Rough running
Road Captain
Joined: Feb 2006
Posts: 521
Likes: 3
From: Virginia
RE: Rough running
FI Idle fluctuations
If the hot idle speed on EFI models falls below preset values, you should check for low fuel pressure.
Low fuel pressure could be caused by a hole in fuel hose inside the tank. If fuel pressure is low, it
may require removal and inspection of fuel feed hose from pump to filter.
If the hot idle speed fluctuates or increases while running, you may have a problem with the engine
temperature circuit. This problem can cause high idle, rough running, and black smoke coming from
exhaust. You can verify this problem by monitoring scanalizer readings when the problem occurs.
Normal reading should be >284âF. If readings are observed to be lower, then diagnostics are
required. Most of the time this condition will not register a trouble code. You should perform a thorough wiggle test on ETS circuit as described in Service Manual. Connections have been found to
be the problem in most instances. If no problems are found with wiring or connections, then a new
sensor may be necessary.
If the hot idle speed on EFI models falls below preset values, you should check for low fuel pressure.
Low fuel pressure could be caused by a hole in fuel hose inside the tank. If fuel pressure is low, it
may require removal and inspection of fuel feed hose from pump to filter.
If the hot idle speed fluctuates or increases while running, you may have a problem with the engine
temperature circuit. This problem can cause high idle, rough running, and black smoke coming from
exhaust. You can verify this problem by monitoring scanalizer readings when the problem occurs.
Normal reading should be >284âF. If readings are observed to be lower, then diagnostics are
required. Most of the time this condition will not register a trouble code. You should perform a thorough wiggle test on ETS circuit as described in Service Manual. Connections have been found to
be the problem in most instances. If no problems are found with wiring or connections, then a new
sensor may be necessary.
Thread Starter
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4th Gear
Joined: Oct 2007
Posts: 8
Likes: 0
From:
RE: Rough running
Well, I took the bike in to the shop today and they ran the diagnostic test and told me it is the download and that I need to install a race tuner and have it dyno'd. I talked to some other riders and they told me I can still get the download I need without installinga race tuner. The current download is causing the bike to run lean and thus creating my problem. I have a small local shop I am going to take the bike into to get the proper download. While it is in there I will have them checkout the fuel line in the tank.
Thanks again to everyone.
Thanks again to everyone.
Road Captain
Joined: Feb 2006
Posts: 521
Likes: 3
From: Virginia
RE: Rough running
I'm not a brain surgeon but would question why you need a new download. What specifically were the results of the diagnotic tests? I assume the bike has been running okay and this problem just recently started. Was anything recently changed on the bike that would alter the airflow? If it were me I'd look a little deeper into this before screwing around with the download especially if the bike ran fine and then started hiccupping without any changes being done to the bike. I fail to see how the download is causing the bike to run lean. If this were the case the bike would have always run lean since the download was installed. Something else appears to be wrong here. You don't need a race tuner unless you just have some cash you want to give away.
Don't forget, most of the time failure of the engine temp circuit / sensor doesn't generate any codes and could be a problem for you.
When my sensor failed I went to two Harley shops and both failed to find the problem. My third visit I made them change out the engine temp sensor and voila! Problem disappeared for me. These forums saved me from spending boat loads of money. Thanks to all those who post.
Don't forget, most of the time failure of the engine temp circuit / sensor doesn't generate any codes and could be a problem for you.
When my sensor failed I went to two Harley shops and both failed to find the problem. My third visit I made them change out the engine temp sensor and voila! Problem disappeared for me. These forums saved me from spending boat loads of money. Thanks to all those who post.
Advanced
Joined: Sep 2007
Posts: 85
Likes: 0
From: Union County
RE: Rough running
My understanding is that the temp sensor doesn't throw a code. Hooking the bike up to the scanalyzer allows them to watch the voltages at the sensors. They have to be watching when the temp sensor takes a dump and then it will be evident. I guess that is a tough one to find if it is intermittent.
Outstanding HDF Member
Joined: Aug 2007
Posts: 2,874
Likes: 8
From: Earth
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