96 Pickup Problems

[mike4570]

Help! My 96 pickup with the 2.4l engine keeps running rich.I cleaned the MAFP (mass air flow sensor), replaced the throttle position sensor, and replaced the rear O2 sensor. When it's cold the engine seems to run fine, but when it warms up it starts to run rough, spews black, sooty smoke. Idle speed drops to the 500 rpm range and the engine dies.Several years ago the MAFS was replaced, vacumn hoses replaced, loose intake manifold bolts tightned.Any help or advice is greatly appreciated.Thanks, Mike

[Desert Rat]

sounds like a bad vacuum leak to me. Get a can of carb cleaner and spray around the engine's vacuum fitting when it's running....if the idle changes, you found a leak.

[mike4570]

Thanks for the tip on the vacumn leak. I wish that was the problem. I finally got the truck to show a trouble code. P0100, Mass or Volume Air Flow Circuit malfunction. Anyone have a source for these? My parts guy says these are dealer only and come with the throttle body as a complete assembly. He says his cost is about $450.00! Any advise would help.Thanks, Mike

[Big-Bird]

You could try removing the MAFS and spray it with electrical contact cleaner. This can sometimes blast the oily dust that gets stuck to the wire in the sensor and that oily dust can cause some runability issues. Worked on my 2000 Xterra and saved over 4-BILLS in the process.

[NM50]

Sometimes the harness around the air filter housing rubs through and the harness breaks where it goes behind the engine hanger and up to the firewall.

[cardude123]

Auto Mammoth carries these parts at a very reasonable price. You need the part AFH55m-12 mass air flow sensor. They offer free shipping and a 5 year warranty. $79 sure beats $400