Any ideas why it just quit??

'99 R1100S, ABS with 16K miles, a new clutch, Af-Xied, 14.5v voltage reg, LED high beam, in-tank fuel tubing.

Took it out Sat for a ride, second since the clutch install. We got 12 miles, ran really well, pulled up to a red light, put it in neutral, sat back, looked around and it just quit like I hit the kill switch. Trucked it back home.

It's not out of gas, has good spark, I can hear the fuel pump run to pressure-up and stop. The engine will run for a half second by squirting a few drops of fuel in the injector port. All fuses and relays seem to be good. NO spray from the injectors. There seemed to be a VERY tiny bit of spray the first few times I tested/cranked it with the injector hanging out. NONE now.

I tried it without the AF-Xied, no joy. Tried old injectors. Same thing.

Everything else, lights, starter, horn, seems to be working properly, battery is all charged up.

ECU or Motronic?? Not sure what else it could be and am totally unfamiliar with either. Any way to test besides replacing?? What could cause a failure besides 18 years??

Lowndes

I don't know the specifics of the Motronic but typically in fuel injection systems, the initial 2 second fuel pump operation is to 'prime' the system in preparation for starting and running. That initial pump pulse stops once it runs. Further pump operation depends on the motronic getting a signal that the engine is cranking or running. That signal usually comes from the ignition system - hall effect in the case of most engines. If the HES failed, you would not have spark. Are you sure the spark is continuous while cranking and not just one good spark at 'key on'. I'm not fully conversant with Motronic but I'm guessing others on here can clarify.

'99 R1100S, ABS with 16K miles, a new clutch, Af-Xied, 14.5v voltage reg, LED high beam, in-tank fuel tubing.

 

Took it out Sat for a ride, second since the clutch install. We got 12 miles, ran really well, pulled up to a red light, put it in neutral, sat back, looked around and it just quit like I hit the kill switch. Trucked it back home.

 

It's not out of gas, has good spark, I can hear the fuel pump run to pressure-up and stop. The engine will run for a half second by squirting a few drops of fuel in the injector port. All fuses and relays seem to be good. NO spray from the injectors. There seemed to be a VERY tiny bit of spray the first few times I tested/cranked it with the injector hanging out. NONE now.

 

I tried it without the AF-Xied, no joy. Tried old injectors. Same thing.

 

Everything else, lights, starter, horn, seems to be working properly, battery is all charged up.

 

ECU or Motronic?? Not sure what else it could be and am totally unfamiliar with either. Any way to test besides replacing?? What could cause a failure besides 18 years??

 

 

Morning Lowndes

You should probably do a fuel return hose flow test next-- it sounds a lot like you blew a high pressure hose off inside the fuel tank.

The fuel pump runs upon key-on per Motronic command, not until the fuel rail is pressurized, so pump will run that couple of seconds regardless of pressure build up.

Just remove the fuel return hose connection then plug off hose coming from front of bike then place hose coming from rear of bike into a container. Then turn key on-- You need to see a pencil sized stream of fuel coming from the return hose for that couple of seconds after key-on, then see it continually during engine cranking.

Like DR said, a blown in-tank hose. Confirm that it is (or isn't) with the return-flow test, which is 2 liters per minute normally.

THANK YOU, Dr. Dirtrider and Roger04RT!!

As much trouble as getting to the pump and filter is, it sure sounds better than a new Motronic!!

I had all that apart and replaced the "U" hoses and sock filter, probably didn't tighten a clamp enough.

Fuel return test this Sat.

THANKS AGAIN,

Lowndes

Before opening up the tank, check for spark too. If there is no spark and no fuel squirt, it's the HES plate. If you do have spark, follow the fuel lines as suggested above.

Dan.

Before opening up the tank, check for spark too. If there is no spark and no fuel squirt, it's the HES plate. If you do have spark, follow the fuel lines as suggested above.

 

Dan.

Hey, Dan,

Oh, it's got spark. I jump started myself twice while looking at the spark on a test plug.

I think I answered my own question about what could it be besides 18 years old: some knucklehead forgetting to tighten the clamps on the internal fuel lines might be the problem.

Lowndes

Morning Lowndes

Another thought-- any chance that someone has installed quick disconnect fuel line connectors? If so then make darn sure that the pressure line quick disconnect is pushed (snapped) COMPLETELY together.--(verify that before removing fuel tank)

Those quick disconnects have internal safety valves so if not completely snapped together they will shut off the fuel flow.

Morning Lowndes

 

Another thought-- any chance that someone has installed quick disconnect fuel line connectors? If so then make darn sure that the pressure line quick disconnect is pushed (snapped) COMPLETELY together.--(verify that before removing fuel tank)

 

Those quick disconnects have internal safety valves so if not completely snapped together they will shut off the fuel flow.

No quick disconnects, Dr. Dirtrider!! I've considered it, even put them in the "cart", but have not ordered, probably should as many times as I've needed them. It's just the same total lack of any sense that caused the fuel line clamp to not be tightened, to begin with!!

But, Thanks!!

Lowndes

Morning Lowndes

 

Another thought-- any chance that someone has installed quick disconnect fuel line connectors? If so then make darn sure that the pressure line quick disconnect is pushed (snapped) COMPLETELY together.--(verify that before removing fuel tank)

 

Those quick disconnects have internal safety valves so if not completely snapped together they will shut off the fuel flow.

No quick disconnects, Dr. Dirtrider!! I've considered it, even put them in the "cart", but have not ordered, probably should as many times as I've needed them. It's just the same total lack of any sense that caused the fuel line clamp to not be tightened, to begin with!!

But, Thanks, Dr.!!

Lowndes

'99 R1100S, ABS with 16K miles

Such a low mileage bike must have sat around a lot, unused.

It happened that I worked on a 2002 F650GS, ~ 8k kms, looked like new, but it did not start.

Because the bike sat for that long, the fuel pump somehow rusted and did not spin, so no fuel pressure.

The thing I would suspect on your bike is the fuel pump; you should get a replacement pump, does not have to be OEM, any cheap pump that produces 4 bar gas pressure should do, see if that solves it. Then replace with an appropriate pump, that fits the RT.

Dan.

'99 R1100S, ABS with 16K miles

 

Such a low mileage bike must have sat around a lot, unused.

It happened that I worked on a 2002 F650GS, ~ 8k kms, looked like new, but it did not start.

 

Because the bike sat for that long, the fuel pump somehow rusted and did not spin, so no fuel pressure.

 

The thing I would suspect on your bike is the fuel pump; you should get a replacement pump, does not have to be OEM, any cheap pump that produces 4 bar gas pressure should do, see if that solves it. Then replace with an appropriate pump, that fits the RT.

 

Morning Dan

He can hear the fuel pump running.

Thanks, Dan, but I wasn't POSITIVE it was the pump and not something else running, so I pulled the tank and connected the pump leads to a batt. The pump spins just fine. I do wish it was something else like a bad pump to blame besides myself. I'll find out tomorrow evening, but I'd bet the house that Dr. Dirtrider is correct with his first diagnosis.

Lowndes

Well, Dr. Dirtrider was exactly correct with his first diagnosis. The "U" hose popped off the outlet tube inside the tank. Knucklehead here didn't get it tightened down quite well enough. What a pain.

THANKS, Dr.!!

Lowndes

Glad you got it fixed. Out of curiosity, why a new clutch with so little miles?