1991 Mercedes Benz 500sl Repair Question
Topics covered: Compression, Engine, Rpm.
Mileage: 85,000 miles.
Mileage: 85,000 miles.
Asked on September 2, 2011
How to find problem causing such high hc readings, cauling failure of emission testing
Idle is rough and at 2500 rpm engine has 900 ppm HC and you can hear and feel the miss. new pluges instaled.
Asked by captainkirkAnswer
Replied on September 2, 2011
You've pretty much answered your own question. HC is basically unburned fuel, usually caused by incomplete combustion and a misfire is exactly that. You need to locate and resolve the misfire issue. Look first at plugs, wires, injectors, etc.
Replied on September 2, 2011
Could be an ignition misfire, lean misfire and low compression
