Poor Cold Idle -- Speed Density
Poor Cold Idle -- Speed Density
92 speed-density TPI 383, XFI 280. Fires right up cold but within 3 seconds the CE light flickers on and then goes out, no code set. Starts to run like poop and have to hold the pedal to keep it running for about a minute; then suddenly it will smooth out and settle into its normal lopey low-vacuum idle. Drives perfectly after that.
Any ideas?
Any ideas?
Joined: Nov 2008
Posts: 2,101
Likes: 180
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: Poor Cold Idle -- Speed Density
Is this a sudden problem or after you made changes? If you made changes, did you retune the ecm? Otherwise, test your CTS.
Re: Poor Cold Idle -- Speed Density
Done it since it was built. Tuner never had it to work on when it was cold; I drove it over there, cooled it down for a couple of hours, and then he tuned it. I did mention it at the time and he said he couldn't see anything related. Wasn't real gung-ho on tuning the factory setup though -- something a little different but no real groundshaker (he's used to tuning 1000hp turbo builds etc.) Said it was impressive for a TPI but that's about it . . .
What's a CTS?
What's a CTS?
Joined: Nov 2008
Posts: 2,101
Likes: 180
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: Poor Cold Idle -- Speed Density
A Caddilac.....I mean a coolant temperature sensor.
Joined: Dec 2004
Posts: 16,808
Likes: 1,008
From: Mile High Country !!!
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: Poor Cold Idle -- Speed Density
Sounds like you will need to buy a burner and adjust cold start enrichment yourself.
Joined: Nov 2008
Posts: 2,101
Likes: 180
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
CTS can be tested with an ohm meter, the table for what ohms at what temperature is on tgo, just search. Tuned even posted it before. I don't think that's your problem though.
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Joined: Dec 2004
Posts: 16,808
Likes: 1,008
From: Mile High Country !!!
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: Poor Cold Idle -- Speed Density

using tunerpro rt, it would be good to see the blm numbers in closed loop in the 800-1400 rpm range. once the fueling correction has been fine tuned with the ve adjustments then cold start enrichments can be done. If the idle is poor ofter 160F the ecm may not be going into closed loop fast enought due to the o2 sensor not getting hot enough to become active. A heated o2 may solve this, Just throwing out some suggestions
Joined: Dec 2004
Posts: 16,808
Likes: 1,008
From: Mile High Country !!!
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: Poor Cold Idle -- Speed Density
Those are stock numbers, you might want to highlight the whole table and use the subtract bar setting at the top enter 2 and execute. If you have trouble reading your file feel free to send me a pm I'll walk you through it.
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