Backfiring, stuttering, no acceleration
Supporter
Joined: Jan 2007
Posts: 15,787
Likes: 5,612
From: along the shore of Mishigami
Did you put any fuel stabilizer in the fuel prior to letting it sit. Fired up two of mine the other day when it was warm out and they fired right up. Today's gas is crap, and ethanol phase separation is common when moisture is introduced to fuel tanks (think condensation). Get of the old gas, put in fresh gas with Sea Foam mixed in. Do this with a couple of tanks. I've got a feeling the injectors are varnished or gummed up.
1st Gear
Joined: Mar 2018
Posts: 5
Likes: 0
From: Texas
As Jay Guild mentioned it could very well be the TPM. Most if not all fuel injected vehicles experience wear and tear on the TPM, and if left unchecked, will cause the vehicle to experience the symptoms that you have mentioned (a dip in gas efficiency is another one).
It's a pretty cheap DIY fix.
Check this article out for reference:
https://thebikersgarage.wordpress.co...-a-motorcycle/
It's a pretty cheap DIY fix.
Check this article out for reference:
https://thebikersgarage.wordpress.co...-a-motorcycle/
Thread Starter
|
Intermediate
Joined: Mar 2018
Posts: 31
Likes: 1
From: Arkansas
As Jay Guild mentioned it could very well be the TPM. Most if not all fuel injected vehicles experience wear and tear on the TPM, and if left unchecked, will cause the vehicle to experience the symptoms that you have mentioned (a dip in gas efficiency is another one).
It's a pretty cheap DIY fix.
Check this article out for reference:
https://thebikersgarage.wordpress.co...-a-motorcycle/
It's a pretty cheap DIY fix.
Check this article out for reference:
https://thebikersgarage.wordpress.co...-a-motorcycle/
Well I changed the plugs and drained the fuel and put more in with some fuel injector cleaner added. Still doing the same thing. Idles fine but any throttle and it begins to bog down, wants to stall and backfires. I actually had to buy a TPS just for the screws, so I guess I can swap that out and see what it does. I'm at a loss otherwise.
Thanks for all the suggestions.
Grand HDF Member
Joined: Jun 2013
Posts: 4,998
Likes: 864
From: Iowa
When my TPS went bad I would be riding and the bike would start coughing and backfiring, and then I would have no throttle response until I twisted it hard and then it would act OK for a few minutes but then keep doing it. Hooked up the SERT and sure enough the TPS was reading 18% high at every position so I was flooding the engine without the intake valve open enough. This will give you a MAP sensor error as well because the pressure is not high enough for the air/fuel mixture that is too rich. If you don't have an interface to read the throttle position from the ECM:
Thread Starter
|
Intermediate
Joined: Mar 2018
Posts: 31
Likes: 1
From: Arkansas
I also just remembered I have a V&H FP3 installed. I've actually never used the app until today. Is there anything I can glean from the app which would help me troubleshoot, other than codes?
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Southpaw Super Glide: A Left-Hand-Drive 1979 Harley FXE Built to Fit the Rider
Verdad Gallardo
Grand HDF Member
Joined: Jun 2013
Posts: 4,998
Likes: 864
From: Iowa
Hell's yeah. When you get in to the app with the bike on and you are connected with the bluetooth there is a View Sensor Data button. Go in to that and in one of the corner circles there is a TPS position reading. It should be at 0 with a proper TPS. If it doesn't say TPS in any circle then you need to select one of the circles in the corners and change it to the TPS reading. Adding a reading as high as 5% is acceptable though.
Last edited by Jay Guild; Mar 22, 2018 at 04:37 PM.