Why does my Chevy 350 backfire when I let off the gas?

Why does my Chevy 350 backfire when I let off the gas?

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. The air injection check valves (STANDARD MOTOR PRODUCTS PT#AV7) are common failure parts.

What causes an exhaust tail pipe to backfire?

An exhaust tail pipe backfire is caused by an excessive amount of un-burnt fuel remaining in the exhaust system or fresh air being allowed to enter the system which ignites a small amount of un-burnt fuel. If fresh air is allowed to leak into the exhaust system it will ignite the un-burnt fuel inside the system creating a popping noise.

What causes a car engine to make a sputtering noise?

The car has a set of vacuum hoses that, with time, develop leaks. This will cause the engine to produce a sputtering sound when the air-fuel mixture gets too rich or too lean. 4. Dirty mass airflow sensor The combustion chamber requires the right amount of fuel and air.

Can a bad throttle position sensor cause idle surging?

Idle surging can be caused due to other issues in the car, but if it happens in conjunction with other throttle position sensor symptoms, the culprit is often the TPS. At idle, the ECM will not get the correct information and the throttle will variate randomly causing idle surges. 3) Check Engine Light

An exhaust tail pipe backfire is caused by an excessive amount of un-burnt fuel remaining in the exhaust system or fresh air being allowed to enter the system which ignites a small amount of un-burnt fuel. If fresh air is allowed to leak into the exhaust system it will ignite the un-burnt fuel inside the system creating a popping noise.

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. The air injection check valves (STANDARD MOTOR PRODUCTS PT#AV7) are common failure parts.

The car has a set of vacuum hoses that, with time, develop leaks. This will cause the engine to produce a sputtering sound when the air-fuel mixture gets too rich or too lean. 4. Dirty mass airflow sensor The combustion chamber requires the right amount of fuel and air.

What should the TPI be on a street engine?

On a street engine, try to stay under 200cc. Here are the stock TPI head flow numbers along with some other popular GM heads. 416 305 heads Lift/intake/ exhaust. 0.050 31 15 0.100 63 37 0.150 92 61 0