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Discussion Starter #1
Hey guys,

I just finished rebuilding my 2008 F4 R312 after having it painted and she wont start. I've got spark, my new Shorai battery is fully charged, and the fuel pump primes correctly (starts, runs, then stops) but I don't think the fuel rail is being pressurized. I disconnected my fittings from the rail, cranked the engine a few times, but there was no fuel coming out. My fuel filter, in-tank lines, and outside lines are still pretty new since I replaced them at the beginning of this year. However, I just replaced my plastic female quick connects with metal ones to match my male quick connects (I was lazy and didn't feel like replacing both at the same time). The quick connects were sourced from Alex at GP so they're not the Chinese knockoffs. I'm gonna do some fuel flow tests after work today since I ran out of energy last night.

During assembly I accidentally plugged the 2 bottom left connectors in backwards. I think they're the side stand switch and speed sensor connections. I roasted the A1 fuse (first fuse on the left) a few times trying to find my mistake. The rest of my fuses look good including the ones on the starter relay. Is there a diode somewhere I may have burned out?

I'd appreciate any advice you may have since I have a race this Sunday :(

Thanks guys,
Chris
 

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You probably need to start from scratch with the fuel tank and pump. Make sure all of the lines are on the pump. I don't know if there are improper fuel fittings but I would check those to insure you have the proper ones. If you disconnect the fittings from the bottom of the tank and no gas comes out of the lines then the gas is not coming out of the pump
 

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Discussion Starter #3
I pulled the base plate last night and everything looked in order. I'm gonna test the fuel pump, fittings, and hoses today. I'll let you know what I find.

If anyone has made the mistake of plugging those 2 connections in backwards please chime in. I knew there was problem because my dash died after turning the ignition on. I really hope I didn't fry something other than the fuse...
 

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There is a diode down in the wires by the starter solenoid connector block. It's a 10c part and they will pop if for instance the battery is connected the wrong way around...

If you disconnect your fuel lines from the fuel rail then try to start, no fuel will emerge..The male connects are a stop valve when disconnected.

I suspect your problem is electrical as are 99 % of fuel problems : )

Best of luck.

Joe
 

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On the disconnects: there are differing lengths of protrusions that disable the check function. If your male ends are not compatible with your female ends, then the fuel will not flow.

Were I zany enough to try this, I would disconnect the return line from the rail to the tank, turn on the pump so it primes, then, while aiming the male end of the return hose at a bucket or suitable container, I would actuate the sleeve by pressing in and see if fuel flows. If it does, it will flow ALOT!!!!
 

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Joe, do the John Guest fittings act as checks when disconnected?
 

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Discussion Starter #7
There is a diode down in the wires by the starter solenoid connector block. It's a 10c part and they will pop if for instance the battery is connected the wrong way around...

If you disconnect your fuel lines from the fuel rail then try to start, no fuel will emerge..The male connects are a stop valve when disconnected.

I suspect your problem is electrical as are 99 % of fuel problems : )

Best of luck.

Joe
Thanks Joe! I'll check that diode tonight

On the disconnects: there are differing lengths of protrusions that disable the check function. If your male ends are not compatible with your female ends, then the fuel will not flow.

Were I zany enough to try this, I would disconnect the return line from the rail to the tank, turn on the pump so it primes, then, while aiming the male end of the return hose at a bucket or suitable container, I would actuate the sleeve by pressing in and see if fuel flows. If it does, it will flow ALOT!!!!
Joe, do the John Guest fittings act as checks when disconnected?
I bought the disconnects as a mated pair, so I hope they're the proper size. I'll check them regardless.

So I disconnected the john guest feed fitting from the rail and then primed the pump expecting fuel to shoot out. I even thumbed the starter switch. No juice. I didn't think those fittings had check valves
 

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Are you certain you got the supply fitting?
 

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Joe, do the John Guest fittings act as checks when disconnected?
Excellent point there Chuck !

No they definitely don't ! I just added a line or two to my post back there. Sorry to confuse...If you leave your fuel lines connected to the base plate then disconnect from the fuel rail you will find a very positive fuel flow once the the ignition is switched on and the pump primes.

Sorry I confused matters. I've amended my earlier post !

Joe
 

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Looking at the wiring diagram, the starter solenoid diode is not shown. I believe it to be there, but it is not on the diagram.

As to the point of reversing the side stand switch connector, it does look like it reverses polarity through a convoluted route and may be the culprit.

Check the diode.
 

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Chris:
Reversing the speed sensor and side stand plugs blows #1 fuse on an F4 and #5 on a Brutale (Gen 1)
When they're correct put a small zip tie on both sides of one connection......MV fucked up, should have
had a male on one sensor and a female on the other

John Guest fittings have no check valves

The CPC quick disconnects, male and female, have check valves and can be connected either way

:grin2:
 

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Discussion Starter #12
Update

So I found the problem...my new female fuel supply disconnect has a bad check valve. The o-ring inside looks out of round and it's starving my engine of gas. For those of you who may have this problem in the future, it's the disconnect labeled "out" on the tank's fuel plate. I swapped my stock plastic disconnect back in and the bike fired immediately :D

I checked the diode on my starter relay and it's reading .8 V one direction and .4 V the other direction. Doesn't this mean I have a bad diode? I measured the resistance while the diode was still connected to the circuit. Was this a mistake?

While I have the eyes of this forums best and brightest, would anybody care to guess why I keep burning out blinker relays? My LED tail light has integrated diodes and I have a LED safe relay. You can check my links so you know what I'm working with. I can't find any loose grounds and my connections look strong. The relays will last a couple hours of use before popping.

I'd like to thank everyone on here for your help! Looking forward to thanking a few of you in person next weekend :D
 

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Joe;
Go back and correct post #4

If you disconnect the John Guest fittings from the fuel rail and turn the key on......

You'll have fuel everywhere

:frown2:
 
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