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2005 R1200ST No Start After Tank Removal


Wanjman

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So I recently replaced my fuel pump and the bike was running fine. I decided to remove the tank to detail the bike and after reinstalling it will not start. The STRANGE part is, I have verified fuel pressure at the output side of the filter (40psi) and the bike starts and runs if I spray starter fluid into the intake? I pulled the injectors and I'm getting fuel pulses when I crank it....very odd. I even bypassed the fuel control module so I have 12vdc direct to the pump.

Any help would be appreciated 

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28 minutes ago, Wanjman said:

So I recently replaced my fuel pump and the bike was running fine. I decided to remove the tank to detail the bike and after reinstalling it will not start. The STRANGE part is, I have verified fuel pressure at the output side of the filter (40psi) and the bike starts and runs if I spray starter fluid into the intake? I pulled the injectors and I'm getting fuel pulses when I crank it....very odd. I even bypassed the fuel control module so I have 12vdc direct to the pump.

Any help would be appreciated 

Afternoon Wanjman

 

Are you absolutely sure that the pressure side hose quick disconnect is FULLY snaped together  (hold the trigger in until it is firmly all the way together then release the trigger).  If it isn't all the way together it won't open the internal check valves.

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Yes I have removed and rechecked this connection  several times, but thank you for your reply. I just removed both injectors, disconnected them from the hose, disconnected the feed line after the fuel filter and blew air through with no apparent obstruction. I'm thinking perhaps a problem with the fuel pressure regulator, that little distribution port that sits between the ABS module and the air box? I'm totally stumped how I could have 40 psi coming out of the filter, a clean path to the injectors and no fuel actually coming out the injectors.

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54 minutes ago, Wanjman said:

Yes I have removed and rechecked this connection  several times, but thank you for your reply. I just removed both injectors, disconnected them from the hose, disconnected the feed line after the fuel filter and blew air through with no apparent obstruction. I'm thinking perhaps a problem with the fuel pressure regulator, that little distribution port that sits between the ABS module and the air box? I'm totally stumped how I could have 40 psi coming out of the filter, a clean path to the injectors and no fuel actually coming out the injectors.

Evening  Wanjman

 

How much fuel volume do you have on the engine side of the fuel filter? 40 psi (deadheaded) doesn't mean much if you have no flow volume at that 40 psi.    40 psi is on the low side but it should at least try to start & run at that psi. 

 

Do you still have 40 psi (with fuel flow) at the fuel injector line right at one of the injectors?

 

You say you have injector spray with engine cranking but HOW MUCH do you really have. A little fuel spray looks like a lot when testing but it takes a LOT of spray to start & run the engine. Check all your engine sensors for being  properly plugged in. 

 

No chance of a pinched fuel hose under fuel tank??

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So I haven't checked fuel pressure  at the injectors but there doesn't seem to be any restriction between the fuel filter and the injectors and when I checked for a good spray at the injectors while cranking it quickly dissipated to nothing after 4 or 5 cycles...mind now that it was running perfectly fine prior to removing the tank and reinstalling it. 

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12 hours ago, Wanjman said:

So I haven't checked fuel pressure  at the injectors but there doesn't seem to be any restriction between the fuel filter and the injectors and when I checked for a good spray at the injectors while cranking it quickly dissipated to nothing after 4 or 5 cycles...mind now that it was running perfectly fine prior to removing the tank and reinstalling it. 

Morning  Wanjman

 

Difficult to tell over the internet if you have a basic fuel flow AT PERSSURE issue or you have an engine sensor issue causing the BMS-K to not give a long enough injector pulse width during cranking.

 

Probably the next test I would (personally) run is a fuel return line flow test. If you run the fuel pump you need to have a decent stream of fuel continually  returning to the fuel tank with the pump running. This tells you that your pump can make enough pressure to open the  regulator by-pass valve & return fuel to the tank & if you have return  fuel flow that tells you that it has enough fuel flow AT the regulated 3.5 bar pressure.   

 

If the above is OK then use a tee in the pressure line to see what the (system)  fuel pressure is with pump running & all the fuel system plumbed back to stock. (tells you if the fuel pressure regulator is working correctly). You would like to see 3.5 bar (50.7 psi) system pressure so your 40 psi is already on the low side.  

 

If you have close to 3.5 bar (50.7 psi) WITH return flow out of the return hose then look for something on the engine management side  like a sensor disconnected or ?????

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I had a similar weird situation just a month ago. I acquired a high mileage (91k miles) 2005 R1200st and performed an extensive going-through including removing the fuel tank. The bike actually ran fine before and never had an issue starting. However after getting the fuel tank back on I had a crank but no-start condition. I thought it might have been the notorious fuel pump electrical unit as the installed unit appeared to be original (and obviously old). I installed a brand new unit to eliminate this as a future point of failure but it did not help the no-start condition. It would just crank as if starved for fuel.

 

I had bought a gs-911 and it had been reporting no fault codes the entire time. I got the idea to use its output test to run the fuel pump activation which it did. I then tried to start the bike and it started up immediately :5210:. I suppose the fuel pump was not able to get primed somehow without running the gs-911 test. Maybe consider this possibility.

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12 hours ago, Rockreid said:

I had a similar weird situation just a month ago. I acquired a high mileage (91k miles) 2005 R1200st and performed an extensive going-through including removing the fuel tank. The bike actually ran fine before and never had an issue starting. However after getting the fuel tank back on I had a crank but no-start condition. I thought it might have been the notorious fuel pump electrical unit as the installed unit appeared to be original (and obviously old). I installed a brand new unit to eliminate this as a future point of failure but it did not help the no-start condition. It would just crank as if starved for fuel.

 

I had bought a gs-911 and it had been reporting no fault codes the entire time. I got the idea to use its output test to run the fuel pump activation which it did. I then tried to start the bike and it started up immediately :5210:. I suppose the fuel pump was not able to get primed somehow without running the gs-911 test. Maybe consider this possibility.

Morning  Rockreid

 

You need to go back & read the entire thread.   Wanjman is getting 40 psi fuel pressure at the filter outlet so that tells us the pump must be priming & running & producing pressure, plus he ran 12v directly to the pump (FPC by-pass)  so that is the same as running the GS-911 pump output test as far as pump priming goes.  

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So, if I wanted to permanently bypass the fuel control module, where can I tap 12v ignition only to power the fuel pump? Strangely enough I don't have 12v on any of the 3 wires that plug into the module. When I ran power directly from the battery it started and ran. I tried using the accessory plug but the ecu cuts the power after about 5 seconds due to the high current draw from the pump. Not sure why I don't have 12v going into the fuel pump control module, I thought the module reduced the power to pump to reduce return fuel pressure...

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1 hour ago, Wanjman said:

So, if I wanted to permanently bypass the fuel control module, where can I tap 12v ignition only to power the fuel pump? Strangely enough I don't have 12v on any of the 3 wires that plug into the module. When I ran power directly from the battery it started and ran. I tried using the accessory plug but the ecu cuts the power after about 5 seconds due to the high current draw from the pump. Not sure why I don't have 12v going into the fuel pump control module, I thought the module reduced the power to pump to reduce return fuel pressure...

Evening  Wanjman

 

The early 1200 bikes definitely don't have enough amp capacity on the accessory plug circuit to run the fuel pump. In fact I don't believe you will find any ignition-on circuit on that motorcycle that will directly handle the pump load at full output. 

 

You will need to go (fused)  battery-direct for12v B+ using  a power relay for pump control. For relay control you can probably use a (key-on) power source at the starter relay (usually the black/yellow wire at the starter relay).   I will have to check on that with my BMW wiring diagram for the 1200 ST) -- so look back here later (or just test the black/yellow wire at the starter relay for key-on 12v)

 

Now lets figure out WHY you are not getting pump run through the BMS-K  fueling computer?

 

The pump only runs for a couple of seconds at key-on then doesn't run again until engine cranking or running so did you test for 12v on the blue/green wire going into the FPC --RIGHT AT first KEY ON? Then checked again during engine cranking?

 

If no power then unplug the main harness into the FPC & check it again, the pump might be drawing too much power therefore tripping the BMS-K's internal circuit breaker.   

 

You might also try a battery disconnect for about 1/2 hour then a re-connect &  re-test for 12v (or engine start)  as the BMS-K might be locked out from all the fiddling.

 

Also verify the blue/green & blue/red wires are not somehow pinched & grounded under the fuel tank therefore tripping the BMS-K's internal circuit breaker. 

 

 

 

 

 

 

 

 

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Great information,  thank you. I will follow up with my results after the holiday. Will the blue/green wire going into the FPC provide enough current to bypass the FPC and power the pump direct?

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9 hours ago, Wanjman said:

Great information,  thank you. I will follow up with my results after the holiday. Will the blue/green wire going into the FPC provide enough current to bypass the FPC and power the pump direct?

Morning  Wanjman

 

Yes, blue/green (could be blue/yellow on some1200 bikes) has enough power to run pump as that is what runs the pump in OEM operation. The blue/red is the FPC control circuit. 

 

So on the FPC input side (top connector on FPC) the blue/green wire goes to the pumps B+ input yellow wire. The top  connector brown wire (-) goes to the pump (-) blue wire. 

 

If the (unplugged)  blue/green (could be blue/yellow on some1200 bikes) has 12v during a quick key-on test (or during engine cranking) but quits when trying to run the pump then that probably means the pump is drawing too many amps & tripping the pump's circuit protection.  If the blue/green (could be blue/yellow on some1200 bikes) doesn't have any power at key-on or during engine cranking then that usually means the BMS-K is locked out or the blue/green circuit is shorted to ground someplace.  

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