/A 6.6, empty
Transmission: T-5, TH350, T-5
Axle/Gears: 3.08 posi, 3.23 posi, 3.23
Re: Almost there... Idle question..

So I get this right.....it idles high for a long time no matter the coolant temprature? Does it always go to normal low idle after you've driven it long enough? I would want to verify the wiring and connections from the ecm to the temp sensor is aok. It would be great if you had a proper scanner to see what the iac counts are at.
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Old Nov 25, 2015 | 07:29 PM
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From: Washington State
Car: 1986 IROC Z
Engine: 305 TPI
Transmission: Auto
Re: Almost there... Idle question..

Yeah, it's weird. It will always eventually idle where it should. I just thought it was heat related but because it went from hot to cold here quick, I don't think so. Any scanners you would recommend? All I've used is the ole' paper clip ...
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Old Nov 25, 2015 | 08:29 PM
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From: Milwaukee
Car: 92 Firebird, 77 Trans Am SE, 86 Z28
Engine: 5.7 HSR, T/A 6.6, empty
Transmission: T-5, TH350, T-5
Axle/Gears: 3.08 posi, 3.23 posi, 3.23
Re: Almost there... Idle question..

The only good scanner I used was the old Snap On red brick....http://www.ebay.com/itm/Snap-on-MT25...-/262106289659 It's not made anymore but it's findable cheaply. I'm sure there are others, even newer ones but I never used them and I'm sure newer ones the price goes up.
I moved to EBL P4 so I run a laptop as a scanner, no need to have an obd1 scanner anymore.
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Old Nov 26, 2015 | 02:22 PM
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86IROC112's Avatar
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From: Washington State
Car: 1986 IROC Z
Engine: 305 TPI
Transmission: Auto
Re: Almost there... Idle question..

I was thinking about buying this cable so I could do a full datalog on it? Thoughts?

http://www.moates.net/aldu1-and-cabl1-p-127.html
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Old Nov 26, 2015 | 02:51 PM
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From: Milwaukee
Car: 92 Firebird, 77 Trans Am SE, 86 Z28
Engine: 5.7 HSR, T/A 6.6, empty
Transmission: T-5, TH350, T-5
Axle/Gears: 3.08 posi, 3.23 posi, 3.23
Ah good find, I forgot people use that. I'd search the boards. Tons of info should be out there. I've never ran it myself.
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Old Nov 26, 2015 | 02:59 PM
  #12  
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From: Washington State
Car: 1986 IROC Z
Engine: 305 TPI
Transmission: Auto
Re: Almost there... Idle question..

I found it here: www.scotthansen.net

Ever heard anything about him? Seems like pretty knowledgeable guy.. I can do the datalog then email him the results then he can re-program my chip based on the results. Probably needs it anyway since all the smog crap including the CAT has been removed..?
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Old Nov 26, 2015 | 10:05 PM
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Car: `86 SS / `87 SS
Engine: L69 w/ TPI on top / 305 4bbl
Transmission: `95 T56 \ `88 200-4R
Re: Almost there... Idle question..

Does it warm up by driving it faster than it does just idling?
Idling is pointless when it comes to warming a car up.

Also, does it have a 195 t-stat? A new gasket and stat are cheap insurance.
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Old Nov 27, 2015 | 09:54 AM
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Car: 87 Monte Carlo SS
Engine: 89 350TPI Transplant
Transmission: 2004r
Axle/Gears: 3.73
Re: Almost there... Idle question..

Originally Posted by 86IROC112
I was thinking about buying this cable so I could do a full datalog on it? Thoughts?

http://www.moates.net/aldu1-and-cabl1-p-127.html
That's what I use to datalog with Tunerpro RT v5. Works good most of the time. Follow the instructions provided on the Moates website for setting it up.
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