NewBlue Posted March 23, 2011 Share Posted March 23, 2011 Things really went south at post #10 There is still confusion as to why no pump with bypass until he used the acc. outlet. I would think the fpc controls the pump through the ground side, maybe something there, no idea. Probably because the ZFE may turn the power off to the fuel pump if the voltage drops below a certain threshold.. since a pump run on too low voltage will draw LOTS more current.. the accessory outlet probably doesn't have that restriction. So BMW's logic is if you're trying to start the bike with battery voltage less then ideal let's keep the heated gear on and cut the fuel pump to save power so the starter can spin. Way to go Fritz Link to comment
NewBlue Posted March 23, 2011 Share Posted March 23, 2011 Unfortunately we have no way to know for sure what went on here. With him not checking the power to the FPC as he used that power feed for initial jumper power to the pump we just don’t know if it was shut down by the PCM or was actually powering the pump but the pump was stuck from sitting. The thing that has me concerned is he couldn’t EVER hear the pump run at key-on even at 12.4 volts or when jumping from the other bike or even his car. He also couldn’t verify the pump would keep running while cranking even when jumpered from another bike. I’m not convinced this was just a low battery issue through the whole process. Might have been a low battery that started it all in motion but there was definitely something else going on there. Rather poor follow through on the testing sure didn’t help the situation. I think he hit the perfect storm, how it got there, don't know and probibly never will. Link to comment
NewBlue Posted March 23, 2011 Share Posted March 23, 2011 All great comments. This is how I learn stuff for the next time! I must say, drswift, you have a good attitude. You took a bad situation and turned it into a learning experience. Link to comment
drswift Posted March 25, 2011 Author Share Posted March 25, 2011 So far so good. More storms keep me out of the garage for a day. Put in new battery today after keeping it on the charger overnight and it fired right up - no hesitation. I will try again tomorrow when I have more time to do multiple starts. If the FPC acts up I'd like to have it happen again close to home. ITM - I ordered a jumper from Burnsmoto just to have for long trips. Link to comment
I812 Posted March 25, 2011 Share Posted March 25, 2011 I too ordered the jumper. Just because. Link to comment
I812 Posted March 26, 2011 Share Posted March 26, 2011 Next move is to monitor the FPC (fuel pump controller) control circuit to see if it is being energized during engine cranking. If in doubt there jump the fuel pump directly to battery power as a test to see if will then start. In my last post I meant fuel pump controller. So I'm getting some juice, just not full time. How do I jump the fuel pump? Is there a thread that shows more about this? I searched with poor results. Link to comment
dirtrider Posted March 26, 2011 Share Posted March 26, 2011 Morning 1812 I can’t remember a specific thread offhand but there probably is something in the archives covering it if you search enough. If you go back to page (3) in this thread I posted a picture of how to jumper & get the pump running if stuck out on the road WITHOUT a pre-made-up –jumper harness. Just print that picture and carry it with you. If you make or have a pre-made up jumper harness then it is a simple plug-in between the fuel pump and accessory outlet. You can make a simple harness with a plug that fits your accessory outlet & a couple of feet of wire. Then you can cut the FPC wires just above the fuel pump (that is just part of the FPC so no bike wire harness damage), the just twist the wires together—make sure to get the polarity correct as shown. You will also need to carry a torx bit that fits the FPC screws as that has to be removed to access the pump connector under it (that torx bit is NOT part of your BMW tool kit) Added: In a pinch you can make a jumper from a Gerbings heated garment supply wire and plug, or your tire pump wire harness (if you carry an aftermarket electric pump) Link to comment
NewBlue Posted March 26, 2011 Share Posted March 26, 2011 Next move is to monitor the FPC (fuel pump controller) control circuit to see if it is being energized during engine cranking. If in doubt there jump the fuel pump directly to battery power as a test to see if will then start. In my last post I meant fuel pump controller. So I'm getting some juice, just not full time. How do I jump the fuel pump? Is there a thread that shows more about this? I searched with poor results. Check here, there are video's and links that can help you. http://www.hexcode.co.za/techinfo/electric-fuel-pump-controller Link to comment
mig Posted March 27, 2011 Share Posted March 27, 2011 here is the right link http://www.motorcycleinfo.co.uk/index.cfm?fa=contentGeneric.nvxszdkebklxuaer&pageId=428065 Link to comment
I812 Posted March 27, 2011 Share Posted March 27, 2011 Thanks everyone! I had no idea where the fuel pump was. Link to comment
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