I have a 2000 Jeep grand Cherokee Laredo. When I start the car and let it idle it will seem like the vehicle shakes and wants to cut off and has even like it is not getting enough spark or power is my guess. But sometimes also if I go to. Drive the pressure or power when I push the gas pedal will not be there for a min and them all of a sudden it will just shoot in and the jeep. Will take off fast with a jerk. I thought maybe it's a tune up but not sure, can you help.
My car has 152 miles.
My car has an automatic transmission.
This may be a sign of a faulty MAP sensor as the vehicle responds adversely to a load put on the motor (i.e. putting it in gear, making turns (which makes use of the power steering pressure switch) turning on AC or engaging the brakes). The Manifold Absolute Pressure (MAP) sensor senses engine load and generates a signal that is proportional to the amount of vacuum in the intake manifold. The engine computer then uses this information to adjust ignition timing and fuel enrichment. When the engine is working hard, intake vacuum drops as the throttle opens wide. The engine takes in more air, which requires more fuel to keep the air/fuel ratio in balance. When the computer reads a heavy load signal from the MAP sensor, it adjusts the fuel mixture to slightly more rich than normal so the engine can produce more power. The computer will then retard (back off) ignition timing slightly to prevent detonation that can damage the engine and decrease performance. This may also be caused by other closely related components such as a dirty or failing mass air-flow sensor, a faulty throttle position sensor or potentially a vacuum leak. I would recommend having an expert from YourMechanic come to your location to diagnose and inspect your vehicle.
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