Car backfires through the carburetor are sometimes caused by a lean air/fuel mixture. Backfires may also be caused by a leaking hose, faulty plugs or the brand of fuel being pumped in. Backfiring is a loud bang or explosive sound that occurs while the engine is idling down or shortly after the engine has been shut off.
The factory Evolution engine's ignition can contribute backfiring through the carburetor. Cam design: Long duration cams with early opening intake valves can contribute to backfiring. Intake manifold air leak: A lean condition due to an intake manifold air leak can cause backfiring.
Small Engine; UTV Free shipping on orders over $100 ... Troubleshooting - backfire through carburetor . By: Bill Tichenor | 12/02/2009 < Back to Motor Life Home. Footage taken from Holley Carburetor Installation & Tuning DVD. Tags: Carburetor Installation and Tuning, Video, carburetor tuning and adjustments. Related Articles.
OK, so having a bear trying to get the SBC running smooth. Thought I had it, but alas seems to change its mind if I look at it funny. Now getting a backfire through the carb (seems to always be the one over the 5/7 cylinders) on acceleration. SBC 283 with 4 Holley 94. All recently rebuilt. 1 turn out on all 4 seems to give the best response.
It backfires when I start, then runs OK. What could be causing my engine to backfire? Answer: Check timing; check for a possible gasket leak, carburetor, and/or intake; make sure the choke is properly adjusted. Question: I have a 2003 Chevy Venture that backfires through the air filter housing on acceleration. What is the problem?
First and the most common way is when the engine is running a small explosion of un-burnt fuel is ignited inside of the intake manifold creating a loud bang which is the backfire sound you hear. This explosion can bend the throttle actuator plate, push intake gaskets outward creating a vacuum leak and even blown apart a plastic intake manifold.
No more backfiring, no engine run-on , but I still have a little a slight stumble under hard acceleration. My next step will be rebuild the carb and start trying set it up correctly. I may need to put a smaller power valve, I have around 10 inches of vacuum at idle and I a have a #65 valve in this setup.
Backfires only when loaded: Loose-fitting valves, spark plug wiring issues, leaks in carburetor diaphragm. Backfires on idle : Too lean of an air/fuel ratio (in a propane engine), loosely connected or malfunctioning alternator, or bad connections on your caps and rotors.
Next I'd have a look at the carburetor, take off the bowl and see if its all gummed up with crud, if so clean it. If its still giving trouble, you might need to give the carb a good cleaning, which mostly sucks so because I'm lazy I'd try to run some barryman's b12 through it and see if that fixes it first.
Quite often, these springs get lost, etc when the carb or cables are adjusted/serviced, and running without it is a common cause of backfiring. The spring goes between the "arm" on the carb and the cable stop that is used to adjust the throttle.