Some common mechanical problems that cause misfire can be: If the ignition system and fuel system checks out, you may want to perform an engine compression test and leak down test to see if there are any mechanical problems causing your misfire.
Toyota rav4 2004 smokes on startup how to#
( How to check fuel injectors by ear, How to check fuel injectors with a digital multimeter ). Also, check that the fuel injector wiring is not damaged and is connected properly. Random misfires can be a sign of faulty or clogged fuel injectors that need to be replaced. Check that the fuel injectors are functioning properly and activating.
The fuel pump or fuel pressure regulator could be the source of the low fuel pressure. When the pressure is below the specification, the engine does not receive the proper amount of fuel and will start to lean misfire. Low fuel pressure can cause intermittent misfires on multiple cylinders. The following should be checked to ensure the engine is getting the proper amount of fuel: Check fuel pressure.
If you have determined that your ignition system is operating correctly, there may be a problem within your fuel system that is causing the random misfires.( How to identify a fouled spark plug, How to test spark plug wires, How to gap spark plugs, How to replace spark plugs, How to swap ignition coils ). Replace spark plugs and spark plug wires/ignition coil packs if needed and recheck for misfires. You can do the same test with the spark plug, i.e., move cylinder 4 plug to say cylinder 2 and if the misfire is now P0302 then the plugs are at fault. If the misfire moved to cylinder number 1 (P0301), then you have determined that the coil pack is faulty and needs replacement. If your vehicle is equipped with individual coil packs instead of spark plug wires, start by removing the cylinder 4 coil and swapping it with the cylinder number 1 coil. Check the condition of your spark plugs and spark plug wires.These can cause random misfire conditions. Look for loose engine ground wires as well.
Toyota rav4 2004 smokes on startup code#
Use FIXD to scan your vehicle to verify P0304 is the only code present.Tools You May Need (FIXD’s Top Picks From Amazon):ĭifficulty of Diagnosis and Repair – 2 out of 5.Loose fitting electrical connectors and broken or disconnected vacuum hoses are often overlooked. Ignoring this error could result in ignition failure, catalytic converter damage, and unsafe/dangerous conditions while operating the vehicle. Many times, P0304 occurs when there are worn out spark plugs, spark plug wires, or a faulty ignition coil. When P0304 occurs, it should be fixed immediately as long term driving with engine misfires could cause consequential damage to your engine. A misfire from one or more cylinders can be caused by many reasons from a faulty ignition system, fuel system, or internal engine failure. The efficient burning of fuel is essential to engine operation as the combustion of fuel is what provides the energy to power the engine. A misfire occurs when an insufficient amount of fuel is burning in a cylinder.
P0304 indicates that cylinder number 4 is experiencing misfires.