Hesitation is a momentary loss of power during acceleration.
- A vehicle may cause car hesitation or a sluggish condition for some reason; The fuel system could be feeding an excessively rich or an excessively lean mixture. A lean mixture could be due to a defective fuel pump, clogged fuel line, filter, and air leaks into the intake manifold. A rich mixture could be due to worn carburetor jets or leaking fuel injectors.
- A faulty accelerator pump or power system may be the cause of lack of power for the vehicle you may also check if the engine hesitates or stumbles when the accelerator pedal is depressed, and then runs normally. This indicates the trouble probably is in the accelerator pump. Check pump operation by shutting off the engine and removing air cleaner. Then operating the throttle linkage to open the throttle valve and observed for a fuel discharge
- The engine could be overheating due to a carburetor choke that may not be working. This feeds the engine an excessively rich mixture that burns poorly causing poor performance. A stuck manifold heat control valve overheats the mixture so less goes into the engine cylinder, Vapor lock may also cause poor engine performance and hesitation