soultcer
20.06.2021 18:09:20
Possible Fixes for Afterfire:
See full version: Why Does My Engine Backfire or Afterfire
Possible Fixes for Afterfire:
Possible Fixes for Backfiring: [links]
Backfire typically occurs when the engine is decelerated rapidly.
Common Causes of Backfire: [links]
Find out the most common causes and possible fixes for engine backfire and afterfire. more
Backfire is a condition described as a loud bang, poof, explosion, etc., while the engine is running or while shutting down. Afterfire occurs after the engine has been shut off. Note: Backfire and afterfire through the carburetor will not harm the engine at all!
Afterfire occurs after the engine has been shut off.
Common Causes of Afterfire:
The distributor/carburetor combination can make a difference, too. The 009 centrifugal-advance distributor was never intended to be used on road-going vehicles, and has to have a carburetor that is jetted a little richer, or you get "flat" spots (hesitation) on acceleration. The 30 and 31 series carburetors are not as bad for that as the larger 34, but this hesitation problem can still happen when these smaller carburetors are teamed up with the 009 distributor. These carburetors, especially the 34PICT, are much better suited for use with a vacuum-advance distributor, and especially with the single-vacuum dual-advance (SVDA) distributor, which combines the best of both worlds. here
Like the 30PICT series, the 31 series carburetor is actually a little small for the 1600cc engine (they have the same 24mm throat). That results in very high airflow speeds at higher rpm, and this can make the engine run a little lean too. Don't worry about the "little small for the 1600cc" comment though -- you lose only a few hp at the top end with this sized carburetor, and you actually get slightly greater torque at low/medium speeds. more
With regard to jet sizes: for a vacuum distributor, with a 30 or 31 series carburettor, try a size 55 idle, X125 or X127.5 main jet and a 125Z or 130Z air correction jet (try the first number first.) here
Yes indeed, what you are describing is backfiring. From what you say it sounds like a case of running lean -- backfires on overrun are very common with a lean-running VW engine. more
If I rev the engine while the car is stationary, and as the engine speed drops to normal, there's a loud bang or poot from the muffler, and sometimes fire comes out of the exhaust. This also happens when I coast down a hill and I'm in gear but I'm not pressing the accelerator, I hear the same poots and bangs from the rear. Is this what they call backfire? more
One may also ask, does backfire damage engine? An engine backfire occurs whenever the air-fuel mixture in your car combusts somewhere outside the engine's cylinders. This can cause damage to your car's exhaust or intake if left unchecked -- and it also means that your car's engine isn't making as much power as it should, and is wasting lots of fuel. more
What does it mean when your car backfires?
Shutting off the engine at high RPM, causing fuel to pump through the engine for ignition. Gasoline that contains alcohol has a tendency to ignite easier, which can cause afterfire. Small engine muffler type and manufacture. Carburetor adjustment may not be properly set for correct engine performance.
A spark plug that is damaged, worn, or has an improperly set gap between its electrodes creates a weak spark. As a result, the fuel may not ignite in the cylinder, but it might ignite when it reaches the hot exhaust muffler. The result is a loud backfire. Poor spark also results in a mower that runs unreliably. here
A bent push rod can also cause the valve not to work properly by restricting the movement of the valve. While the valve cover is still removed look at each of the pushrods to see if there is an obvious bend to them. This also can be done by detecting poor rocker arm movement while the engine is being cranked over. here
This condition may or may not be detected by the computer so the check engine warning light may not come on. Spark plugs should be changed at regular intervals, platinum plugs at about 60,000 miles which will correct this problem.
Anytime you have an engine that is backfiring the first thing to look for is a check engine light. If no warning lights are on continue down this guide. If the check engine or service engine soon light in on scan the computer for trouble codes. This will help locate the system that is having a problem and needs repair. [links]
Does your engine back fire and you are wondering why? We are a group of ASE certified mechanics that have created this guide to help you save money by fixing your car yourself or to see what you are paying for when taking it in for repairs.
We have had better luck by replacing the sensor because once this condition happens the hot wire can become unresponsive in which case the sensor needs to be replaced.