Failed Air Intake Boot
How to Replace an Air Intake BootStep 5 - Check for Plugged Exhaust System: The exhaust system in your vehicle is designed to release exhaust gases from the engine to the rear of the car. This system is designed to have about 3 pounds of exhaust backpressure under full throttle. This means the engine should not have to push more than 3 pounds of pressure to release the exhaust at any given time. If a catalytic converter plugs or breaks apart it will plug the exhaust system causing an engine surge.
Plugged Catalytic ConverterStep 6 - Test for Weak Ignition Spark or Failing System: A weak ignition system can be a sign of a failing ignition component and can cause the engine to surge. Remove spark plug wire and insert an extra spark plug into end of wire, attach spark plug to engine ground then crank engine. You should observe blue spark between spark plug gap. If a yellow spark is observed, your ignition coil is weak and needs to be replaced. Also the spark should flash in a constant rhythm, if the spark is inconsistent suspect the crank angle senor, ignition coil or ignition module.
Testing an Ignition System VideoStep 7 - Check for Automatic Transmission Clutch Slippage: When the clutches inside an automatic transmission start to wear they can malfunction. This condition will deliver a surging or a tugging sensation to the driver. Without taking the transmission apart it is impossible to check the wear of the clutch discs. But there are tests that can help you in the diagnosis. First remove transmission dip stick and inspect the condition of the fluid; if the fluid has a burnt smell and is dark color instead of the normal red color the fluid is burnt. (The transmission fluid is a hydraulic fluid that when extreme heat is applied to the fluid it becomes dark in color and will smell burnt). The extreme heat is generated from the clutch discs slipping. Sometimes a transmission service will help the operation by removing the burnt fluid and replacing it with new.