Sbc backfire on deceleration. Oct 12, 2008 · Not sure about the popping.
Sbc backfire on deceleration The bike has a JD jetting fuel injection tuner on it. It idles smoothly and revs fine in park. It worked. This can happen if the mixture is too lean or if there is an ignition timing issue. No popping or backfire on acceleration or deceleration. There's other possibilities too but an ignition source is getting into the intake tract. I then turned the secondary idle screws out 1/4 turn on all 4 and then decided to increase timing to 18*. This is a recent occurrence, and not associated with any engine work. It can also be dangerous if it happens while the vehicle is being driven. The bike has been backfiring on deceleration from the start, typically on heavy deceleration. I have 100 miles on the car, I have the "mild" cam setting loaded and the only changes I have made to my setup are the base timing and getting the IAC % down when engine is warmed up. Not all the reasons, but the biggest ones. Backfire can damage the engine and cause it to lose power. Jul 30, 2022 · I can't figure out what's happening with my sbc 350. 5 about 4 years old. The carburetor delivers the air/fuel mixture to the engine, and the distributor ignites that mixture within the cylinders. There is no popping in at wide open throttle. 7/4L80E 4x4 2015 GMC Sierra SLE 1500 4x4 09-09-2009, 09:33 AM Aug 2, 2009 · ok half of the wires are lightly touching the headers. Other Oct 10, 2004 · Ok, i have completely new valve train, ignition, and carboration/intake systems on my 1974 454 chevy big block. so I can be at 55 within a few seconds. Most owners seem to like the popping (kinda like most Harley owners like the loudest straight pipes possible), but you can't please everybody. If its backfiring thru the carb, its a good bet that its sparking with an intake valve open. Extremely strong acceleration. Nov 23, 2022 · Backfire in the carburetor is a condition that occurs when the air-fuel mixture in the engine combusts outside of the engine. It can also be caused by mal adjusted carburetor. Nov 3, 2009 · I am slowly working the bugs out of a new cam and head swap. May 18, 2019 · Backfire during deceleration is often caused by excess fuel in the cylinder. Jun 3, 2013 · The air management system (smog pump and diverter valve) controls air injection into the exhaust stream, whereas the deceleration control leans the intake mixture to compensate for the richer fuel mixture during deceleration. Jul 31, 2022 · I'm getting the normal exhaust backlash I'd expect from short pipes but my driver side has a loud backfire out of the exhaust when I let the throttle snap shut to shift. I am having problems with the motor popping through the exhaust. The popping is not caused by an external leak but by air and fuel not completely shut off. from there we pulled the intake off to check all solid roller lifters where they were all fine,adjust all the rockers over sealed intake and adjusted timing over again changed all componets that is in or around an MSD distributer Ignition Timing: Incorrect ignition timing can contribute to backfiring. If I keep the throttle from completely closing all the way it doesn't do it. Apr 15, 2019 · Three main causes for backfiring on a distributor engine. Dec 29, 2005 · I have a 1992 K2500 with a completely stock tbi 350 with 160,000 miles on it and am getting a backfire through the exhaust when decelerating. This excess fuel then gets pushed out and enters the hot exhaust system, where it ignites and causes a backfire. May 6, 2006 · Sometimes popping on decel is caused from an exhaust leak. Faulty Fuel Injection System. Seems to be mostly on the left bank. im not sure if its 1357, or 2468, but half are positively touching, i pulled them off my small block, and they are msd 8. The timing is 38 degrees. Something you should understand before going any further is that a motor in perfect tune will exhibit deceleration backfiring. May 14, 2022 · Backfire through the exhaust during deceleration can be quite a perplexing issue for many car enthusiasts and everyday drivers alike. . The harder the decel, the more it will backfire; the more unburned hydrocarbons that collect in the exhaust, the more it will happen. Oct 12, 2008 · Not sure about the popping. Let’s delve into the potential causes and offer some insights on how to troubleshoot this issue. But for the poor acceleration, it could be running out of fuel. 30 over) Iron vortec heads Lunati cam 489/504 lift, 227/233 duration @50 10:1 compression 3. It has ported 882 heads that are freshly decked with new valve guides, valves and springs, new cam and lifters and new intake with a Holley 675 carb. 73 posi rear end Exhaust backfire on deceleration Aug 30, 2020 · Backfire on deceleration Jump to Latest 3. Understanding these causes is crucial in diagnosing and resolving backfire issues effectively. Any help on why it pops will be appreciated. -timing is 18btc(doesnt improve when altered)-dwell is 31-ive sprayed carb cleaner around possible vac leaks (no dice)-no exhaust leak Aug 6, 2010 · I have strong, smooth acceleration under load, and smooth no-load deceleration (clutch in, load off engine - decelerates quietly and smoothly). Apr 14, 2021 · Dart 427 with Pro Flo 4, engine seems to be running great but I am getting popping out exhaust on deceleration (downshifting). It runs fine when cold but once the engine gets up to operating temperature, it backfires whenever I lift my foot off the gas and don't push in the cluch. 2K views 7 replies 4 participants last post by Santacarl Sep 1, 2020 Jul 27, 2014 · Ive searched for answers and have checked everything ive read. the 65 is just a speed I tested with to see what would happen. Much improved. It has PLENTY of power and torque in my 81 camino, but when i'm coming down from a high revolutions it wants to backfire through the exhaust it does it when i'm coming down an off ramps from the hwy. Proper carb adjustment and tight exhaust joints is the best you can do to minimize it. No change. Vacuum Leaks: Vacuum leaks in the intake system can also affect the air-fuel mixture, leading to improper combustion and backfiring Sep 29, 2009 · Exhaust backfire on deceleration Engine & Drivetrain 1999 Chevy 2500 OBS, Longbed 5. Thanks Feb 16, 2013 · Deceleration backfire is caused by fuel burning in the exhaust manifold or header. The former is normal and harmless (and either sounds awesome or annoying, depending on your personal preferences), while the latter probably means there’s something wrong with your motorcycle. If you want to get rid of the noise, you will need to de Dec 16, 2017 · At the end of the day, some backfiring on deceleration is going to happen, it's just a matter of how much. both on the "factory" and recommended" setting the bike still backfires. If the timing is too advanced during deceleration, it can cause the air-fuel mixture to ignite at the wrong time, leading to backfire. Sep 8, 2014 · Bumping your initial 2* is probably not helping your backfire. :turn: Jul 12, 2014 · It helped but I still had some backfire. Intake is a 3x2 setup with 2G's. Oct 17, 2024 · Backfires can be caused by various factors such as timing issues, fuel system malfunctions, or exhaust leaks. When you decelerate, the intake valve closes sooner, which might leave some unburnt fuel in the cylinder. The motor only does it when it is idling for alittle while or really slow speeds. Mar 17, 2011 · New designs starting with the 2008 NPP keep the valves open during decel to make more noise. A fault in either system can cause annoying backfire on deceleration. It could be extremely lean too. Apr 18, 2023 · Exhaust pops during decel and big-bang backfires. I Backed off timing to 14* initial. Under load it backfires through the intake. However, if I downshift and decelerate under load (engine braking), I get all kinds of popping and backfiring through the exhaust. A faulty fuel Chevy 355 (350 bored . I cant seem to get rid of the popping out the exhaust on deceleration. Deceleration Backfire Explained. Engine is the GM 350/357 crate with 100 miles on it. "How do you get up to 65 mph before the engine warms up? " I live on a county road. This phenomenon is not only annoying but can also indicate underlying problems that might need addressing. May 16, 2009 · Lot's of popping and cracking on deceleration The 1967 - 1972 Chevrolet & GMC Pickups Message Board 1970 Chevy C20 daily driver 1975 GMC Jimmy 4x4 project Oct 12, 2008 · I have an sbc that was broke in on the dyno about 2weeks later here comes this poppin/backfire out the exhaust i took the whole car back to shop that build the motor. Jul 4, 2010 · backfire on deceleration Jump to Latest Follow 4K views 8 replies 8 participants last post by the FLYER Jul 6, 2010 Feb 4, 2022 · Hey guys! Not too long ago i picked up a 2013 Ktm 350 exc-f, keep in mind the bike only has 1,200kms on it (750miles). Common Causes of Backfire During Deceleration Fuel On a hard deceleration, it is normal for a few backfires to pop out the exhaust. Thankfully, because both of these components are on top of Chevrolet's 350 small-block engine, checking them is quite easy. Just because your exhaust is popping, doesn’t mean there’s anything wrong. I would first try re-tightening all the exhaust manifold bolts. However, if you feel it is excessive - your timing chain might be stretched and the slop in the chain changes the cam timing, which causes the cam to be out of time with the rotating assembly - which can cause excessive backfiring. On a hard deceleration, it is normal for a few backfires to pop out the exhaust. Spark is occurring when an intake valve is open. Deceleration backfire specifically happens when the throttle is closed, and the engine transitions from a The problem can usually be traced to the carburetor or distributor. What pump are you running? what size fuel line? Aug 30, 2020 · Back fires are caused by timing or valve train problems. Maybe worse. ytmlr prak iyqhkfmv ywycor vad cros bqcs nsv owlb uxcyhi