CBR 929 FI Dumping Extra Fuel??? - TwoWheelForum: Motorcycle and Sportbike forums
 
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post #1 of 11 (permalink) Old 07-17-2006, 07:44 PM Thread Starter
 
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CBR 929 FI Dumping Extra Fuel???(Answered! Take Note)

Before I take my bike to a dealer which I hate, maybe you guys can help. I have a 00 CBR 929rr which is fuel injected. I went for a ride the other night and got one block from my house when the bike started running like crap; no power like it was on 2 cylinders. I limped it home and eventually took the plugs out and plug # 1 & 4 were covered with fuel. To make a long story short, the throttle bodies on # 2 & 4 are dumping extra fuel into those cylinders and i dont know why. The fuel pump and injectors seem to be working fine; i pulled out the injectors attached to the injector rail and they squirt a fine mist while cranking. While I was cranking with the injectors out of the throttle bodies, more fuel got into the motor in the #1 & 4 cylinder. Does anyone know why this would happen? There are 2 small fuel lines going to the throttle bodies; one is for fuel return but I dont know what the other is for...........anyone?

Last edited by Sprocket; 07-20-2006 at 03:20 PM.
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post #2 of 11 (permalink) Old 07-17-2006, 08:13 PM
 
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Plugs 1 and 4 run off the same coil. I think the coil is bad not the FI. The first test is to lay all four plugs, connected to their respective wires, on the valve cover. Crank the engine a few seconds while observing the plug ends. Probably only numbers 2 and 3 are sparking. Since the coils ain't cheap, as a final test, switch the coils. If numbers 1 and 4 now spark, but 2 and 3 don't, you need a new coil.
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post #3 of 11 (permalink) Old 07-18-2006, 12:30 AM
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NW took the words right out of my mouth... Its not extra fuel...the fuel isn't burning!

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post #4 of 11 (permalink) Old 07-18-2006, 08:31 PM Thread Starter
 
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Thanks NW and GM. NW; you are right in that I have no spark, what a bummer. Now I will search threads for the possible causes and cures.
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post #5 of 11 (permalink) Old 07-18-2006, 09:10 PM Thread Starter
 
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Ok, I have no spark at any of the plugs.
I've checked the pulse generator and it has a resistance of 525 Ohms.
The + terminal at coil connectors have .06 volts when the engine is cranking. Is that normal?
I checked the kickdown switch and it is ok.
What else can I check without sending to a shop?
Thanks.
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post #6 of 11 (permalink) Old 07-18-2006, 11:43 PM
 
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Quote:
Originally Posted by Sprocket
Ok, I have no spark at any of the plugs.
I've checked the pulse generator and it has a resistance of 525 Ohms.
The + terminal at coil connectors have .06 volts when the engine is cranking. Is that normal?
I checked the kickdown switch and it is ok.
What else can I check without sending to a shop?
Thanks.
You should have spark at plugs 2 and 3. Are you laying the plugs on the valve cover? The metal shell of the plug has to be grounded on the valve cover to spark. If none spark, you need a $20 digital voltmeter or $10 self-powered test light to check current at all your safety switches. Start with the kickstand safety switch first. If you bring it to a shop, they will do the same thing, but charge you. The pulse generator controls timing, at least on my 1990 CBR.
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post #7 of 11 (permalink) Old 07-19-2006, 12:38 AM Thread Starter
 
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Now the spark problem is fixed. I had the fuel pump wire disconnected so the fuel pressure wouldn't push the injectors off the rail while I cranked the motor and I didn't know this wire must be connected for the plugs to fire
So I have good spark but before I put the plugs back in I connected those 2 extra rubber lines that go to throttle body # 1 & 4; without the injectors connected and fuel got in the motor again. This was by gravity feed alone; i didn't even run the fuel pump before this happened.
Then I disconnected these 2 lines and cranked her over and it started up; however the high fuel pressure kept leaking from those 2 lines that I tried to plud off so I only ran it for a few seconds. I am wondering if the pressure regulator is working correctly so I took it off and will take it to the dealer tomorrow and see if they can check it and also ask them about the 2 extra lines going to the throttle bodies. Anyone know what those lines are for?
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post #8 of 11 (permalink) Old 07-20-2006, 03:28 PM Thread Starter
 
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Here's the scoop. Finally suspected my fuel pressure regulator was the problem so I took it off and went to the dealer. Service technician says "yea, thats a common problem. Whenever I get a bike that is running rich or flooding that's the first thing I check." NICE....What happens is the bad pressure regulator allows fuel to return thru the vacuum lines into the throttle body. This was unmetered fuel simply dumping into the cylinders and making it run extremely rich; in my case it would barely run at all!
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post #9 of 11 (permalink) Old 07-20-2006, 03:37 PM
 
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Great. How much does Honda charge for something that's "a common problem?"
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post #10 of 11 (permalink) Old 07-21-2006, 12:44 AM Thread Starter
 
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I actually have no idea what they charge for this if you take the bike to them and they figure it out. I took the regulator off the fuel rail and went to the dealer simply to see if they could check if it was bad or not. When I got to the service dept the tech knew it was bad as soon as I said fuel was coming out the rubber vacuum line. That was it and I left. The parts dept of course did not have it in stock; the regulator is $87 from them, so I ordered it online from Ron Ayers for $64

Last edited by Sprocket; 07-21-2006 at 12:47 AM.
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post #11 of 11 (permalink) Old 07-21-2006, 09:44 PM
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Yeah and that's one of those things you really need to buy new and not used.




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