Hitchcocks Forum

I have a 2014 b5 U.C.E. The problem is when you close down the throttle there is a severe lurch as the deceleration fuel cut off activates.As you open the throttle again there is another lurch as the injector switches on again.The chain tension is correct.Has anyone else had this problem and is there a solution .Thanks.

Tickover is below 900rpm?

Not sure what the tick over RPM is but have adjusted it up high and low using the air bypass screw,but it still cuts off the injector too early.Do you think a power commander unit will help?

I do not have sufficient knowledge about fuel injection to comment. (However I did cure our Toyota Yaris which kept stalling by using Wurth Air Intake and Injection System Cleaner.)

Are the throttle and bi-starter cables correctly adjusted?

It could be a number of things. Is the throttle sticking? There should be a distinct click as the throttle is closed. Are all the sensors clean and properly connected? A likely candidate would be the tps (throttle position sensor). It could also be that the tps voltage is set outside of the correct range. I assume there are no faulkts stored or showing? To check for stored faults ground the spare earth cable attached to the ECU,switch on the ignition but do not start the engine. Look at the MIL (malfunction indicator light). If a fault is stored it will flash a series of short and long flashes. The sequence will indicate the potentialproblem. Be aware that a current, as opposed to stored, fault will show up by the MIL being lit permanently when the ignition is on. It could also be the MAP sensor connection. To a degree the EFI on these bikes can be a bit jerky off idle anyway. Also, I don't think that the EFI shuts off the fuel flow when the throttle is closed. It could also be a leak in the air intake. be aware that a leak causes a rich mxture, not lean as would be the case with a carb. Power Commander? Shouldn't be necessary unless the exhaust or air intake has been modified. Personally I got sick of diagnosing sporadic faults with the EFI on my 2015 C5, including the one you had. I cured it by putting a carb on it - cheaper than a Power Commander and more easily tweaked to suit changes in intake and/or exhaust. bye bye problems. Thoroughly recommended. Others who have more patience will take a different view, but to me the EFI looks odd without the carb there and I like having a proper choke that doesn't require a double jointed thumb to hold open and a nice disgustingly anti-green, fire risk tickler. Just me.

Not sure if it may be the Same issue as my C 5. Check that the air filter has the plastic cover over it inside the airbox. If not you will have a huge flat spot when closing and opening the throttle. See my post from a couple of weeks ago.

Hi I have similar problem on a 2016 B5 but I put it down to slack primery chain I believe there is a hydraulic tensioner on these things if irs jammed or not working could give same result does it in every gearclose open clunk clunk prefer the old iron barrel system.

Hey Rattlebattle how hard is it to convert to a carb? Do you have to take the crankcase off and do things inside there?What about the fuel pump etc.?

On the subject of carb conversions...does anyone know if the connected injector solenoid still believes it's metering fuel?