If you have not changed the fuel filter lately locate and replace it When they plug due to particles in the gasoline they can case a lean condition. Some cars have a fuel filter which can also cause a fuel pressure and volume restriction. The fuel system pressure must be tested to see if the fuel delivery system is the problem. The most common cause for this problem is a weak fuel pump which cannot supply the volume of fuel needed for the injectors to produce a proper spray pattern or deliver the amount of fuel needed for engine acceleration. Proper fuel pressure is needed to atomize the fuel correctly when it leaves the fuel injector to complete the burn process. Every internal combustion engine runs on a mixture of 14 to 1 which is fourteen parts air to one part fuel. This will help locate the system that is having a problem and needs repair.Īn intake back-fire explosion can be caused by the fuel air mixture being to lean when the engine is demanding power. If the check engine or service engine soon light in on scan the computer for trouble codes. If no warning lights are on continue down this guide. If the POP is from the intake you have to check all the vacuum hose connections and the throttle body base gasket because the POP will blow the hoses off and can blow a section out of the base gasket causing an even leaner fuel mixture.Īnytime you have an engine that is backfiring the first thing to look for is a check engine light. The hose is available in the "HELP" section at any Auto Parts store. Most of the time the engine will idle at a higher RPM a suction sound can be heard. The 90 degree elbow in the PCV Valve hose at the base of the throttle body to the PCV valve is common to either fall off or have a hole in it. If you hear a pop sound under the hood when you accelerate it is most likely running lean (Not enough fuel) from either a vacuum leak or the fuel pump failing (low fuel pressure). Be sure to use a wrench on the pipe and a wrench on the valve or the pipe will twist and break and sometimes a torch is required. Cost about $18.00 each you should replace both if they are the problem. The air injection check valves (STANDARD MOTOR PRODUCTS PT#AV7) are common failure parts.
#How to install spark plugs with headers on a 350 cracked
If it backfires when you let off the gas peddle it has air getting into the exhaust, either an exhaust gasket or cracked manifold before the catalytic converter or the emission control's Air Injection system.