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Discussion Starter #1
Hello. The usual story..long time lurker, first time..blah blah.
I signed up not too long ago to research Bodis pipes, but have been doing more research on a fuel pump ( I think ) issue. There were a couple of posts that similar...but I still haven't solved it.
Started off two days ago. Bike was was runnng fine...stopped for lunch...started back up, and within a minute, the fuel delivery was sluggish until over a certain RPM. There is a very similar post about this..but...this changes.
I made it to a friend's house...let it sit...and then it wouldn't start.
Trucked it home, researched here..and tried a few things...read the post about jiggling the wires, and that was all I could do for the night. Battery finally recharged...started right back up.
Put the battery cover on today...two trips around the block..ran good...just a couple of backfires.
Take it on the highway...and bam....a repeat of Saturday. Trucked it home again.
The first time it happened, I couldn't hear the fuel pump. I have a F4 750 also, and that really sings when the ignition is turned on. After the bike sat for a while, and I jiggled wires and relays and whatnot..and the battery was charged,
I could hear the pump, but it is much quieter than the 750.
Anyway..now....no fuel pump noise.
History on the bike...I just got it in April...it is a 2005 F4 1000S, and had 800 miles on it. It now has about 1200. The dealership said the previous owner tried to start it, and it wouldn't, and I guess he ended up
trading it in, or selling it. The dealer said they replaced the fuel pump and the lines. I haven't contacted them yet, as I was hoping it was something simple.
Is there a way to get check if power is getting to the pump without taking the tank off? Thank you full gas tank.
I checked the fuse...the relay on the left side seems to be OK...I swapped it with the 750, and it made no difference.
I have the EBS relay pulled out from the frame (still connected), but being a sealed unit, I am not sure if it can be checked. After reading hours of posts, most of the info is blurred with Bodis pipes :)
One other thing...I am pretty sure that the 'choke' worked before..but now it doesn't. And one time it failed to start a few weeks after I got it, but it did after a few attempts. I blamed that on bad gas that was still lurking around.

Not sure if anyone is around from the Yahoo MV group days, but I was on there back in 2003~ or so. I just tried to log in, but they wipe you after a year.
I had the silver 750 that the battery blew up and etched the entire rear end, and I ended up getting the parts powdered purple.
Well...now back to searching...thanx for reading.
mike
 

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Hi Mike.
Your problem sounds battery related, I know you say you charged it, but those short stints and then dying points to battery.
Have you tried swapping batteries between the two bikes ? Be carefull, you'll be aware the batteries go in on their sides I imagine.
When you say the bike wont or wouldn't start, does it turn over at all with the starter motor ?

If you've eliminated the battery, then I'd suggest you pull the tank and check fuel cap vent lines, a blocked vent/breather line can cause starvation problems, this can usually be picked by opening the fuel cap and listening for a sucking sound.
 

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If the pump is not turning, or turning weakly, it is electrical power delivery.
The tank comes off very easily and draining it is simple with a hunk of tubing and a bit-o-suction...ala syphon.

You need to pull the tank. Check the fuel lines are appropriate. Check the vent path. Check power to the pump connection with a volt meter. Check that the evap cannister isn't causing the problem by passing charcoal to the fuel system. (Caused by overfilling the fuel tank)
 

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Discussion Starter #4
Last night...I checked the power to the fuel pump fuse, and it saw 12+v for a second after the key was turned on. The bike would turn over, but there was no fuel pump activity at all. I put it back on the tender just to keep the battery charged. I was thinking that maybe when the battery died after the first time, it reset something electronically.

Came out to possibly take the tank off..and it started right up. I had plans to disconnect the battery to see if there was a possible electrical reset..but the battery didn't lose much charge this time, as I didn't keep hammering the start button like the first time. Fuel pump can now be heard priming. I let it run until it warmed up..and when I roll the throttle, it sputters until it breaks over 4-5000 rpm or so.
Not too sure, but I am thinking fuel delivery. A couple of posts on here mentioned loose wires being resoldered on the pump, but it seems like there isn't enough fuel getting being delivered. Or..I guess it could be too much, but neither explains the slow shutoff while riding. I am hoping it can be narrowed to the pump, and not some mysterious electrical problem.
 

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It's not the pump, it'll either work or it wont. Pull the tank, go through the fuel lines as suggested, this is common for such an old bike and often discussed mate.
 

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Discussion Starter #6
Just confirmed from the dealer that a new pump and lines were put on before my purchase..so about 400 miles ago. After the bike started today...the second time..it ran for about 30 seconds and shut off. Pump hasn't made a peep since. So yes...the next step is the tank.
thanx for keeping an eye open.
 

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Always keen to see what's the next curve ball coming our way mate. The more info you give us the better feedback we can give, or the more accurate for lack of better English.
Good luck, makes sure somebody holds the tank for you as you undo the Fula lines etc.
 

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Discussion Starter #8
I have been on here looking at all of these old pump/fuel problems. Some are close..but not the same. The pump works and then it doesn't. I was going try to record a video of the issue earlier, when the bike was running for that 30 seconds..and I finally got my camera switched to video just as the bike shut off.
About a half hour ago, I swapped out the latch relay and the power relay with the 750, and there was still no pump priming. I was looking at the schematics, and I was trying to find #20 Main Relay. Is it supposed to be on the right side near the tail?
Probably way off with that one...I was just trying to eliminate easy things first. Whatever the three relay type devices are on the left..the one with the diode...I might do those tomorrow if they are worth swapping. I already swapped the relay on the far left (of the three that are mounted to the frame) and that wasn't an issue.
 

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Discussion Starter #10 (Edited)
Latch relay...I swapped out both relays under the tail with the 750, no change.
After it shut down for the last time...the pump is back in "no prime" mode :)
I just went out and checked..there is a second of 13+ voltage at the fuel pump fuse when the key is turned.
 

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Mike the pump gets voltage once ignition is turned on to pressurise the system, there's a relief valve in the pump plate (regulator).
You can swap ECU's between the bikes, you just have to keep the EPROM chips plugged in to the specific bikes.

I understand you're reluctant to remove the tank, but if I where you I'd swap the tanks between the two bikes, that way you eliminating sooo many variables.

Don't take for granted that the shop swapped out fuel lines in the tank, there is still the question of what fittings are on the external fuel lines (some of the fittings don't open properly or have O-rings which swell up causing fuel starvation), is there still a carbon emissions filter in the tank, did they replace the fuel filter etc?
And don't forget that fuel cap breather, although I'd not put money on that at this stage.
 

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Is the fuel filter fitted in the correct direction, there is arrow on the body, easy to get it wrong.
 

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It does sound like starvation....
 

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Mike the pump gets voltage once ignition is turned on to pressurise the system, there's a relief valve in the pump plate (regulator).
You can swap ECU's between the bikes, you just have to keep the EPROM chips plugged in to the specific bikes.

I understand you're reluctant to remove the tank, but if I where you I'd swap the tanks between the two bikes, that way you eliminating sooo many variables.

Don't take for granted that the shop swapped out fuel lines in the tank, there is still the question of what fittings are on the external fuel lines (some of the fittings don't open properly or have O-rings which swell up causing fuel starvation), is there still a carbon emissions filter in the tank, did they replace the fuel filter etc?
And don't forget that fuel cap breather, although I'd not put money on that at this stage.
Best advice here is and like Donsy said, swap the tanks around with the 750. This will narrow it down quickly.
 

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Discussion Starter #15
As of right now..the pump primes when the key is turned or the on/off button is pressed. And it started. I can't see how it would be a fuel starvation or crimping issue when the pump intermittently works and doesn't. Seems like electrical to me. The bike ran fine for 400 miles before any issues developed.
mike
 

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That still seems like fuel starvation/pressure problem to me. I think you're putting to much into the pump on/off priming issue, but I'll humour this fault and look both ways :ahhh::).
This is me on the other side of the world doing fault finding, so take it for what it is, hopefully some of or real smart forum members will club in too.

1. What external fuel lines are you using on this bike ? Just out of interest.
And when where the plugs last changed, not thinking it's them, just ticking the boxes.

2. The fuel pump (14) is controlled/protected by the same fuse supply that looks after your coils and injectors, so electrically this could be a common fault, look at the incoming or r/h side of the fuses F6&H8 in the drawing. These two fuses in turn get their feed via the Power (8) relay which is protected by fuse G7. So there's a lot of room for bad connections.

3. The way the bike is spluttering can also be a temperature compensating problem caused my mapping, might be worth swapping the air pressure sensor which is on the L/H air intake tube just in front of the handlebar.

4. You did say you swapped the General feed relay (20) or Power relay (8) right ?
The Latch (7)(right side of ECU) and Power (8)(left of ECU) relays are identical so you can just reverse them on the bike.

Hope this helps, good luck mate, let us know how you get on.:conveyer:
 

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Discussion Starter #18
After sitting for hours..not on the tender, just to help rule out batter issues...the pump primes and the bike starts once again. Both relays 7 and 8 were swapped out before, no resolve. Is what you are calling the general relay (20) the same as the schematic #20 main relay? Is that the far left relay mounted with the other two relays on the left side? If so, yes, that was the first one that was switched. Also, 14 on my paper lists as the Engine RPM sensor.
Is there some reason that these problems are just coming to light after 400 miles, such as mapping?
thanx again.
 

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Your fuel pump is triggered on by a signal form the ECU when certain conditions are met. Those condition are in the trouble shooting guide in the Shop Manual. Something within that sequence is not happening.
 

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There is also the possibility of an intermittent open in the circuit...you know, a bad wire or connection.
 
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