high exhaust emissions, when idling |
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high exhaust emissions, when idling |
DavidSweden |
Jul 10 2019, 02:32 PM
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#1
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Member Group: Members Posts: 479 Joined: 8-June 14 From: Sweden Member No.: 17,452 Region Association: Scandinavia |
76- 2.0- D jet with Pertronix ignition
Car has high emissions at idle but good at higher rpm. Engine warm Does this indicate that the engine is miss firing one one cylinder when idling and how do I check that its firing on all cylinders? The engine sounds fine, any ideas as to what is causing the high exhaust emissions? |
jcd914 |
Jul 10 2019, 05:31 PM
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#2
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Advanced Member Group: Members Posts: 2,081 Joined: 7-February 08 From: Sacramento, CA Member No.: 8,684 Region Association: Northern California |
What emissions are high? CO% HC ppm? Other?
A vacuum leak could create a lean miss at idle that goes away at higher RPM. Overly rich idle mixture could lean out at higher RPM. Jim |
Bleyseng |
Jul 10 2019, 08:38 PM
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#3
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Aircooled Baby! Group: Members Posts: 13,034 Joined: 27-December 02 From: Seattle, Washington (for now) Member No.: 24 Region Association: Pacific Northwest |
Overly rich? Could be the CHT is going......
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DavidSweden |
Jul 11 2019, 10:02 AM
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#4
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Member Group: Members Posts: 479 Joined: 8-June 14 From: Sweden Member No.: 17,452 Region Association: Scandinavia |
What emissions are high? CO% HC ppm? Other? A vacuum leak could create a lean miss at idle that goes away at higher RPM. Overly rich idle mixture could lean out at higher RPM. Jim High HC ppm, the idle is about 700 It sound like its firing on all cylinders, I will check the hoses any other ideas? |
Dave_Darling |
Jul 11 2019, 05:00 PM
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#5
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914 Idiot Group: Members Posts: 14,974 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California |
Turn the idle RPM up to at least 900. We usually run it "just under 1000". I think the factory spec is somewhere between 800 and 950 RPM, depending on the exact year/engine.
Try adjusting the knob on the ECU. Count the number of "clicks" on the knob, or mark it so you can get it back to where it was if you need to. Going counter-clockwise should make the mixture leaner at idle only. If that helps your CO, then you were running rich. If that doesn't help, try going the other way. --DD |
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