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Crisis
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Discussion Starter · #1 ·
I went a few days riding in Luxembourg and on my way back to the Netherlands I filled up at a non-descript petrol pump with 98. Shortly after filling up the the engine management light popped on, the engine started running rough and started cutting off at idle. While riding it seemed to be running fine at higher rpm's. While being 200 km form home I decided to leave the back roads for motorway and get home and see what's going on back home. Had somewhat same issues a few years ago in Italy, also after a fuel stop, so suspected a case of poor gasoline. Took the fuel tank of,drained it, and while everythings off also changed spark plugs and cleaned the air filter. Didn't drain the throtle bodies, so if it was bad fuel, there was still some there. Got new fuel. Took some time to get it started, barely managed to get it running, whith also an occasional backfire in the inlet, but after a few minutes it runned better (still far form perfect), but it didn't cut off at idle anymore. Bolted everything back and took her out for a spin. While driving mostly between 3500 and 4500 rpm it didn't run smooth, engine management light still on. Felt like the engine didn't get a steady air-fuel supply, and had some ocasional backfire when closing the trottle.
Got home and decided to try to find the cable to hook it on TuneECU. Hadn't done that in the first place cause I hadn't hooked it up in 7 years or so, and had no clue where I left the connecting cable years ago, but found it after a couple of hours turning the place inside out.
Got a read out, P1502, inlet air temp sensor, but that one didn't come back after erasing the fault codes. The other read out was P0505 idle speed control system malfunction, which kept coming back after erasing. The manual states as a possible cause 'stepper engine/cable damage'. While cleaning the air filter earlier on I also took a visual at the stepper, but didn't see anything out of the ordinary, whiped with a cloth a little bit of soot out, but didn't check it's working. I assume (assumed?) the stepper only controls idle and a possible non/bad working stepper doesn't affect the way the engine runs at above iddle rpm's. As being more familiar with carbs electronics ar not my strong suit and I might be very wrong in my assumption about what a faulty stepper might mean. Any ideas what might be possible causes and how to check? Any advice is welcome. It's hard enough to find a shop who's a bit familiar with these Benelli's in the proximity and even then, as it's July there's no chance to find anyone available before september.
Currently my RS is at 68.000 km. Alex (Maniac) had it thoroughly serviced at 60.000 km and installed upgraded injectors and a corresponding mapping. Coils have been replaced at somewhere around 45.000 km as I remeber, and nothing further to remark about the injection plant. Made a picture of the diagnostics page earlier today:
Font Personal computer Display device Computer Multimedia
 

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Check your TPS as well, they can get "burnt " in the middle and bugger up the running, had one that jumped from 3000 rpm to mid 7000 on a steady throttle opening. Fuel is obviously the first suspect as you had just filled up, but stepper and Tps are the more likely culprits.
 

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I would think if you are getting an error it is probably a cable connection or winding in the stepper fault, because the ecu cannot know if the stepper is actually working, but could sense if there is no current feeding it (unless it looks at lambda readings to see if it changes with the stepper action) But I am only familiar with the Walbro ecu. A stuck open stepper could cause too much air to enter the engine and give a weaker mixture above idle.
 

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Crisis
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Discussion Starter · #4 ·
Thanks for the suggestions guys, got some work to do. freeatlast, I assume with TPS you refer to the throttle body group position sensor.
 

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yes , simple enough to change and then reset using the tune ecu set up.It does not need to be Benelli part, I am sure I used a Citreon/peugeot one about £30. two phillips head machine screws and the plug connector. On a Trek , you dont even have to strip the bike , you can get at it through the frame. On the Rs you need to get the top right fairing off.
you will know as soon as you get it off if it is toast.
 
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