01 f4i, Fuel, spark, compression, No start. Injectors not working.
 

Just as the title states: I have compression, I have spark (actually put new plugs in about 30 miles ago) and the fuel pump is priming, and I have pressure at the rail.

My issue started a couple of days ago. I had the bike running the night before, rode it around the block just to run it and kill a few minutes. It ran fine, made it home no problem, cut it off like normal, that's it.

The very next day I went to start it after leaving the battery on the tender all night (Old battery was giving out) fuel pump primed, everything seemed normal, only it won't start. Just cranks and cranks. At first I thought it must have been that the battery was just finally shot so I got a new one, but it still wouldn't start.

After that I ripped the bike apart and checked the plugs for spark, and compression. Both are good. Then I went to the fuel system, made sure it had plenty of gas, made sure the pump was pumping plenty, and made sure I had pressure all the way to the injectors. Then I decided to check and see if the injectors were misting like they should. I opened the throttle to see down in there and cranked it to see if it was misting and it did the first time and ran for about 3 seconds, after that absolutely nothing. Can't get it to do it again.

I've looked and looked on forums for the last 4 days and I haven't found an answer. First I thought it might be the tip sensor but the fuel pump is priming so it shouldn't be that, I've also seen it might be the ECU but I can't afford a $300 ecu off ebay, especially not a whim hoping that will fix it.

Any suggestions or advice is greatly appreciate. Mainly looking for anything and everything I can try before I have to give in and get an ECU, I'm just a poor boy who desperately wants his crappy old bike to run. This little incident has already cost me a big road trip I had planned at the end of the month. :(

Apologies for the text wall as well.

Well, lets go with the easy stuff first. Is the button on run by the throttle? haha.
Amazingly enough, out here in dry ass, no humidity Arizona, I've had two friends with corrosion issues on the main electrical harness connector since they aren't weather tight [Hondas one big F up on the bike IMO] so perhaps check the connections to make sure signal is getting to the injectors. Trace that signal back to the ECU and that should give you an idea. I'm not an electrical expert so I don't know how to go about this exactly.

I was thinking about tracing it as well. Maybe pulling a wire or trying to see if I can pick up the "pulse" signal coming from the ECU on a multimeter. That would tell me if it's an ECU problem wouldn't it?

And yeah, the button is on, lol! My bike won't prime the pump or crank if the button is off.



Another thing I'll mention, dunno if it's valuable information, but while I had the injectors removed and unplugged I noticed the fuel pump wouldn't prime, so it seems the ECU is aware of whether or not they're plugged in. Once I plugged them back in the pump would prime again.