Fuel Reseve System

[biggo]

Hi All

My first post on here 

I have a 93 FJ1200.  The bike goes into reserve mode and cuts the engine off just after the low fuel warning light comes on.  The switch makes no differance at all.  The only way I can get her going again is to remove the seat and disconect the wiring loom to the fuel tank then she fires back into llife.  I have read that the reserve system cuts off 2 cylinders via the ignition system but am sure someone here will know the answer

Cheers  Phil

[airheadPete]

Oh goody, it's different, but almost the same to what I was going to ask. I've got a '92 CA model and am not having any problems, but: just how does that damned switch work? What does it do? I'm not getting any enlightenment from the books, so...? (All my other stuff is the old manual kind with seperate standpipes.) I'm certain someone will staighten me out...  just be gentle.

[movenon]

Can I chime in? Inquiring minds and all. I have 1990 FJ. As I understand it,  when it go's into reserve it will cut out 2 cyl, "simulating" a miss fire. I am also under the impression if I disconnect the electrical connector under the tank that all will be well. Of course now it will run until you are totally out of fuel. Perhaps a small switch installed next the reserve rocker switch location to disrupt the signal instead of pulling the connector under the tank might be handy. Not going to give you any more fuel but let you run normally until you get to a refueling point.

I do not know the exact nature or design of the sensor in the tank that trips the system or if it is adjustable. Anyone with a good explanation?
With an understanding of the in tank sensor I might have a better idea. More on that when I get a good understanding of the total system from someone with more knowledge than me. Perhaps sometime when the bike is down hard for maintenance I will have a look see into the mechanics of the system.

I have never had the "opportunity" to run my reserve switch as I stop often to refuel. Out in the Nevada area you best keep your tank in the top half. And to tell you the truth I am a bit leery of the system, as I was once burnt with a Yamaha with an electronic reserve fuel system. It went into reserve and at about 200 feet later the bike totally flamed out. Luckily I was in town and not out in the middle of no where with 50 miles or more to go before the next fuel stop.

[Arnie]

The "Reserve" system on the fuel pump bikes works like this:
When the variable resistor fuel level sensor indicates a certain resistance that the EMU considers "low", it cuts power to the fuel pump.  When you switch to "Reserve", power is restored to the pump.

The low fuel light works off this same sensor independently of the "reserve" switch system.

Disconnecting the 2 wire connector from the tank will disable all these systems, fuel meter, low fuel light, and "reserve" switch.  Then you'll have to watch the trip meter to know when you're almost out of fuel :-)
You should probably watch the trip meter anyhow.

It is pretty easy for the sensor to become UN calibrated and cause the fuel meter, low fuel light, and "reserve" switch all not work as intended.  
Search fuel level sensor here and you should find many posts about how to re-calibrate.

Cheers,
Arnie

[ribbert]

Hi All

My first post on here 

I have a 93 FJ1200.  The bike goes into reserve mode and cuts the engine off just after the low fuel warning light comes on.  The switch makes no differance at all.  The only way I can get her going again is to remove the seat and disconect the wiring loom to the fuel tank then she fires back into llife.  I have read that the reserve system cuts off 2 cylinders via the ignition system but am sure someone here will know the answer

Cheers  Phil

Hi Phil and welcome.

I notice Arnie's explained the reserve function in detail, however, when switching to reserve after the engine begins to splutter it takes a bit of time, maybe 5 - 10 seconds, before it starts to run sweet again.

The first time this happens you think the switch is doing nothing because there is no immediate change. Next time wait and see what happens 10 secs. after you have flipped the reserve switch.

What you may be doing with the seat off / disconnecting the terminal thing is in fact just giving it that time.

Noel

[93fj1200]

Hi All

My first post on here 

I have a 93 FJ1200.  The bike goes into reserve mode and cuts the engine off just after the low fuel warning light comes on.  The switch makes no differance at all.  The only way I can get her going again is to remove the seat and disconect the wiring loom to the fuel tank then she fires back into llife.  I have read that the reserve system cuts off 2 cylinders via the ignition system but am sure someone here will know the answer

Cheers  Phil

Hi Phil, welcome.  I have a 93 as well.  When I am getting low on gas, first my light comes on and I keep driving about 15-30kms until the bike begins to sputter, then I switch to reserve and it almost immediately starts running perfectly again. (only a few seconds). Afterwards, I have driven up to 50kms without running out.  When I have thought I must be just running on fumes, I fill up and the most that I have had to put in is 22 liters so there is still 2 liters left in the tank.  The bike has been running like that throughout my travels.  I had one incident where I switched the reserve switch and it would not run for about 2-3 minutes, then off I went again for another 5 minutes before it did it again.  I filled up afterwards and never had the problem again.  My fuel pump went a few weeks ago and I had noticed that there is a lot more vibration when the fuel pump is not working  very well or disconnected or by-passed.  Keeping the tank full until my new pump gets down here.  Have fun on that bike, they are great.
Greg

[Arnie]

93FJ1200,

Unless you've had a custom tank fitted to your bike, the total volume INCLUDING the fake reserve is 22L. You might get 100 or 200 ml more in there if you're careful, but that's it.

I stuffed up with my reserve switch one time and didn't get the cough, cough running out of fuel signal till I'd gone 400kms., and the bike died.  I pushed to the servo and put 22L in to the rim of my '91.  Just sayin......

Arnie

[movenon]

Thank you for the explanations. I guess next summer under controlled conditions I will try it out.  

[movenon]

I did a search as recommended and here's a link for more information.  http://www.fjowners.com/index.php?topic=6924.0   Next spring I will pull my sensor out and inspect. I might add that under the tank there is a small fuel filter. I usually change mine every spring.  One of the best things about owning an FJ is the knowledge base on this forum. TNX again.

[SlowOldGuy]

How do you have a '93 with a fuel light? 
Do they not have ABS?  My '93 has no low fuel light because the ABS light is in its place.

DavidR.

[hein]

   I don't know about the US. market but in Canada the 93 was available with or without ABS.

Hein.

[biggo]

How do you have a '93 with a fuel light? 
Do they not have ABS?  My '93 has no low fuel light because the ABS light is in its place.

DavidR.

Hi Mine is non ABS so I guess that is the differance. ABS was an option down here and there are some around but the majority seem to be without from what I have seen

[SlowOldGuy]

OK, that explains it. 
In the US, the '93 was only available with ABS.

Thanks,
DavidR.

[93fj1200]

93FJ1200,

Unless you've had a custom tank fitted to your bike, the total volume INCLUDING the fake reserve is 22L. You might get 100 or 200 ml more in there if you're careful, but that's it.

I stuffed up with my reserve switch one time and didn't get the cough, cough running out of fuel signal till I'd gone 400kms., and the bike died.  I pushed to the servo and put 22L in to the rim of my '91.  Just sayin......

Arnie

ok, metric nazi Arnie, just saying (haha)¨....... being from Canada and not used to American gallons used here in Panama, maybe my metric conversion is not so good, I put in 4.5 U.S. gallons (17.03435301 liters) and not the 20.45741346 liters or 4.5 U.K. gallons I had in my mind.

Anyway, on another subject, I replaced by fried fuel pump with one from a 2008 Yamaha Venture Royal Star from E-Bay for about $40 with shipping down to Panama.  Bolted in perfectly and exactly the same electrical connector.  Runs and starts perfectly and no more vibration either.  A lot cheaper alternative than trying to buy a genuine 20 year old fuel pump and a lot more reliable.

Greg (93fj1200)

[Arnie]

93FJ1200 said, "being from Canada and not used to American gallons used here in Panama, maybe my metric conversion is not so good, I put in 4.5 U.S. gallons (17.03435301 liters) and not the 20.45741346 liters or 4.5 U.K. gallons I had in my mind."

Does Canada use UK gallons?  My recollection (not recent) is either US gallons or Liters, at least in Windsor.

BTW  Don't let your conversion difficulties force you to walk :-)

Arnie