MV Agusta Fueling

[nick5446]

I'm hoping this is one of those issues where just talking/typing through it gives me some sort of epiphany...

I just picked up a non-running 2004 Brutale 750 that supposedly needed a fuel pump. I pulled the pump from the tank and quickly noticed that the hose from the pump to the filter was disconnected, so thought I got lucky. I put it back together and had fuel flowing (though I don't know how much), but it still wouldn't fire. Pulled the injectors and they’re not spraying. Does anyone know how much voltage they’re supposed to get, and if they’re always getting it whenever the key is on, or just when cranking/running?

The bike has a DynoJet Power Commander. It’s been years since I’ve dealt with one of these, but I pulled the manual and found that it taps off of the TPS via a splice. That’s getting about 9V; does that sound right? I can’t find it in the MV manual, but I’m assuming it should be 12v and that’s my problem.

By the way, it does run on starting fluid!

Any tips or ideas are greatly appreciated! It's got a few other weird electrical issues that I haven't dug into yet, but I'm reeeally hoping it doesn't need an ECU. FWIW, none seem related to this (brake lights don't work, fan switch overridden, one turn signal out, etc).

DynoJet manual: https://www.dynojet.com/amfile/file/.../product/3856/

MV manual: https://www.teamdouble3racing.com/ma...manual-ed5.pdf

[Kurlon]

Unplug the PC, get the bike running without it first, save yourself that potential headache.

TPS will be variable voltage based on throttle position, no idea what the viable range is on that bike though.

[Paul_E_D]

I'm with stupid ^ Get that TC device out of the mix.

[boosten lebaron]

Agreed with the rest. Ditch the PC. Set up a little 9v battery test stand to see if the injectors are even spraying. It's easy to do. 9v battery to the injector (polarity doesn't matter) and spray some carb cleaner in the inlet side. Off the bike of course. You can get fancy later with a rubber tube and put actual pressure on it later but for now your just looking to see if they open and let fluid pass.

[nick5446]

Sweet, thanks! Yeah, to be honest I didn't realize I could just unplug the PC without upsetting something else, but I'm all for reducing variables

[nick5446]

Well, as usual, I'm an idiot.

I pulled the PC connectors and it fired right up, running good, if a bit rich. I started removing the whole PC harness and found the ground lug...disconnected. Gonna go out on a limb and guess that was my real issue. I'll try reconnecting it later and see how it goes.

Thanks for the help!

[FriskyDingo]

Good deal, enjoy the new bike!! I'd imagine not the easiest bike to find parts for at this point...