When a vehicle has sluggish acceleration, it can be quite irritating. Even more concerning, it can be life threatening.
Making sure your vehicles performance is up to par is crucial, especially when getting on the main interstate.
If a fuel pump is not performing to manufacture specs, it will cause your acceleration to plummet. Hesitation,sputtering & misfiring, all can be signs your fuel pump is going out. One way to be sure it's your fuel pump, or fuel pressure regulator, is by testing the fuel pressure at either the fuel rail, or fuel filter.
A clogged fuel filter is guaranteed to slow your acceleration down, and could even cause idle problems as well. The price of fuel filters are reasonably priced at any local auto parts store. It's best to just replace it at 50,000 miles.
Fuel injectors spray fuel, but they also regulate how much is added to the combustion chamber, increasing power or decreasing. Fuel injectors have small built in removable filters inside the tip on the injector, you can see these when you pull the injector out of the fuel rail, "they are removable and replaceable." You can purchase injector cleaning solution that you simply pour in your gas tank at fill up at any local auto parts store. Fuel injectors can be bench tested and clean by a injector cleaning shop, in some cases it's best to replace the entire injector if it's a electrical impedance issue.
Catalytic Converters filter pollution from gases created by the engine with thousands of tiny holes that the exhaust flows through. The catalytic converter burns the gases before they exit the exhaust and into the atmosphere. Catalytic Converters are made up of a ceramic or metallic substrate, coated by an aluminum oxide and platinum. If your vehicle has an abrupt back fire, it can damage the catalytic converter causing poor acceleration and poor mpg. If at any point your vehicle had a blown head gasket, and the poor acceleration has come after the repair, the catalytic converter could be coated with either anti freeze, or burnt oil and will need to be replaced.
Spark Plugs & Plug Wires
Fouled spark plugs and shorted plug wires can cause poor acceleration, misfire and hesitation. Replacing them can put your vehicle back to it's original performance level. Rule of thumb is to replace spark plugs and plug wires every 30,000 miles.
Distributor Cap, Rotor & Coil packs
Any time you change your spark plugs & wires you should change the cap and rotor as well, doing so can avoid the hassle of troubleshooting another misfire or skipping issue. Coil packs tend to just completely cut out, if your vehicle sounds like a 3cyl when it's a 4cyl, simply unplug and plug each plug wire while the vehicle is running, the one that doesn't change the engine tune is most likely shot. Make sure you're using a known good plug & wire or you could throw away a good coil pack accidentally.
In some cases, simply changing that old air filter will do the trick. A dirty air filter can kill gas mileage, performance & drive ability. Rule of thumb is to replace the air filter every 45,000 miles.
IACV (Idle Air Control Valve)
A clogged IACV can cause low idle and stalling when the A/C kick's on. The reason this happens is the a/c put's a load on the engine, and when that happens, the IACV is suppose to increase the rpm. If it's clogged that won't happen, and your vehicle will sputter, and can even stall. Clean the IACV can bring your idle back to life. IACV can prevent off the line acceleration also.
Tps (Throttle Positioning Sensor)
A TPS controls your acceleration by sending voltage signals to the ECU, then the ECU sends it to the injectors. If your experiencing acceleration or hesitation while increasing the throttle at any point, it could be the "TPS". A simple multi meter voltage test can rule out if that's problem or not.