guitarplayinman

I have a 2000 Frontier 4X4 3.3L King Cab. Just recently it has started to black smoke when it first starts up, and about 30 seconds to a min. after I start driving. I have tried to trace the problem with no luck, all I can tell is that it is running really rich, hense the black smoke. The truck does not miss or does it have any other mechanical flaw that I can tell. Also, the Check Engine Light is not on and I am really not sure where to go from here.
Any help would be appreciated.

boogyman

Usually black smoke when you first start up is the valve seals. That seems kind of unusual on a newer car. How many miles do you have?

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'05 Pathfinder LE
'03 Saab 93SS

smj999smj

Blue smoke when you first start is valve seals...Black smoke indicates unburned fuel. First thing I would look at is the vacuum hose to the fuel pressure regulator at the back of the engine; I've seen a few become disconnected and cause an overrich condition on these engines. Second, I would get a fuel pressure gauge and test the fuel pressure, the pressure regulator, and check the fuel pressure leakdown (for a possible leaking injector). A dirty MAS hotwire could throw the readings off, so you may want to carefully clean it with MAS cleaner or electrical contact cleaner; this I would seriously consider if an aftermarket, oil coated, air filter is used, ie K&N. Make sure you have the proper type, NGK spark plugs installed and the secondary ignition is in good shape. After that, it would be best to use a scantool to monitor the datastream of the ECM, especially concentrating on what the O2 sensors are reading.