Injection Electronics

Electronic Fuel Injection

Since 2007, all Harleys have fuel injection. End of the fun of changing jets and adjusting needles on the carburetor. All over? If you're talking about physical screws, yes ... But: modern injection systems are controlled by an electronic engine management system and, as with any other computer or microcontroller, you can of course intervene in the programs and routines. In other words, you can turn virtual adjusting screws. However, you can't get any further with the injection system without prior knowledge, which is something it definitely has in common with the carburetors.

Do I have to readjust the injection system after fitting accessory air filters?

With all accessory air filters, it is to be expected that the air volume will increase compared to a standard filter. However, more air does not automatically mean more fuel. Custom air filters may therefore require the mapping to be adjusted in order to reliably prevent a lean mixture. The consequence of a mixture that is too lean is a loss of power or even mechanical damage due to overheating. Harleys generate the most power at around 10% excess fuel, i.e. a rich mixture. The unburned fuel then also cools the combustion chamber.

In closed-loop operation, i.e. with lambda sensors at operating temperature, the injection system adjusts the mixture composition itself within certain limits. The necessary adjustments therefore mainly affect operation when cold or when the lambda sensors are not active (for whatever reason).

How can I intervene in engine management?

For the electronics of Harley-Davidson motorcycles with fuel injection, we offer solutions for optimizing the engine management: Dynojet Power Vision or FP4 from Vance & Hines, depending on whether a smartphone-based solution is required or a Windows PC is available.

Does it work for chip tuning? Does it give me access to the software?

Quite frankly, yes. There are a few areas that remain inaccessible, but you can access most of the functions. Whether you want to do this and to what extent is up to you.

The devices are usually connected to the diagnostic socket via a cable and address the control unit directly. Error codes are displayed and can be reset. In the event of a fault, the mechanic has an indication of whether and which part of the electronics is not working. Without the need for a dealer.

Many Harley-Davidsons with fuel injection suffer from jerking in the partial load range or delayed throttle response. This can be remedied by correcting the mapping. According to personal taste and in your own garage. There are large libraries of maps available for Power Vision and Fuelpak, which you can install on your own vehicle. Optionally, of course, everyone can do it themselves. Tips are available from the manufacturer and from the community on youtube, and of course also from W&W Cycles.