i have a 04 yellow 599 with 33,000 miles , and when i took it to the dealer it took them 2 and a half weeks to actually touch it when they werent busy and when they did diagnos it they sold me on a part that really didnt solve the issue which was a pulsar coil. anyway i pulled my bike out and i sat down and went through every step in the service manual and if the test are true and not misprinted its pointing to a bad tp sensor. well ok let me back up and describe whats its doing.

start it kinda runs alittle rough tach needle just bounces between 1 and 2500 rpms idleing....when i try to rev it above 8grand it pops,and backfires just raising all kinds of hell ,timings not but maybe 1 or2 degrees off...now heres the kicker just for grins i unplugged the hot wires on the coil packs just to see what it'll do 1-4 nothing or very little to no change.. pull 2-3 off dies instantly.. swapped the coils around problem stays on 1-4. why is that?

maybe the ignition module?? not firing the 1-4 side the tps shouldnt affect just 2 cylinders

well in the book if the timing is off its condeming the ignition pulsar coil which is the part i just replaced but didnt solve anything or the icm..which im kinda scheptical about condeming the icm...i dont wanna sink $300.00 on a computer and it not solve the problem. cause once i buy it no refunds.. now i know on honda cars if u have a bad ground somewhere itll make it run like crap.... now i did do a test on the tp sensor ,i checked the pins the book told me to check no reading but i looped it from the middle pin and got a variable reading ...im so confused at this point :idonno

set ur meter to read ohms and hook one lead the the tps signal wire terminal and one to the sensor ground wire terminal with the sensor unplugged if you slowly open the throttle and watch the meter there should be a steady rise in resisitance with no drop outs or glitches as you open the throttle ...... make sure there is reference voltage at tps harness side and check the sensor ground wire against body ground to see if it is good ...... just a quick way to test the tps if that will help you any ? hopefully you understand what I mean as Im not good at describing in words I just know how to do it but cant say it :D did you mean have cylinders 1 and 4 that have no spark at all ? cuz if so cant see the tps causing that but it can cause an idle fluctuation.

did you mean have cylinders 1 and 4 that have no spark at all ?

Well, when I run the bike with the 1/4 coil disconnected, the bike is weak, as it's only on 2 cylinders, but it runs without trouble. When I connect the 1/4 coil, the bike starts popping and raising hell and backfiring. If I start the bike and disconnect the 2/3 coil (with the 1/4 coil still connected), the bike dies almost instantly. I have checked for spark on the #1 and #4 plugs and there is spark. Also, hooking a timing light up to the #1 plug wire reveals that the timing is pretty close to correct, it's a little off but not much.

I have swapped the coils to no avail. The same problem occurs on the same cylinders. The spark plug wires don't look bad either. The Pulser coil has been replaced. In my mind, the only thing left is the ICM.

Also, I checked the TP sensor and it appears to be good. This problem is driving me nuts. :(

Thanks for the help so far guys!!! It's much appreciated!

If the timing is right on 1/4, and swapping the coils didn't change anything, I would guess the ignition module. Does it have just one pulse coil to sense crankshaft position, or one for each pair of cylinders? Also, is there a camshaft sensor, like on a car, or is the pulse coil the only input to the module? Seems that the pulser is doing its job if timing is good and 2/3 run good, as are the coils. I think the TPS is there to tell the module when to advance the timing, also may have something to do with the decelleration fuel cutoff the '06 has. When I test a TPS, I leave it plugged in, key on engine off, and carefully slide a pin into the back of the connector alongside the signal wire (the one that doesn't show ground or fixed voltage on a voltmeter when you roll the throttle). If you connect your pos. voltmeter lead to the signal wire, ground your neg. lead, and roll the throttle slowly from closed-open, hold it, then roll slowly open-closed, you should see steadily increasing, then stable, then steadily decreasing voltage. Go slow, a meter doesn't respond fast. An oscilloscope is better if you have access, it will graph the voltage, and you may find a glitch, or a dropout momentarily. Hope this helps, good luck!

well then my initial thought stands as is just my 2 cents yeh to test voltage on the tps it has to be plugged in .....and you/most people probably dont have an oscilliscope so a meter works fine it responds immediatley but may be hard to see very small quick glithches if you have one that has a spread graph under the digital readout any glitches will be easily seen on it :thumbsup

back in the 70s I had a CB500/4 It had the same problem i changed the plugs and it cured it why no do the same if the prob persists