Fuel pump???

[Willie]

For awhile now my RT makes a strange noise when I first turn the key. I was told in the past that it might be from low fuel level or when turning the key fron the sidestand. It seems to do it more often now. Only does it if it's sat for an hour or so. If the fuel system is pressurized already. sounds normal. I just did a fuel drain and filter swap and still does it. Any ideas? Does it sounds like the pump might be starting to go out? Could this be a reason for surging? Thanks

[ShovelStrokeEd]

The strange noise is the fuel pump. It runs for 2 seconds every time the key is turned from off to on, or the kill switch is cycled. If it is really loud, it could be an indicator that the fuel pump is going bad or, in your case, you got a bad one.

 

There might be another noise coming from the brake booster pumps, I really can't remember as it has been some time since I had a bike with that system. Again, nothing to worry about unless it is unusually loud.

 

Nothing whatever to do with the side stand or surging.

[Ken H.]

Discribe the sound more please... Duration? "Sounds like"? Coming from where?

[Willie]

It is a different noise than the usual fuel pump wind and brakes doing the test. It runs in unison with the regular fuel pump noise, but it about twice as loud and almost has the sound that a small electric motor would make if you grabbed it with your hand and stopped it. Not the most encouraging sound when you turn the key, that's for sure. It doesn't always do it though. Like I said, sometimes if it sits for awhile it will do it, but if the fuel system is already pressurized, like if you have just previously turned the key, it won't sound like that. Also, it sounded OK when I fired it up and went to work and was leaving work today. I should have done a tune up on the bike when it was apart to do the fuel filter, but I wanted to see if the filter had anything to do with the noise and the way it runs. It really didn't do anything for either. I have a true love/hate relationship with the RT, that's certain. It always seems to be something going on with this bike to frustrate me, but that makes the rides all that much better when it is running good. Any more thoughts? I mentioned the sidestand thing because I was told before that the noise could be from turning the key on a low fuel level and that it might make a different noise when the pump runs. Did it nice and loud after topping her off last might while on the centerstand, so at least that idea is eliminated. Thanks for the help.

[Fugu]

Does it sounds like the pump might be starting to go out?

That would make noise all the time

 

Could this be a reason for surging?

 

I don't think so

 

You just did a filter swap and made sure all the connections in the tank were OK, so it should rule those out...

 

 

 

You sure it's the fuel pump making noise? Might you have low brake fluid or some air in the system that is making the servos make a racket? You're attributing the lack of it to the fuel system being pressurized, but maybe it's a brake thing.

 

Mileage?

[Willie]

22k. Just changed the brake fluid at the 18k tune up. Had the dealership hook the bike up to the computer to read any codes and part of that was a brake test. Everything came out OK.

[Ken H.]

Well I'd at this point I'd have to vote fuel pump on the way out too then.

[Willie]

SWEET! Can't wait to find out what this will cost, but first, is there any way to find out if this is the pump for sure? I wonder if a pressure test would work since it doesn't seem to do it all the time. What's a pump cost$$$

[steveknapp]

Been awhile since I had the RT...

 

Does the fuel pump cycle with the kill switch, but the brakes when you turn the key? Would be pretty easy to un-sequence the two this way. Figure out which one.

[Ken H.]

SWEET! Can't wait to find out what this will cost, but first, is there any way to find out if this is the pump for sure? I wonder if a pressure test would work since it doesn't seem to do it all the time. What's a pump cost$$$

Given that the pump is working but just making noise, I don't think a pressure test will tell you much.

 

Chicago BMW list the pump for $183.20, but there are probably sources such as bemmerboneyard that could source a used one cheaper.

[T__]

Willie, before condemning the fuel pump make darn sure the pump itself is the issue.. Place your ear to the fuel tank & then turn the ign switch on.. That will tell you if your pump is in fact the problem area..

 

If just a noisy pump there could be many reasons.. Probably the most common reason for a noisy fuel pump is the pump grounding out to the side of the fuel tank or contacting something inside the tank,, followed by a loose pump in it’s mountings.. Other possible causes could be a pressure regulator problem causing the pump to operate at a very high fuel pressure.. Or even the return line plugged that could drive pump pressure sky high (that will usually cause runability problems also) .. Even something simple like the return line disconnect not being properly pushed together can cause high main line pressure..

 

You might even check the fuel tank venting & vapor canister (open the fuel filler & listen for an inrush of air (whoosh).. If the tank venting is nonfunctional it could cause the tank sides to pull in cold (after sitting a while) or the sender assembly to move..

 

I have seen a lot of noisy or defective fuel pumps (all car/truck related but the same basic pump type) & as a rule when a pump actually fails enough to make noise it makes it all the time not just once in a while..

 

Those internal fuel pumps are pretty hardy with not much to go wrong except loose bushings or loose impeller BUT they can be damaged if the vehicle is run for a long time with very low fuel level (hence the low fuel light usually comes on with plenty left) or if the vehicle is run out of fuel (or as it runs out of fuel).. The fuel pump is fuel cooled so low or no fuel can allow overheating..

 

Twisty

[Willie]

Thanks for th einput guys. The last 2 days, I have not heard it. I am however going to start the bike with the kill switch off for awhile. Kill switch off, turn key, you just get the brake servo noise. Then when all is quiet, hit the kill switch and listen to the pump cycle. Not that I want to hear it again, but it woul dbe nice to know what's going on.

[Willie]

OK, the noise hasn't been too bad lately, but a few times I have heard it. It is definately something with the fuel pump and not the brakes. I have been turning them on separately. But now, I am having this problem again... Previous Thread I turn everything on, hit the starter, fires right up, then a second later, the rpms begin to drop to about 600 and the idle is very rough. Takes a bit of time and revving the engine slightly to clear it up. If I pull out into traffic right away, like I did today because I didn't know the bike was doing this crap again , I hold everyone up until I can get the engine running right and pray I don't get hit in the meantime. I know this isn't a water in the fuel issue as this is the first tank of fresh gas after a complete drain and filter change. I HAVE to think all this crap is tied together. I'm getting very tired of dealing with this at this point. Any idea what a trip to the (dare I say it?)... dealer would cost to troubleshoot this thing? Any ideas. Anyone closeby that can help me out. Thanks

[ESokoloff]

Any chance of it being a defective pressure regulator

 

Just throwing out ideas.

[Willie]

How do I test for this stuff? I taking her out this AM and going to test ride a Buell Uly. Problem might be solved soon Anyway, thanks for all the help. I really want to get this worked out.

[Willie]

Stopped by the BMW shop the other day and scheduled them to look at it. The one guy said it could possibly be a bad or dirty fuel injector, but they couldn't tell for sure until they tore into it. I did reproduce the problem for them, so hopefully that helps some. I really hope that whatever is wrong with is the reason for the bike not running as I would like it to. Wish me luck.