Hello, I'm a Newbie and like most other members, I've come here because of a problem. I recently purchased a K100 Rt (Ebay)that had a bad gastank, but was supposed to run fine. Well, I've repaired the tank hole (about 3/8") and had it painted ($100). Well, what do ya know, the engine cranks fine but the fuel pump dosen't run, but there is no power at the plug that goes to the tank. I haven't had any luck finding it. There are actually two open plugs under the tank that have power to them, but nothing plugs into them. I see this issue has come up before on this forum. Some of the nanes of parts are not familiar to me. I don't know what they look like and don't know where to find them. This is the first time I've even touched a BMW so this will be a slow learning curve. Does this sound familiar to anybody?
2 soon (old)


Number of posts: 5
Location:: BG Ohio
bike: nuthin' everything is broken Working on '87 K100RT,.....not working out very well. Stumped.
Registration date: 2010-10-18

I had the same prob, it was the multiplug under the tank that plugs into the pump. It was loose and had to be reset in its socket a couple of times to make good contact and work again. Have you checked that? It's the round one with 4 wires, left side of the tank.

I have a harness of four wires coming from the gas tank and into a plug on the right side. The problem is there is no power on the engine side of the plug. I'll admit the plug isn't the tightest fit I've ever seen. Thanks for responding, glad to know somebody is reading my posts.

2 soon (old) wrote:Thanks for responding, glad to know somebody is reading my posts.

2 soon, We are all reading your post.
What is nice on this forum is that people will give you an honest opinion. What counts here is not the quantity of posts but their quality!
If nobody has an answer, nobody will reply.
I have read your post and I am still thinking about giving you some direction.
You have to understand that a handful of members are spending a lot of time to help others and we also have to take care of our personal life which takes time too.
Few of us have spent a tremendous amount of time to create the EFI troublshooting page
No where in your post I can see that you followed this troubleshooting page to help you diagnosing your problem.
You never told us if your FI relay is working or if the fuses are OK. Have you tested your water temperature sensor? if its bad, the fuel injection will be cut off. I could give you 10 different reasons why the pump is not working, but do the groundwork first.
Another page being helpful for you is the Electrical diagrams
Are you able to follow it?
Just imagine the time that I invested on this forum to help perfect strangers but fellow riders.... All the 'techies' on this forum are trying to help mostly to keep the spirit of the motorcycle brotherhood alive.
Man, we are not mechanics charging outrageous fees, but a bunch of passionates trying to keep all these old ladies on the road.
Please follow the troubleshooting chart and tell us where you have a problem.
We will gladly scratch our head to find an answer. It is just too difficult to cyber-troubleshoot when we don't have any information on what has been done or tested or what is your knowledge level.
I don't want to give you a bad impression of this forum, but as somebody else had said, "help us to help you!"

Cheers

yes soon this challenge will be behind you and you'll wonder what all the fuss was about - and there will be another one... the EFI troubleshooting chart is awesome, just take your time and follow it through. There are no shortcuts in troubleshooting!

Hi 2 soon,
Take the troubleshooting one step at a time follow the diagrams and I am sure you will fix the problem. Tell us what you are measuring on the test process as Crazy Frog says.
Regards,
K-BIKE

OMGosh, I just saw the EFI page tonight. For a guy who dosen't get along well with electronics, I feel like my brain has been in a blender. I previously was trying to use my Clymers manual and agree with others here about how little it does to answer questions. I thought the Wiring Diagrams here were fantastic, and I was up until 3-4 a,m. last week, copying several of them. To me they are always like a tray full of spaghetti, but eventually they do help.
As I've said before, BMW is all new to me. Lots of parts are new to me. Only my Vmax is water-cooled, and none of my bikes have ever been fuel injected. The EFI page has answered a lot of my questions tonight. Before this I did a lot of poking around with my test light, but only found where the electricity was NOT at. I cleaned my fuse panel because it is exposed and even the fuses were weather beaten. I sprayed contact cleaner in the panel and replaced all the fuses with new ones. What I have found is that #6 fuse has no electricity. Not sure if the fit is just so sloppy it won't make good contact, or if the problem lies elsewhere. I'll be checking it out more. Sure don't like the fit on the fuses though.
I've been working on the Vmax also. Got it running again yesterday, but I think a missed shift last Spring, might be going to cost me a valve job. Came home with new batteries for both bikes today. Thanks for your patience.

2soon (old)

could it be pump your is faulty . . mine was turning but not building up the pressure in the lines . .