Fuel pump/starting trouble

[sebas2357]

I jumped the pump from right side of fuse 4 to left side of fuse 6,I can hear the pump wizzing away.
PUMP WORKS ! good !

NVM, ignore my previous reply. If the pump whizzes on, then you can rule it out as a potential issue. This means that your issue is most likely wiring related based off the previous thread replies. I don't have the most knowledge related to the electronics/wiring of the K bikes, hopefully with the input of someone more knowledgeable you'll be able to get your K back on the road soon.

Seb

[spextattoo]

THX SEB

[daveson]

You want to do the tests suggested by Scott with the start button pressed.

When you press the button the contacts in the fuel relay should close, providing battery power from the red lead, to the green/red wires, one to the pump, the other to the injectors. While cranking you should also be able to hear the injectors clicking on and off.

[spextattoo]

I don't think I can hear anything over the cranking noise...thx

[rbm]

Test results fuse #6
< .... essentially no power ... >

Ok, so it's pointing to the FI relay.

- test for +12V on one of the Green/Red wires on one of the injectors or on Pin 9 of the ECU with (1) ignition on (2) kill switch normal position (3) start button pressed.  If you don't get that, this could be the relay, or the socket.  Pull the FI relay from the socket and while its out, clean the pins.

- On the FI relay socket, Test for +12V on Pin 30 (Red).  It should be present whether or not the ignition is on or off, whether or not the kill switch is on or not, whether or not the start button is pressed.  If its not +12V, you have a battery positive wire connection fault. Look at the sires connected to the battery positive.

- On the FI relay socket, check for +12V on pin 86 (Green/Yellow) when the (1) ignition is on and (2) kill switch is normal.

- Replace the relay in the socket. Insert it and remove it several times to wipe the contacts clean of potential corrosion.  Test for voltage on fuse #6 with (1) FI relay installed (2) ignition on (3) kill switch normal (4) start button pressed.  If you still get 0V, then FI relay is bad.  Replace it.

- The very last possibility if its none of these is that the Hall sensors or the ICU are acting up.

[spextattoo]

After messing with it today,the fuel pump started acting the way it should,I can hear it working a second after I let go of the starter button.
Beats me.... will do the above test tomorrow and let you know .Thx again for sticking with me, much appreciated RBM

[frankenduck]

It's very easy to avoid blowing up the gas tank when you jump power to the fuel pump.  Attach ring terminals and screw them onto the fuel pump terminals BEFORE giving them any power.  You will not generate any sparks that way.

I had a guy come by my house once who was riding his bike around with jumped power to the fuel pump via two wires under the gas cap.

[rbm]

sounds like an intermittent problem which points to bad connectivity, loose connections, corrosion and stuff like that.  Just go through your electrical relay box and use Dexoit to clean and protect connectors.  Reseat the connectors (like relay sockets and fuses, etc.) repeatedly to that the action of inserting and removing and reinserting the connector pins wipe away the corrosion.

[spextattoo]

Gonna finally solder in the new plug tomorrow,had it with the uncertainty THX again Robert

[Laitch]

Gonna finally solder in the new plug tomorrow,had it with the uncertainty.

Please post a photo of the plug and the sender to which it connects, Spex.

[spextattoo]

Its the 4pin  plug that connects to the sender unit at the left front side of the tank.It was also in the beginning of the thread,but somehow not there anymore THX

[spextattoo]

It's very easy to avoid blowing up the gas tank when you jump power to the fuel pump.  Attach ring terminals and screw them onto the fuel pump terminals BEFORE giving them any power.  You will not generate any sparks that way.

I had a guy come by my house once who was riding his bike around with jumped power to the fuel pump via two wires under the gas cap.

 You can jump the fuel pump from outside the tank by bridging right side of fuse 4 to left side of fuse 6,no sparks no explosions,happy neighbors..and you're still alive...you can also empty the tank this way...

[Laitch]

Its the 4pin  plug that connects to the sender unit at the left front side of the tank.It was also in the beginning of the thread,but somehow not there anymore THX

Show the plug assembly at the floor of the tank from which the wires emerge that connect to the plug in your photo above.

[spextattoo]

Location of the 4pin plug at the sender unit at the left side of the tank,tilt your head to the left,don't know what happened here

[frankenduck]

You can jump the fuel pump from outside the tank by bridging right side of fuse 4 to left side of fuse 6,no sparks no explosions,happy neighbors..and you're still alive...you can also empty the tank this way...

That does not work if the connection to the fuel level sender is flaky. The only way to be 100% sure that the fuel pump is getting power is to jump directly to it.

[spextattoo]

Ok, so it's pointing to the FI relay.

- test for +12V on one of the Green/Red wires on one of the injectors or on Pin 9 of the ECU with (1) ignition on (2) kill switch normal position (3) start button pressed.  If you don't get that, this could be the relay, or the socket.  Pull the FI relay from the socket and while its out, clean the pins.

- On the FI relay socket, Test for +12V on Pin 30 (Red).  It should be present whether or not the ignition is on or off, whether or not the kill switch is on or not, whether or not the start button is pressed.  If its not +12V, you have a battery positive wire connection fault. Look at the sires connected to the battery positive.

Hi there RBN,
thanx again for all your help and patience,very much appreciated. Just a conclusive summary :
So I got her running,overheating problem solved,the fan kicks in eventually by the time the bike goes up to temp.
I had put a new temp sensor and thermostat in and removed the vacuum switch on the throttle body as well as plugging the barb on Cyl 1.
I didn't want to cut away insulation on the injector wires and didn't know how to test them otherwise,so I moved down the list of your suggestions.
The first thing I did was to check the electronic ignition and it seemed that the plug was not securely inserted.
The next thing was to replace the 4pin plug at the tank with the one from the alarm system.
Trying to figure out which one of the ocean of relays (attachment 3)was the FI relay you were talking about,I went to the manual and in the pic it shows 2 fuel pump relays ,as they call it. (see attachment 1)
So I measured the socket at pin 30 on relay5 ,ignition on,on my model there was no red wire,but a green/brown and I got 12.70 V.
( don't remember if that was with starter pressed )
Then measured pin 86 at the socket,ignition on and got 12.56 V.
(again,don't remember if I had the starter pressed or not,but I got voltage )
The measured on Fuse6 ,ignition on,starter pressed and received 12.56 V on both sides of the fuse.
I didn't check fuel pump relay2 (see image 1) cause there was no mentioning of the pin layout anywhere in
Bernd Vogel's EFI troubleshooting Manual (attachment2) so on I went,put evrything back together and wouldn't you know it it fired right up.
So my guess would be, that first of the Electronic Ignition plug was loose, and the second thing was the 4 pin plug to the pump/sender unit was faulty (attachment4)
Just wanted to clarify in detail, in the hopes of it helping some other mechanic master mind like me,to get their bike back in motion.
So thank you so much for running me through this in detail and helping me find the problems.Your patience is unmatched !!!

[daveson]

Actually the labels for the drawing are wrong. It should read;
3 - fuel relay
4 - load shed relay
5 - horn relay
6 - temperature relay
7 - bulb monitoring unit
8 - starter relay
11 - flasher unit.

[sebas2357]

This is the relay box diagram for an 85 K

[spextattoo]

This is the relay box diagram for an 85 K

I have a RS not a K ,if that makes a difference.Took the pic straight out the Clymer Manual page336 ,don't know what to say or believe anymore...and the bike runs and works properly,That's what matters THX

[spextattoo]

1985 K100 RS

[rbm]

Well, don't believe Clymers. That diagram got the FI, Horn and Load shed relays wrong as well as labeled the BMU as the second FI relay

[spextattoo]

Actually the labels for the drawing are wrong. It should read;
3 - fuel relay
4 - load shed relay
5 - horn relay
6 - temperature relay
7 - bulb monitoring unit
8 - starter relay
11 - flasher unit.

I only have 7 fuses,not 11

[daveson]

Those numbers in the drawing relate mostly to relays.

The Clymer manual is good, but that is one of the mistakes in it. A simple test, the horn relay which Clymer calls the fuel relay, remove it, then the horn won't work but the pump will.

[spextattoo]

You might be right and I might just try it out,THX

[sebas2357]

I have a RS not a K ,if that makes a difference.Took the pic straight out the Clymer Manual page336 ,don't know what to say or believe anymore...and the bike runs and works properly,That's what matters THX

85 K refers to any K bike made in 1985. The diagram is relevant to your bike. I have the same motorcycle.