Hesitation Definition - An engine hesitation is an interruption of continuous power during acceleration. When a engine is hesitating it will cause the car to lunge or surge during acceleration which will cause a sudden jerk as the car slows down. This condition can cause dangerous situations in heavy traffic when drivers behind you expect you to move continuously forward. An engine hesitation can be difficult to detect because as the engine is running under power you have to decide if the engine is shutting off for a split second or if the engine is just losing power temporarily. 

If your engine stalls and then restarts please visit, why does my engine cut out. Please note that while an engine is hesitating it could cause damage to other components. Example: When an engine hesitates is will lose power then re-gain power quickly, this adds stress to the vehicles derive train and could cause premature failure. There are several systems are involved that can cause engine hesitation. We have listed some common reasons for engine hesitation

Car Repair Guide

Scan for Trouble Codes - Check to see if the "service engine soon" light is on, if not continue to the next step. If the "check engine" (same thing as a service engine soon light, different manufactures call it different things) light is illuminated you need to scanned for trouble codes. Use a simple scanner tool to retrieve trouble codes and check if they relate to the specific problem, like a fuel pump circuit failure code. If a trouble code is present but does not pertain to the immediate problem like an EVAP code ignore it until a later time, after the engine is running properly. The reason we repair non-related codes after the engine is running properly is because sometime false codes can be triggered by a poorly running engine.

Once the engine is running properly the code present might cycle and turn itself off. You might say "if the engine isn't running right shouldn't it have a check engine light and a trouble code?" Sometimes conditions occur that will not be detected by the computer, example: if the intake or exhaust valve operation fails the computer cannot detect the failure because the problem is not sensor related, so the engine has no power and the computer thinks everything is ok with no codes. If the trouble code retrieved relates to a low power like a mass air flow (MAF) sensor or ignition coil system failure repair these problems and re-test system. If no trouble codes are present proceed to the next step.

How to Scan for Trouble Codes Video

Check the Air Filter - A plugged air filter will not allow the proper amount of air into the engine. If air is not allowed to enter the engine's intake it will can cause the engine to hesitate. To check your engine air filter open the hood and remove the air filter from its housing and inspect, replace as needed and recheck.

How to Replace an Engine Air Filter Video

Check the Fuel Filter - Several conditions can cause engine hesitation, one of the most common reasons is a clogged fuel filter not allowing the proper amount of fuel pressure and volume into the fuel injection system.  To check for this condition remove the fuel filter and drain excess fuel from the filter, next wipe any excess fuel from the filter. By blowing through the filter you can determine if the filter is clogged, you should be able to blow through it very easily. If you cannot blow through it or it is difficult replace the fuel filter with a new unit and recheck system. Some fuel filters utilize a special release tool available at out tool store, if the fuel filter checks out ok proceed to the next step.