fuel pump issue

[uri gal]

Hello all

I guess owning two vmax’s that mean more posts LOL

The issue with the fuel pump on my 85– its seems to have no fuel from the pump when the bike is with a full tank of fuel

I tried to read other posts but its won’t help

I can tell that:

I checked the Fuel pump connector – when I switch the ignition to “on” while motor not started:

1 – when switch fuel is “on” - have a 12v for about 3 second and then ear the relay stop it
2 – when switch is fuel “res” – same

I checked the Fuel pump connector – while motor do run:

1 – switch is “on” - have a 12v for about several second and then it’s gone – 0 volts – engine lack of fuel
2 – switch is “res” – 12v always – the engine can run

Relay – I replace my relay from my 99 – and all is same – so its not the relay

When the fuel is bellow 12litter (empty) - the red light don’t turn on

What should I check next ?

 

[jfeagins]

Is the little light in the dash working when you turn on the key, and before you start the bike?

 

[uri gal]

do you mean the red fuel light?
no - it should work?

not worked at the 85 (even before that issue)
and not on my 99 - when I have no issue at all

 

[blaxmax]

Hello all

I guess owning two vmax’s that mean more posts LOL

The issue with the fuel pump on my 85– its seems to have no fuel from the pump when the bike is with a full tank of fuel

I tried to read other posts but its won’t help

I can tell that:

I checked the Fuel pump connector – when I switch the ignition to “on” while motor not started:

1 – when switch fuel is “on” - have a 12v for about 3 second and then ear the relay stop it
2 – when switch is fuel “res” – same

I checked the Fuel pump connector – while motor do run:

1 – switch is “on” - have a 12v for about several second and then it’s gone – 0 volts – engine lack of fuel
2 – switch is “res” – 12v always – the engine can run

Relay – I replace my relay from my 99 – and all is same – so its not the relay

When the fuel is bellow 12litter (empty) - the red light don’t turn on

What should I check next ?

Ask if they ship international and if they won't contact me and I will get it and ship it to you. It has a lifetime guarantee and is a great price. You can easily change the holding brackets outs.
http://www.ebay.com/itm/261965637189?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

OK they do ship international.

 

[jfeagins]

Ask if they ship international and if they won't contact me and I will get it and ship it to you. It has a lifetime guarantee and is a great price. You can easily change the holding brackets outs.
http://www.ebay.com/itm/261965637189?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

OK they do ship international.

"2 – switch is “res” – 12v always – the engine can run"

Blax, quoted above, he says his pump works - when on reserve and the bike is running. Shouldn't be a fuel pump problem. And since his relay has been swapped out from a known working bike...............that leaves the reserve circuit wiring...IMO..leastways.

Getting on my bike & riding w/o any problems, to speak of, over the last several years has gotten me to forget how some stuff "should" work when working properly - I just take all that stuff for granted. Anyway, I thought that the fuel warning light was supposed to come on when first turning the key ON, then go out as the bike is started, to show that the bulb is functioning correctly. Is this not the case?

 

[blaxmax]

"2 – switch is “res” – 12v always – the engine can run"

Blax, quoted above, he says his pump works - when on reserve and the bike is running. Shouldn't be a fuel pump problem. And since his relay has been swapped out from a known working bike...............that leaves the reserve circuit wiring...IMO..leastways.

Getting on my bike & riding w/o any problems, to speak of, over the last several years has gotten me to forget how some stuff "should" work when working properly - I just take all that stuff for granted. Anyway, I thought that the fuel warning light was supposed to come on when first turning the key ON, then go out as the bike is started, to show that the bulb is functioning correctly. Is this not the case?

I hope it is ok that I send it to someone trying to help and could be used in the future also .It is a great price with a great guarantee. I read what he said and comprehend, just trying to help.

 

[uri gal]

Blaxmax - thanks for the help ! Really.

The pump dose work properly on res and the bike run great.

In the first start only the oil light turn on (on the 85 with the pump problem).. the fuel not.
I cheched the bulb itself -its good.

I checked again on my 99 and both turn on..

 

[uri gal]

I think that the fact that the light of the fuel dont turn on on first start (like the oil do ) indicate the problem. So what sould i check next ?

 

[blaxmax]

Here is a wire diagram showing the green wire from the fuel light going to the relay and fuel level sensor. I would check your right side switch and there are connections that are probably needed cleaning. I will send you a thread on it.

http://www.morleysmuscle.com/download_file/view_inline/36/

 

[uri gal]

I play some with the connectors of the diods, sender, and relay...

now the pump do get +12v on "on" passion - even when the bike is started and run (I did not ride it, just on garage for several mints .. so I don't know if it will stay like thay)

anyway - at first start - the fuel light still don't turn on - while the oil light is do.

the tank is full so I don't know if the sender working or not

I did a check - I bridge the sender connector - and the fuel light turn on - that's mean all the connection is working properly

can someone please tell if in the 85 models the fuel should turn on in first start ? ( I know that in my 99 both turn on )

 

[blaxmax]

On my '85 the fuel light does not light up on start but I believe it is supposed to.It also does not work for reserve and so my reserve does not work either.
I plug the bulb in a different socket and the bulb works.

 

[uri gal]

Intresting...
I do know that the tach unit is diffrent from 85 to 99.. the 85 have red hernes connector while in the 99 the same connector is black.. also the color of the wires is not the same.
I guss i should drive and drive.. and if i can make the way back home - thats mean its work....and if not... LOL

 

[jfeagins]

There is something wrong in your fuel light circuit. You should have a red light illuminate when the key is ON, and the run switch is set to RUN, before you start your bike. Make sure your neutral light is ON, and try pulling in your clutch lever. Then push the start switch. If your light still does not come on.......there is something wrong.

If the bulb & it's socket check out OK, then trace it's green wire back and check for bad connections.

 

[uri gal]

Problem solved - some bad and old connection… now all working properly.

BUT – for the next generation of riders that may ask:

on 85-89 models, the fuel light should NOT TURN when first start for indication! Only the oil do

At 90+ - both fuel and oil turn ON on first start.

At 85-89 circuit: very simple circuit… from fuel bulb to sender to fuel pump relay to pump itself

At 90+ models – its goes thru also the Diode.. it’s a different circuit design.

That’s one problem off for my old max J

Thanks for all for the help and the info

Uri

 

[blaxmax]

Thanks for the info Uri gal. Like I said my fuel light has never lit up when I turn the key on.

 

[jfeagins]

The manual I have says it should. I must have gotten hold of a version of the manual meant for a newer than 85 Vmax. And after over 31 years of riding the ole' 85, I gotta confess, I never look at it's dash panel when starting. I usually just wait until I hear the end of the fuel pump cycling, then hit start.

At least you found the bad connections & got your bike sorted.

 

[jfeagins]

I swung by the house during lunch today & pulled out my old original paperback copy of the VMX12N owners manual. The page dealing with the dash lights is written completely different than the electronic version of VMX12M I have available on this computer. It does say that the only time you will see that low fuel light is when it kicks on to tell you the fuel is low. I will note, additionally, that on the 85's, the oil light will test to ON only while you are actually hitting the starter button & before the engine fires over, and not when simply sitting there with the key ON & the bike in neutral, like I thought it was. I even took the time to verify (to myself) that this was the case by firing it up and paying close attention to the dash - for the first time in many, many years.

I live & learned something about my old faithful 85 scooter again today.

 

[PMaxx]

With my 2000, if I try to hit the starter button while in gear with no clutch then the oil and fuel light will light up. Pretty sure they don't light up during a neutral start.