Safe to assume bad fuel pump? >>

[BalancePoint]

Bike has been quitting intermittently. Again today, but no re-start happening. Have power to the connector for the fuel tank. Ignition switch activates the voltage at the connector, and to the other side of the connector itself. no amount of wiggling the wire up to the fuel pump cover gets it to come on. No crazy tach needle, didn't check for spark, but definitely no fuel pump despite presence of juice at least to tank itself. Bike turns over fine.

 

1998 R1100R.

[smiller]

If you are saying that you're seeing the two-second fuel system pressurization pulse when you turn on the key, and you see it on the fuel pump side of the tank connector (power and ground), and no response from the pump then I'd say yeah, one has to seriously suspect the fuel pump at that point.

[BalancePoint]

If you are saying that you're seeing the two-second fuel system pressurization pulse when you turn on the key, and you see it on the fuel pump side of the tank connector (power and ground), and no response from the pump then I'd say yeah, one has to seriously suspect the fuel pump at that point.

 

After leaving the bike for a few hours, I tried it again. The pump started with the ignition, and the bike runs fine. Needless to say, my confidence is minimal. Is a bad fuel pump likely to run OK until it heats up to a point and then quits, or at this point is the more likely scenario a loose connection inside the tank?

[philbytx]

Get the bike hot again and see if it quits. While it is still warm, remove an injector and a plug lead. Turn on yr ignition and try to start it, trying the the injector first (don't put the plug in yet!!!). You should see spray from your injector. If you do, replace the injector and now try your ignition system. Put the plug on the lead and crank it, you should see it spark. If no spark and no spray, dollars to donuts its your HES. If you have a spark and no spray and you didn't hear the fuel pump, as Seth said, its most likely fuel pump related (pump, connectors, wiring etc).

 

BTDT.....

[smiller]

A primary thing to observe when the problem exists is whether you hear the pump operate for a few seconds when the key is first turned on. If you don't hear that then look to the pump or pump circuit (as the HES has nothing to do with the initial pressurization pulse.) If you do hear the pressurization sequence then check for pressure, blockage, proper tank venting, possible HES problem, etc.

[BalancePoint]

Get the bike hot again and see if it quits. While it is still warm, remove an injector and a plug lead. Turn on yr ignition and try to start it, trying the the injector first (don't put the plug in yet!!!). You should see spray from your injector. If you do, replace the injector and now try your ignition system. Put the plug on the lead and crank it, you should see it spark. If no spark and no spray, dollars to donuts its your HES. If you have a spark and no spray and you didn't hear the fuel pump, as Seth said, its most likely fuel pump related (pump, connectors, wiring etc).

 

 

Are you saying that a bad HES will disable the fuel pump?

[smiller]

Are you saying that a bad HES will disable the fuel pump?

After engine start the ECU looks for pulses from the HES to ensure that the engine is running and that it should continue to supply power to the fuel pump, so if the pulses end so does the power to the pump. But the 2-second initial pressurization is controlled only by the ECU (not the HES since the engine isn't spinning at that point) so the initial pulse (or lack thereof) can be a helpful diagnostic tool in locating the problem to one circuit or another.

[BalancePoint]

Are you saying that a bad HES will disable the fuel pump?

After engine start the ECU looks for pulses from the HES to ensure that the engine is running and that it should continue to supply power to the fuel pump, so if the pulses end so does the power to the pump. But the 2-second initial pressurization is controlled only by the ECU (not the HES since the engine isn't spinning at that point) so the initial pulse (or lack thereof) can be a helpful diagnostic tool in locating the problem to one circuit or another.

 

So during the time that my fuel pump would not run when the key was turned on, despite the presence of voltage on the pump side of the connector is not related to the HES?

[smiller]

So during the time that my fuel pump would not run when the key was turned on, despite the presence of voltage on the pump side of the connector is not related to the HES?

If at any time you see voltage on the pump side of the connector and the pump isn't running then you likely have a problem with the pump (all assuming that you're testing the correct wires of course.) But yes, the HES does not come into play at all during the initial key-on pulse. If the initial pulse isn't occurring then the HES is not the problem.

[philbytx]

As Seth said....if you have an initial fuel pump FI system pressurization "whine" when you turn on the ignition and THEN the engine fails to start, it could well be your HES. That's when you check the Injector nozzle for spray and the plug for spark.

 

If your bike fails again, turn off the ignition and wait a while then turn it on again, listening for the tell tale whine of the fuel pump pressurizing the system.

If the pump runs but the bike doesn't then its, dollars to donuts, your HES. If your pump does NOT run, then it may well be a wiring loom issue.....some of the R's had too tight zip ties around the headstock area, causing fraying.

 

I just went through the whole HES and wiring issues on my 2000 R. I replaced the HES and I also checked the wiring runs and re-ziptied parts of the loom around the headstock. Some of mine was indeed rubbing through!

 

 

 

 

[BalancePoint]

So during the time that my fuel pump would not run when the key was turned on, despite the presence of voltage on the pump side of the connector is not related to the HES?

If at any time you see voltage on the pump side of the connector and the pump isn't running then you likely have a problem with the pump (all assuming that you're testing the correct wires of course.) But yes, the HES does not come into play at all during the initial key-on pulse. If the initial pulse isn't occurring then the HES is not the problem.

 

I had voltage on all the wires, Key on- voltage, key off, none, key on, voltage. Re-connect connector- key on, no pump noise. 2 1/2 hours later, key on- pump noise: joy. Can a bad pump cool off and run OK again? As an aside, dry as toast here with low humidity, HES less than a year old. Not that that matters much.

[smiller]

Can a bad pump cool off and run OK again?

Yes. Fuel pumps are generally pretty reliable but over the years I have had them fail on me in just about any way you can imagine including no output, low output, and intermittent failure based on temperature. While oilhead fuel pumps are not known for being particularly troublesome anything is possible.

 

You are on the right track in checking for power at the pump if it's not running when it should. If there's no power when there should be there's a host of things to check, but if power is present and no pump run then there's not too many other things it can be. I would advise you to verify that you were looking at the right wires by noting whether the power drops a few seconds after key on. If it does then you're where you should be.

 

 

[Dave C.]

My fuel pump did what it sounds like yours is doing. When you turn the key if you do not hear the whine of the pump replace it. I did that and have not had an issue with the fuel pump again.

 

Dave

[BalancePoint]

If you are saying that you're seeing the two-second fuel system pressurization pulse when you turn on the key, and you see it on the fuel pump side of the tank connector (power and ground), and no response from the pump then I'd say yeah, one has to seriously suspect the fuel pump at that point.

 

I get about a second or so of pulse on the tank side of the connector at about 11.5 volts, and then it drops to maybe 5 volts for another second or so before tailing off to less than a volt. Pump doesn't react at all.

[Ken H.]

I get about a second or so of pulse on the tank side of the connector at about 11.5 volts, and then it drops to maybe 5 volts for another second or so before tailing off to less than a volt. Pump doesn't react at all.

With or without the pump side connected?

[BalancePoint]

I get about a second or so of pulse on the tank side of the connector at about 11.5 volts, and then it drops to maybe 5 volts for another second or so before tailing off to less than a volt. Pump doesn't react at all.

With or without the pump side connected?

 

With the pump side connected.

[smiller]

Power to the pump is controlled by a relay so the on/off should be pretty clean... try disconnecting the pump (open up the connector) and look again to see if you get a clean (voltage constant) pulse.

 

If the voltage is constant with no pump connected but low with the pump connected then either your pump is in bad shape/locking up and drawing a lot of current, or you have a bad connection somewhere in the pump power supply circuit (including the relay)... either condition could cause a voltage drop. If this is the case try supplying power directly to the pump with jumper leads. If it still doesn't run properly then the pump is bad, and if it does then you have a poor connection somewhere in the pump power supply circuit.

 

[BalancePoint]

Bike has been quitting intermittently. Again today, but no re-start happening. Have power to the connector for the fuel tank. Ignition switch activates the voltage at the connector, and to the other side of the connector itself. no amount of wiggling the wire up to the fuel pump cover gets it to come on. No crazy tach needle, didn't check for spark, but definitely no fuel pump despite presence of juice at least to tank itself. Bike turns over fine.

 

1998 R1100R.

 

I pulled the tank and fuel pump/filter assembly this evening and applied power directly to the pump. Spooled right up. I checked the continuity between the 3 wires in the harness and the connectors to the pump itself and to the fuel level arm assembly. I have continuity to the fuel level arm, and to the leads that attach to the fuel pump from the soldered points inside the mounting plate, but somewhere ( I think in the plastic part that passes the three wires through the plate and terminates in an odd soldered arrangement- and possibly a switch of some kind?) I lose continuity between the harness connnector and the attachment points on the fuel pump. The entire assembly looks pretty worse-for-wear. The outside of the mounting plate is stamped: BMW 1614 2 306 636 R, and I can't find that part number at Max BMW or A&S, the closest I find is 1614 2 306 640, a "petrol gauge" with an illustration that matches what I have.

 

Superceded part number? Best to replace or try and do something with that seemingly impregnable plastic pass through into the tank?

 

I really need this entire thing, short of the filter and pump:

[Ken H.]

Oh, if you think the wire is broken where it passes through the plate, I’m not sure that’s repairable. I don’t think you’d ever get it to not leak again.

 

I’d shop the salvage/breakers market for a new ass’y at this point if it was me.

 

 

There is no switch or such in there BTW, just the liquid tight pass through.