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08 won't start

4K views 13 replies 7 participants last post by  wrencher60 
#1 ·
So I get plenty of fuel, noticed that while doing the spark check, didn't disconnect the fuel pump, shot fuel up to the rafters, pulled a plug and got spark while cranking with the plug grounded. 12.8 V at the coil, drops to about 11.9 when cranking. Damn thing still won't start. Checked all connections, all plugs are hooked up nice and tight. I'm pretty much out of options. Anyone have a similar problem with a fix. According to the manual, all should be good. I figure if it is sparking and I get the right voltage, the crank and cam position sensors must be ok. What does a bad ECM symptom look like?
 
#6 ·
Thanks, but it ain't the kickstand switch, that is real easy to bypass, and it only comes into play when the bike is in gear.
Same symptom as if the computer *thinks* the kickstand is down. Check the wiring and connections upstream of the wires going to the kickstand switch.

Also, here's an easy check. Put it in neutral with the kickstand up and start it. Pull in the clutch and then put it in gear. If it shuts off I'd say there's something wrong in the kickstand switch circuit.
 
#7 ·
Do you ride in the rain?

Check the kill-switch. My 600rr (same part) was having problems cutting out and not starting, and turned out to be crap/corrosion/water/etc. in the kill switch.

Opened it up, sprayed WD40 in it, and it has been fine ever since (2011).


edit:
Not sure if the kill switch kills ignition or fuel. Probably ignition...
 
#9 ·
Thanks for all the suggestions, but all these safety features cut out the spark and fuel by taking away the ground. I am getting both spark and fuel, that is why I am perplexed. I am beginning to hate computers, but there has got to be something else that I am missing. In my old way of thinking, if you get spark and fuel, the damn thing should start. When I switch off the kill switch the fuel pump doesn't work and I here the stop relay click, so I'm pretty sure that is working correctly. My bike just cranks over and over but never fires up, doesn't matter if the kickstand is up or down, in gear with the clutch in, or in neutral.
 
#10 ·
It doesn't make sense nor do some of the questions in light of what you see but...

Were you working on it when this happened? Are two plugs reversed. I know this is very unlikely/impossible but... People have plugged a Z Bomb into the wrong connector so?

I believe that the kill switch controls the plus side, not ground. I think the ECU completes the circuit to ground. The Tip over sensor is in line with this but it would have the same effect as the kill switch.

Is it all working when you are not cranking the bike? When you crank the bike over the voltage is going to be lower. Did you have the plugs out when you saw the spark and the fuel?

Crankshaft or camshaft position sensor. Throttle position sensor?

Like you say it can deliver fuel and spark. So it must not do either or at the right time. If the timing were bad I would expect backfires etc.If the sensors weren't working I would expect an error code. Does it smell of unburned gasoline as in flooded?
 
#12 ·
Ok, here is the deal. I followed the manual troubleshooting guide. Pulled off the coil connector on the #2 sparkplug, got 12 volts there. That tells me that all the relays are good, the kill switch is good, and the BAS is good. Pulled the plug, hooked the coil back to it, grounded the plug to the head, cranked it over and got spark at the plug. Then I hooked the fuel pump connector back up and cranked it over again and got all kinds of fuel pressure to the fuel rail, shot it up to the rafters. Just for shits and giggles I disconnected the sidestand plug and checked for continuity with stand up and down and verified it was working. You were right about the kill switch taking power away and not ground. Both the BAS and the kill switch power up the relay. The side stand supplies one of many grounds to the ECM along with the neutral switch. I didn't screw with the timing or anything, and wasn't working on it at the time. My battery got weak so it wouldn't start unless I put a charge on it. Put a new battery in it, and all worked great for about a week, and then this problem started where it wouldn't start. I would hate to think my ECM just took a shite, but that is what it is pointing at. I'm going to check the TPS next to see if it ohms out nice and smooth. Last night after messing with it for awhile I did get the flooded smell because I tried cracking the throttle wide open and then off to see if that did anything, but still no luck. Battery voltage only drops down to 11.9 while cranking so I think it is charged enough. Been keeping the battery tender on it.
 
#13 ·
maybe i missed it but have you tried a different battery?

had similar prob after a long period of storage, the battery volts were all good and would turn the engine for a long period.
i finally hand the bat checked and its CCA was reduced from 120 to 80.

RR8 engine needs to crank fast and my old battery wasn't up to the speed
 
#14 ·
So here's the story. Plug was out when I did the spark check, don't know of any other way to do it. Fuel hose was disconnected from the rail and shot up as high as the rafters when cranked. I don't recommend this check. Side stand switch ohms out good, continuity when up, and open when down. Kill switch kills power to the fuel pump by way of the engine stop relay. All plugs connected correctly, like I say, I get voltage at all the right places. Fuses are good, removed and inspected just to be sure. Voltage drops from 12.7 to 11.9 when cranking, so I should be good there. I can smell fuel if I crack the throttle wide open a couple times while cranking. Read somewhere to try that, and then try to start it normally. I'm open to any new ideas before I try talking to a dealer tech about my problem
 
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