Help - Search - Members - Calendar
Full Version: high exhaust emissions
914World.com > The 914 Forums > 914World Garage
DavidSweden
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
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
Overly rich? Could be the CHT is going......
DavidSweden
QUOTE(jcd914 @ Jul 10 2019, 03:31 PM) *

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
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
This is a "lo-fi" version of our main content. To view the full version with more information, formatting and images, please click here.
Invision Power Board © 2001-2019 Invision Power Services, Inc.