Author Topic: K100 RS 4v no start (Read 7291 times)

Filmcamera · « **on:** January 17, 2020, 04:27:52 PM »

I have been having intermittent ignition issues for a while. Every now and then at certain revs the bike would start to mis, it felt like a rev limiter cutting in. Anyway after an especially bad bout this morning I decided to try swapping out the entire ignition portion of the loom for another I had (the one that came with the bike initially but was chopped to hell and back).

I swapped everything out and tried the bike - no start. I checked all the connections and tried again - no start. The fuel pump primes all the idiot lights come on and the bike spins great, just no start at all, not even a hiccup. So I swapped back to the ignition/fuel injection loom I had just taken off.

No start - exactly the same symptoms.

The only thing I can think off is that when I disconnected the hall effect sensor plug the plug from the sensor disintegrated in my hands leaving five pins in the air. I did not think much off it and just matched wire color to wire color on the other plug. Is it possible they do not plug like that? Can anyone post a pic of the bike side cables?

The wires are red, orange, black, brown and I think greenish but it is hard to see. If anyone could tell me how they connect into the other side I would appreciate it, red to red, orange to orange etc does not seem to work.

I just checked and there IS fuel at the rail but when I press the starter nothing come out of any of the injectors.

daveson · « **Reply #1 on:** January 17, 2020, 05:23:25 PM »

If injectors aren't opening, seems like they're not getting earth (or power)

The colours should match for the hall sensors.

Filmcamera · « **Reply #2 on:** January 17, 2020, 06:11:18 PM »

You are right it does seem to be that but I cannot find out why nor can I find a test for the 4v brick

Laitch · « **Reply #3 on:** January 17, 2020, 07:01:25 PM »

Quote from: Filmcamera on January 17, 2020, 04:27:52 PM

The wires are red, orange, black, brown and I think greenish but it is hard to see. If anyone could tell me how they connect into the other side I would appreciate it, red to red, orange to orange etc does not seem to work.

Filmcamera · « **Reply #4 on:** January 17, 2020, 07:07:05 PM »

Yes I found that and that is what I used to go red to red etc. I also ran a diagnostic on the Motronic and it is giving me two codes saying hall sensor 1 and 2 are not working - I did have the hall sensor unplugged once when I turned the ignition on so I have disconnected the mottonic overnight to see if that clears the codes. If it does not there is a clearly a problem there - though I am not sure that would make the injectors not pulse.

I am trying to find a test to see if power is getting to the injectors when I turn on the ignition or press the start button.

Right now that battery is flat so I am charging it while waiting for the motronic to reset the codes before trying again in the morning.

Sign I have gone from a minor annoyance to a dead brick.

volador · « **Reply #5 on:** January 17, 2020, 08:40:44 PM »

Heat Sink Paste refreshed on the Ignition Amplifier module?

Scott_ · « **Reply #6 on:** January 17, 2020, 09:01:17 PM »

Well, the + power(green/white) for the injectors is controlled by the fuel pump relay and fused by fuse #6.
The - grounding(yellow/grey) lead for the injectors is grounded thru the motronic module when it sees a signal from the hall sensors, or the starter button depressed.

As far as the Hall wiring harness:

Red is + power(pigtail terminal #4)
Black is the - ground (pigtail terminal #3)
Brown is a signal lead (pigtail terminal #2)
Orange is a signal lead (pigtail terminal #5)
Pigtail terminal #1 is a shield lead that is grounded at the same splice as the black lead.

Check fuse F5, un-switched battery power to motronic terminal 18, and relay switched power to motronic terminal #9.

Scott_ · « **Reply #7 on:** January 17, 2020, 09:06:20 PM »

Quote from: volador on January 17, 2020, 08:40:44 PM

Heat Sink Paste refreshed on the Ignition Amplifier module?

That could help the stumbling issues when running, but wouldn't have any affect on 'no fuel' from the injectors when trying to start.

Filmcamera · « **Reply #8 on:** January 18, 2020, 09:50:05 AM »

OK quick update.

All fuses checked and ok

I am getting power at terminals 18 and 5

I am also getting power at the red terminal of the hall sensors at the plug connection

I also get power to the fuel injectors but do not see a ground when I press the starter button.

Where I do not see power is terminal #29 on the motronic connector which is supposed to be hall effect supply and give me 9 volts and I am seeing 0.35 volts but I do have continuity if I check the resistance.

I left the brain unplugged all night but still get errors 1122 and 1133 (Hall effect - no signal No 1 motronic plug connections 8 and 26 (signal)even though I do have continuity from the orange cable at the plug connection to pin #8 and from the brown cable to pin #26.

What I am not sure about is if all that means I have fried the hall sensors or the motronic or something else all together.

I did swap both the motronic relay and the fuel pump relays but no difference.

Filmcamera · « **Reply #9 on:** January 18, 2020, 11:44:37 AM »

Quote

Heat Sink Paste refreshed on the Ignition Amplifier module?

Yes I did it about a year ago

champ7fc · « **Reply #10 on:** January 18, 2020, 12:31:45 PM »

I think I had a similar problem when restoring my K100RS. Since you had the bike running before you replaced the harness I believe the fault is in the harness or a connector on the harness. I had connected two five pin connectors under the tank I checked the wiring colors with the schematic , there are actually , on my bike, three sets of five pin connectors, one was tucked under the harness. The bike would not start. I went through the harness again under the tank, found the other connector with similar wire colors, plugged them together and the bike started and ran normally. If you had the bike running before the change and it did fail to run after, I would suspect the change and not another item on the bike. Recheck your wiring harness connectors, just some input from an old motorcycle tech. Hope it works . Craig

Filmcamera · « **Reply #11 on:** January 18, 2020, 03:53:05 PM »

I have triple checked evry connetor and they all ssem fine. I have now lost power to the injectors as well... I am stumped. Not sure what to do next, any ideas anyone?

Laitch · « **Reply #12 on:** January 18, 2020, 03:56:15 PM »

Quote from: Filmcamera on January 17, 2020, 04:27:52 PM

I have been having intermittent ignition issues for a while.

Have you done anything about this hot mess? It isn't helping matters.

Filmcamera · « **Reply #13 on:** January 18, 2020, 07:08:06 PM »

That is the hot mess I removed yesterday that started this whole mess. Putting it back on has not fixed the problem. I checked for power at every connection that should have one and they all have it. I also removed the top cover on the motronic connection so I could test for power etc with the unit connected. That way I do see 12v from the hall effect sensor into connection 29.

This afternoon I took the entire ignition portion of the loom apart and tested every single wire for continuity. I found two broken wires, one in a fuel injector and one in the air temp sensor plug. Both of those were fixed and the loom re-wrapped and connected. Still the same issue still error 1122 and 1133 from the motronic and still no power to the injectors (again).

I suspect I might be burning relays so I am going to test a few tomorrow.

Apart from that I think maybe I broke the hall effect sensor- I took it off the bike for a visual inspection but there is not much to see and I cold not find a place to test wire continuity so I do not know if it is busted or no. Anyone know of a test?

daveson · « **Reply #14 on:** January 19, 2020, 03:33:52 AM »

Bert's guide at the k100 forum/tech page/electrical/troubleshooting the EFI
(spose it's OK as a guide for 4V)

Filmcamera · « **Reply #15 on:** January 19, 2020, 09:08:02 AM »

I tested the hall effect sensor using Bert's guide (thanks for suggesting it, I had it already but had not seen the hall effect sensor test) and it seems to be bad.

In the guide Bert mentions that the sensor is only $15 bucks. I did a search and found them but it does not seem that easy to take them off the plate etc to replace the bad sensor. Has anyone done this?

I have found a used complete one for $75 so I think I am going to get that.

Now I have to wait two weeks for it to get here.

Thanks for all the help, I will report back when I have the replacement sensor - fingers crossed the bike will work.

Laitch · « **Reply #16 on:** January 19, 2020, 11:27:21 AM »

Quote from: Filmcamera on January 19, 2020, 09:08:02 AM

In the guide Bert mentions that the sensor is only $15 bucks. I did a search and found them but it does not seem that easy to take them off the plate etc to replace the bad sensor. Has anyone done this?

Many owners have done this. Here is a link to a thread post that condenses the process. The thread itself indicates the amount of interest.

billday · « **Reply #17 on:** January 20, 2020, 07:59:58 AM »

EME has one for 160$ plug and play. I think that's how I did it when I replaced mine.

Filmcamera, major condolences for all your troubles, hope you get it sorted soon.

Filmcamera · « **Reply #18 on:** January 31, 2020, 10:12:42 AM »

I finally received the new hall effect sensor last night. This morning I installed it and the bike started right up!

Thanks for everyone's help.

Filmcamera · « **Reply #19 on:** January 31, 2020, 02:08:31 PM »

Well I went for a test ride and the bike is running great!

But...

I now have two new issues

1. When the engine is running turning the key to off the position does not turn off the engine. With the key in the on position hitting the kill switch does not turn off the engine. However with the key in the off position the kill switch does cut the engine. The sidestand does as well.

2. The ABS light is on. I tried the reset and nothing. When I try reading the error code using a 12v bulb all I get is the light solidly on, no flashes of any kind.

Scott_ · « **Reply #20 on:** January 31, 2020, 06:10:03 PM »

Well, to state the obvious, it sounds like you still have some wiring issues to sort out with your ignition switch harness now.

billday · « **Reply #21 on:** January 31, 2020, 06:13:23 PM »

Is your start button / kill switch at all wonky? I've read of cases where that led to all kinds of occult-seeming problems.

alabrew · « **Reply #22 on:** January 31, 2020, 06:57:39 PM »

I didn't see if you had ever cleaned the ignition switch?

BTW, I broke my ignition switch wiring and I have just hot wired a simple toggle switch to turn the bike on and off, everything works as it should.

Filmcamera · « **Reply #23 on:** January 31, 2020, 07:33:32 PM »

I did clean the ignition switch a couple of years ago. The kill switch has never played up before now. It is a weird combination of things, I suspect wiring closer to the relays. When I had the tank off if I kinda fiddled with a few wires it would work again for a bit. Time to start tracing another intermittent electrical issue...

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Author Topic: K100 RS 4v no start (Read 7291 times)