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2015 Stock Viper backfires occasionally on deceleration

SeX Viper said:
I rode Friday night about 30 miles and no issues. I rode all day Saturday 175 miles and no issues until the end of the day and it stared again, the temp was only 10 F at that point so my theory about air temp is out the window. We rode again on Sunday and no issues. I like this theory about the valves needing adjustment but wouldn't think it would be intermittent if that was the case.
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Just thought I'd give an update. I'm pretty sure I resolved my backfire issue. My last resort was to install a PCV fuel programmer and slightly increase the fuel percentage at idle and slightly off of throttle from 1250 rpm through 3750 rpm that I read from another older thread. Well, so far it worked!!! I have to take it on a longer ride yet but so far no backfires!
 

So even with the '19 flash they still haven't got the fuel mapping figured out?
 
pdiddy said:
So even with the '19 flash they still haven't got the fuel mapping figured out?
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Not many others seem to have the issue with the latest flash, but for some reason mine still had that lean/pop issue at zero throttle letting off the gas. It was driving me nuts! At least I finally figured it out. Hopefully be able to enjoy it for the rest of the season...
 
I hope you're good to go now! The only other thing I can think of that hasn't come up in this thread but has in others is the crank position sensor. Issues are mostly related to hard starting.
 
Hibb Viper said:
2015 LTX all stock backfires or pops on deceleration when coming to a stop and letting off the throttle, but works great besides this issue. If I ease off the throttle it doesn't backfire. Has new gas and spark plugs. New ecu in 2019 with newest flash at the time (previous owner). No cracks in header pipe. Stock muffler isn't blown out and gasket is good yet. Any ideas of what to try next? Do I need a PCV to mess with fuel settings at lower rpms? Is this just the nature of the beast? Let me know what you guys think. Thanks!!
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I had cold start issues and had to crack the throttle to keep it running until it warmed up ( 75 degrees) on my 2017 Viper. After running the trails I had a hard time starting it after we stopped for lunch. Took it to the dealer and they played with the TORS and finally disconnected it...made no difference. To make a long story short I took it to an awesome mechanic to get the valves checked. I have 11,500 kms on it and 4 valves needed to be replaced and the other 2 adjusted. Hopefully this helps anyone with same issues.
 
Cally Kid said:
I had cold start issues and had to crack the throttle to keep it running until it warmed up ( 75 degrees) on my 2017 Viper. After running the trails I had a hard time starting it after we stopped for lunch. Took it to the dealer and they played with the TORS and finally disconnected it...made no difference. To make a long story short I took it to an awesome mechanic to get the valves checked. I have 11,500 kms on it and 4 valves needed to be replaced and the other 2 adjusted. Hopefully this helps anyone with same issues.
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My valves were out of spec and thought that was going to fix my issue by shimming them back into spec, but unfortunately didn't. For me it was just a little lean just off the throttle towards idle. Getting a fuel programmer and tweaking the fuel at low rpms at idle and just after idle resolved my issue and ran perfect for the rest of the season.

Good info on what fixed your issues though. I had a Kawasaki ATV that the valves kept going out of spec and behaved exactly like you stated.
 
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