Intermittent stutter

[sharrison8]

I have an 03' xb9s with about 26k miles, stock except an upgraded ecm.
It will stutter (i will get no throttle response) for a second, the engine light will come on and it will go back to normal with the engine light still on, and an occasional stutter after. Also when I shut the bike down afterwards the fan will not come on if the engine light is on and it will not start back up immediately after shutting down, if I come back 10-15 mins later it will start right back up.
It only does this when it is warmed up and cruising for a couple miles, and it sometimes will not happen at all.

Thanks for any help.

 

[Stevenc150]

Before you do anything, give all your fuses/relays a once-over to make sure they're seated well. Check your battery terminal connections and trace your grounds, especially the frame ground, to make sure they're not corroding or loose.

Then check to see if you have stored engine codes, which sounds like you will. Order you an ECMSpy cable off of Xoptiinside.com and download the program off of Buellmods.com - downloads section. VERY helpful for troubleshooting... In the meanwhile, you can use the wire jumper method to test for engine codes: Checking codes w/o ECMSpy

 

[sharrison8]

All my connections look good, I found a pinch/soft spot in a wire coming from the ecm it is red/yellow, it got pinched in where the seat hooks in.

Also figured out my intake seals are bad
Spark plug wires are old and cracked up

 

[jimijeans]

After you check the codes, plus it might be time for some wear items to be changed out. The older Buells ECM Spy program is great even if you use it only for Diagnostics/Troubleshooting etc..New plugs and new Plug wires If the fan is orignal might want to get a new one while they are not so expensive at this time. The intake seals are not to hard to do just take your time and mark if needed for reinstalling. Once done with your repairs then a TPS reset will keep the bike idling properly.The fan after checking for codes may be OK for now but with the miles on the bikes Engine cooling the rear Cylinder is key to a longer lasting and better running Engine. Not to mention your legs will need it cause will be hot in a couple of months.Post up when done.*Jimi

 

[sharrison8]

Thanks a lot for all the help.
I ran for codes on ecm spy and got nothing I have changed out the spark plugs and wires since I posted I have yet to do my seals though.
Can you run for codes while the bike is running?

 

[Stevenc150]

Codes are stored so if you've got one, it'll show up with bike off. No need to have bike running, but to answer your question - Yes you can read your codes with bike running. But it sounds like you found the culprit when you found the bad intake seals right.

 

[sharrison8]

I'm hoping so! I am going to try and get it done this weekend, and I'll let you guys know how it goes.

Thanks again.

 

[sharrison8]

Changed out the intake seals, problem persists. I noticed the fuel rail is slightly bent up so the velocity stack isn't sitting all the way in the manifold it just barely floats above it.

 

[jimijeans]

Sharrison8 after you finish those items if the problem still persists, have you tested the fuel pressure? if pressure is close to 42lbs and [above] that will run the bike. If the engine light is coming on then perhaps the Temperature sender that controls the fan OR wiring is rubbed in a small area somewhere and it runs across the rear of the rocker cover and down inside the top of rocker cover area, a crows foot should break it loose. The wiring sometimes wears bouncing around and maybe slightly shorting out against something. Most times depending on the program in ECM the fan should come on when Ignition is turned off after it is warmed up then shut down(as long as it has reached temperature). Some of these bikes do have a studder here and there but not what you are experiencing. Might want to check the Temp/sender to see if it is working properly.Check all your relays also. Do you have the Orignal ECM? You can find the fans wiring plug and test the fan seperately. Several times here in the shop I have found that a worn fan may work on high but the low speed from which it starts out in the beginning and then goes to the second speed(high) will cause NO Codes but the Engine light will come on. Due to currant drain and higher temperatures. Most times Depending on Temperature the low speed comes on but you don't really hear it due to Sound around you and if Temp still continues to rise(like Traffic) the High Speed kicks in. I'm not there to see so sometimes on something like this we have to cover it all. Low volume on the fuel pump will make the engine light come on but doesn't always set a code. Theres a fuel filter in the tank[usually] could possibly be clogging unless someone changed it at the proper mileage (14 TO 17'000miles)Fram makes the proper filter(napa)#3095 small can type filter. I know it is furstrating but hang in there and good luck. post up when can.*Jimi

 

[jimijeans]

Sorry I ment to break that long post up for easier to read. Make sure to check the filter part number they change a lot now days.Always change the clamps & hoses on the inner filter.*Jimi

 

[sharrison8]

I got the stack set back in, still need to resist the tps. I think it has a race ecm, and I know it has a dobeck fuel system in it.
But I will def. check out all you listed and keep you updated. Thanks a lot!

 

[sharrison8]

So it turned out the engine temp sensor went bad, replaced it.
The stutter and light are gone, finally! But when I shut the bike off, even after a long ride, the fan isn't coming on.
Before I replaced the sensor the fan would kick on when I didn't get an engine light at shut off, so I'm pretty sure the fan works.
any suggestions?

 

[Stillonit]

maybe the new sensor is now reading the correct temp and it doesn't need to come on... my 2010 never comes on when I shut the bike down. But it has a different fan profile program.. happy you got er running good again.

 

[jimijeans]

Glad it was just the Temperature sender. check your connections and the fuse to your fan.the add on dobeck(fuel pack)might interfear with the Proper operation of the ECM program.
Make sure the fan is coming on by Letting the engine idle for a few minutes till it comes on. After the Fan comes on shut down the Engine and if the fan doesnot run then you might want to remove the Fuel Pack add on. The 03Xbs ran the fan by temperature on stock/race Ecms, after the Engine and Power was shut down,depended on how high the temperature was .
The Altered race usually the fan run program Stock OR Race on older model bikes stays the same on purchased equiptment of those years of Engines.Unless the ECM
is individually Tuned with ECM Spy for older models. The 08+ XB/Buells the fan run program, Stock/runs all the time while riding and also by temperature as needed.*Jimi