When your vehicle has low power output it can mean several different things are occurring. You should know while your car
has low performance it could be damaging components while you drive. Example: The emergency brake is on and you did not notice, this condition will burn up the rear brake pads or shoes and cause premature emergency brake failure. Or, the fuel filter is clogged causing thefuel pump
to labor which can cause premature fuel pump failure. There are basically two kinds of low power conditions either the engine is running rough causing low power or the engine is running smoothly but still has low power. If the engine is running smoothly but has low power you are in the right place.Step 1 - 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 manufacturers call it different things) light is illuminated you need to have the computer 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.Step 2
- Check the Air Filter
- A plugged air filter not allowing the proper amount of air into the engine. If air is not allowed to enter the engine's intake it will limit the engine power output. To check your engine air filter open the hood and remove the air filter
from its housing and inspect, replace as needed and recheck.
- Step 3 - Check the Fuel Filter - Several conditions can cause low power, 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 our tool store: Fuel filter release tool, if the fuel filter is ok proceed to the next step.
- Step 4 - Check Fuel Pump Pressure and Pressure Regulator - Fuel pump is worn providing low fuel pressure to the fuel injection system. A fuel pump that is faltering providing low system fuel pressure/volume will cause low power. Your car's engine depends on constant fuel under pressure to supply the fuel injection system properly. Your car's fuel pump performs this action and is located in or near the gas tank. The injection system meters fuel through the injectors and into the engine. Many engine run drivability problems can be related to a weak or failing fuel pump. Problems can range from hard starting in the morning, low power and stalling while driving. Most vehicles have a fuel pressure test port somewhere on the fuel rail, use a flashlight to locate it on your engine or consult a repair manual. Also test the fuel pressure regulator performance; if the regulator is stuck or leaking the engine will not receive the additional fuel needed for power. If the fuel system pressure is ok proceed to the next step.
- Step 5 - This step is for adjustable distributor type ignition systems only. If your car has a DIS (distributor-less ignition system) skip this step. Ignition timing is very important in achieving maximum power from your engine. If the timing is adjusted too far advanced or retarded (in front or behind the timing mark) in relationship to the engine crankshaft it will have low power output. To check your engines timing adjustment a timing light is needed. Once the timing light is hooked up to the battery locate the under hood emissions sticker that has the engine timing specification and instructions. If you can't find the under hood sticker or it is illegible consult a car repair manual. If the engine timing is ok proceed to the next step. If the engine timing is way off (20 degrees or more) check the timing belt or timing chain, the crankshaft camshaft correlation might be o