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Grr. Fuel pump / fuel issue again...


Andre1150

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Sometimes things seem to just keep showing up in your life -- and here again I'm posting because I just need a friendly ear or perhaps some understanding on what's becoming a long running issue with my 2004 1150RT. I love this bike, but last time I was at the dealer, he asked when I was going to trade her in -- and I seem to be working on the bike more than riding it and perhaps it's time.

 

So, I apologize for getting on here and asking more questions.

 

I was riding along in 2nd gear, bikes been misfiring, but only on occasion.. when upon hard acceleration, the bike dies and engine quits going 45mph. All lights are on, RID is lit, warning lights are lit, ABS works and I coast to a stop. After getting the bike home, I check for spark on primary coils -- good. Secondary plugs --good. Pull the fuel filter hose (i externally mounted mine) and turned the bike on, no fuel pump noise, no fuel pressure. Check the fuse -- good. Check the relay by swapping horn relay -- good. Pull the tank and remove the pump and attach leads to the battery -- pump runs well.

 

I'm thinking it's wiring. I don't believe it's the HES because it's new and only has about 1000 miles on it.

 

Any further ideas?? thanks in advance.

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I had a similar issue on my previous RT right after service. The dealer has just barely plugged in the Quick Disconcect fuel lines on the right side. After a few miles it spit, sputtered, and died.

 

Sounds like you may have a different problem, but you might give it a quick check. It can be hard to get them fully connected.

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roger 04 rt

It sounds like either the ground wire or +12 wire doesn't make it from the relay, through the fuel tank connector, through the side plate to the fuel pump. You need to get a DVM or test light and follow the wires.

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thank you for responding.. but i took out the quick disconnects. on a long trip through utah, one slightly disconnected and left me stranded until i fiddled with it. When I moved the fuel filter outside the tank, I eliminated them from my bikes fueling path.

 

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It sounds like either the ground wire or +12 wire doesn't make it from the relay, through the fuel tank connector, through the side plate to the fuel pump. You need to get a DVM or test light and follow the wires.

 

I tested both sides of the connector.. working my way back through the loom...

 

do you think it might be the HES?

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It sounds like either the ground wire or +12 wire doesn't make it from the relay, through the fuel tank connector, through the side plate to the fuel pump. You need to get a DVM or test light and follow the wires.

 

I tested both sides of the connector.. working my way back through the loom...

 

do you think it might be the HES?

 

Morning FireKit

 

Possible, but that shouldn't effect the initial key-on 3 second fuel pump run.

 

Start at the #6 fuse, is it good & have continuity through it? Does fuse #6 have 12v going into it, through it, & out of it ??????

 

Then at the fuel pump relay socket-- does term 30 have 12V on it?

 

At pump relay does term 86 have key-on 12v ? If not then verify power from the ign switch-through kill switch-then to relay socket.

 

Then jump term 30 to term 87 at fuel pump relay socket -- pump should run. If it does then a good possibility that the Motronic isn't triggering fuel pump relay (possible HES or other Motronic control issue.

 

If pump won't run with relay socket term 30 jumped to 87 then recheck 12v power into relay socket (term 30) & check for terminal 87 having continuity to fuel pump (+).

 

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Start at the #6 fuse, is it good & have continuity through it? Does fuse #6 have 12v going into it, through it, & out of it ??????

 

YES

 

Then at the fuel pump relay socket-- does term 30 have 12V on it?

 

YES. on my relay, it's labeled 3-2 1-5 on the side. 3 connects through to 5 via a switch, 2 connects through to 1 which energizes the relay. I get power on 3, and switched power on I believe terminal 1.

 

basically, I think you want me to jumper the switch 3 to 5, to test if the motronic isn't signalling the relay to energize via 2-1 or 1-2.

 

At pump relay does term 86 have key-on 12v ?

 

Yes, but it's labeled 3 on this relay.

 

If not then verify power from the ign switch-through kill switch-then to relay socket.

 

Testing. RID turns on and off via kill switch.

 

Then jump term 30 to term 87 at fuel pump relay socket -- pump should run. If it does then a good possibility that the Motronic isn't triggering fuel pump relay (possible HES or other Motronic control issue.

 

Fuel pump runs with terminals 3 and 5 jumpered.

 

Let me check the HES, and is there any way to test the motronic?

I'm hooking up my GS911 to see if there's anything as well.

 

Thank you again.

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roger 04 rt

Based on what you describe it sounds like something in the Motronic activation chain. It does not sound like an hes.

 

Since the fuel pump runs with its relay jumpered, the signal that controls the relay isn't being sent by the Motronic. The usual reason for that is a sidestand-switch, gearbox neutral switch or failed Motronic relay. Is the RID fully on and indicating fuel and neutral and is your green neutral light on?

 

A quick way to check all that is to:

--remove the Motronic relay

--install the fuel pump relay

--put the bike in neutral for safety

--turn on the key

--insert a jumper across the Motronic contacts (don't short its control coil)

--when you insert the Motronic jumper the fuel pump should run for 2 seconds like normal key on

 

Pull in your clutch (in case the neutral switch has failed), the bike should start if the fuel pump ran.

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Key on, the gs911 communicates with the Motronic, no error codes, except for HES, but that's because engine is not running.

 

 

 

 

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--insert a jumper across the Motronic contacts (don't short its control coil)

--when you insert the Motronic jumper the fuel pump should run for 2 seconds like normal key on

 

You mean the motronic Relay contacts, not the #1 terminal on the motronic itself (the fuel pump connection) because it looks like the motronic relay connects to 33 (per a diagram)

 

Thanks again for your help, sorry if I have questions.

 

 

 

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Ok, final update before I head to bed -- I think I've narrowed it down to either the motronic itself, or a short somewhere.

 

Plugging the GS911 in, I can run the HES sensor test, and rotating the crankshaft with a socket wrench, can get the 911 to show me the sensor turning on or off for both top and bottom sensor -- it's a new HES so I was glad that at least I'm getting signal to the GS911.

 

The hexcode PC software detects the HES just fine.

 

Next in the testing section of the PC GS911 software there's a test to fire the fuel pump -- when I ran this test, I got nothing.. doesn't the GS911 tell the motronic to fire the pump?? I think so.

 

anyway.. i'm beat.. tomorrow will be better.

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roger 04 rt

The GS-911 tells the Motronic to turn on the fuel pump. The Motronic does that by by grounding the control side of the relay coil.

 

The wire that it uses to ground the control coil is a blue/brown wire that goes from pin 16 of the Motronic to pin 1 of the fuel pump relay. +12v goes to the other side of the control coil on the fpr on pin 2 with a green/red wire connected to the kill switch.

 

So it may be that there's no +12, or the ground signal isn't coming from the Motronic.

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  • 2 weeks later...

Ok, new ECU arrived in the mail and I hooked it up. As before with the old ECU, the fuel level warning light comes on (no tank attached, fuel pump is outside the tank), RID comes on, lights come on -- electrially the bike seems fine. Swapped the motronic and the same thing, all lights, warnings, RID comes on fine.

 

Only the fuel pump does not run when key is turned.

 

I'm looking at wiring harnesses online and I'm trying to find a harness that will fit my bike because that's my next step -- cure the long ago wiring short that fried a bit of the main harness, although the bike has run fine for three years despite that)

 

The Motronic connector on a similar wiring harness looks different than mine. On mine there are a full complement of pins in the connector with only four missing in a row on the upper row, and one on the bottom left (harness side to the left)

 

on the harness i'm looking at there are more pins missing in the connector -- meaning i'm missing some sensors or something. i suppose i have to find a motronic connector/harness that is close/perfect to mine to work correctly, right?>

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The Motronic connector on a similar wiring harness looks different than mine. On mine there are a full complement of pins in the connector with only four missing in a row on the upper row, and one on the bottom left (harness side to the left)

 

on the harness i'm looking at there are more pins missing in the connector -- meaning i'm missing some sensors or something. i suppose i have to find a motronic connector/harness that is close/perfect to mine to work correctly, right?>

 

Afternoon FireKit

 

It has to match close enough to have all the inputs & outputs where they belong.

 

If your bike is a twin spark then your new harness needs to have all those wires & terminals to function properly.

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Have you actually replaced fuse #6?

 

Don't simply check it, try replacing it, especially if its an original BMW ceramic fuse.

 

Then try again.....

 

 

 

 

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Thanks Phil, I'll replace the fuse just to take that out of the loop.

 

However, if it was a bad wiring connection to the fuel pump wouldn't my GS911 show something regarding the pump?

 

 

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However, if it was a bad wiring connection to the fuel pump wouldn't my GS911 show something regarding the pump?

 

 

 

Morning FireKit

 

NO.

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