So I've had the week from hell. Bike died at Goulburn, on the way back from a round trip from Home (Newcastle) to Canberra. I thought it was water in the fuel tank, as it's had this issue before.. - Roll off throttle, or start going downhill, and the bike dies. Wait till the engine has completely stopped, and it'll restart no problems. Usually it's water in the fuel, and because of the way the fuel filter sits, if it's got enough water in there, it covers the 'face' of the filter and blocks fuel flow. I've had that happen to the car a few times, except that it happens after turning a left corner, because the fuel filter is facing across the car.

I totally drained the tank, emptied the filter, I did have a bit of water in it, but not enough to cause a problem.. Fuel pump seemed a bit weak though. That'd explain the bad idle i've had for the last couple of years, d'oh. After a 4 hour wait for a tow truck, and the mrs driving down to pick me and the trailer I'd bought in canberra up, and then a second trip down immediately after to get the bike home, I proceeded to spend the rest of the nights after work this week making sure the tank is clean, replacing the fuel pump, new filter, new hoses, etc etc.

Took her for a ride, and WOW. Starts on the FIRST press of the starter, idles perfectly, revs smoothly from 1000rpm to 9000rpm, it's a totally different bike! Hasn't ridden like that in 3-4 years!

BUT. 9 times out of 10 when I close the throttle (NOTE: *once* the bike is up to running temp.. when it was cold, it was fine! Going to go unplug the temp sender in a minute and see if it 'comes good' to narrow it down..) the bike dies. I have to pull in the clutch, wait a few seconds, then hit the starter - and I have a 1 in 3 chance of starting it.. It may just fire and die immediately two of those times..

I don't suppose that sounds like a 'known' problem?

Thanks,

Damien

Could be a leaking FPR that wet fouling the spark plug at cyl.4,
check the spark plugs when the problem arises....
and check the inside of the vacum hose leading to the FPR.

Does it cut out cleanly or splutter and miss then die?

Thanks Inge,

had a quick look, and the plugs are all nice - bit rich, but with the amount of starting i was doing last weekend, i'm not surprised.. Vacuum hose to the FPR is nice and clean.

G'day Rick,

It just dies cleanly. As in it's fine if I'm accelerating. It's only when i roll off the throttle - the bike starts slowing down as you'd expect. But when i roll back on, I realise that the bike isn't firing, and she's still slowing down.

Out of curiosity, i disconnected my TPS and went for another ride - exactly the same problem! I'm wondering what else would let the engine know I'm rolling off the throttle..? MAF? Or maybe a faulty ECU? playing with it tonight, it takes about 30 seconds before it's able to be started again.. if I drop the clutch, or press the starter before the 20-30 second mark, it simply won't fire.. Or it'll fire while on the starter, but as soon as it fires and it drops out the starter, she dies again..

I should add, it doesn't have to be when I roll off either.. I sat it in the driveway idling, and it was idling perfectly, then just randomly stopped dead. Wouldn't restart straight away.. 20-30 seconds later, it started fine, and idled for a minute or two again..

From last weekend, i should also add that if I *stay* accelerating, it'll still die within a minute or two of starting.. But rolling off is almost a certainty that it'll die.. I can be doing 8000rpm, or 3000rpm, it just dies..

intersting problem

to check the temperatue sensor ( well partially ) pull the under seat connecor off the computer ....count to pin 10 and measure the resistance to earth ...it should be over 2000 ohms cold (closer to 3000 is still good )

whilst there clean up all the connectors ....plug and socket there ... as this is where the injector control lines feed from and that connection is quite important .

a little while ago my bike sputtered like yours ... then died, almost could get a start ...the connector had come loose ...

there is a efi trouble shooting chart in the "portal page " which could help greatly .

dont forget to test and clean up all the fuses ... and check the starter brushes ...they ground out the load shead relay .

does the lights go off and then back on after a start event ?

just checking all the normal things

Have you checked if the fuel pump will run immediately after it cuts out, that is in the period it won't fire. All you need to do is tap the starter button and the pump should run for 1.5 seconds. If it does fire check inside the tank to see if there is a good solid stream of fuel comming back by the return line, it should not be a dribble but a good flow.
Check your fuel pump pressure, I usually do it by removing the fuel line from the filter and try to hold the line with your thumb over the end and press the starter button, it should be very difficult to hold back the flow (should be 65 psi). Do this inside the tank as fuel will probably go everywhere if you dont. If you got a poor flow check it again against what you get with the filter is disconnected.

Thanks, i'm going to pull the ECU out and clean the connector tomorrow - it's never been off (I've heard lots of stories about never getting them sealed again after removing them..) in its life so far, so could be dirt in there finally.. I notice that pin 8 on the ignition control unit to pin one on the ECU is the engine-running signal.. I'm curious if that line is dirty - might lift the tank off tomorrow and test it from unit to unit to be sure.. woudln't surprise me if that's become dicky..

Lights operate as normal, off while starting, come back on after started..

Question, anyone know (maybe someone could try it out? ) - if the bike is running, and you randomly tap the starter button.. Does it confuse the ECU and kill the bike? My starter button broke the day before all the trouble started (could be coincidence...), and while it *just* stays out, so you have to tap it to start the bike still, it does occasionally depress itself as you go over bumps (noticed that with the bike dead, rolling to a stop many times last saturday night.. go over a bump and it'd momentarily try to start..

Would be neat if someone could give that a try I might disassemble the switchblock tomorrow and put a different pushbutton in to see if that's the problem.. Have a new one coming from motorworks UK - just waiting on it..

Yup, fuel pump pressure is fine - I replaced the pump this evening! Made a HUGE difference to the bike's running - the lousy idle and low-acceleration problems I've had for a few years have all gone away! It's also WAY more pressure and stream volume than the old pump!

But this new problem is still there..

BTW, I'd be really careful trying to hold back anything over 14psi with your thumb..? dad always cautioned me to be careful with the compressor, lest I break the skin and get air bubbles in my blood stream.. Although maybe he was FOS

Rick G wrote:Have you checked if the fuel pump will run immediately after it cuts out, that is in the period it won't fire. All you need to do is tap the starter button and the pump should run for 1.5 seconds. If it does fire check inside the tank to see if there is a good solid stream of fuel comming back by the return line, it should not be a dribble but a good flow.
Check your fuel pump pressure, I usually do it by removing the fuel line from the filter and try to hold the line with your thumb over the end and press the starter button, it should be very difficult to hold back the flow (should be 65 psi). Do this inside the tank as fuel will probably go everywhere if you dont. If you got a poor flow check it again against what you get with the filter is disconnected.

If you touch the starter button and the engine is over 711 rpm the starter will not engage but an enrich signal will be sent to ECU but the ECU should not cut the engine.
If you try to bump start the first time the hall sensors tell the ECU to fire the pump will run for 1.5 sec or if the bike continues to run the pump will continue also

The starter button could be the reason to your running rich problem...if it shorts while driving, you get a richer mix, but the starter won't be enabled as long the engine turns above 711 rpms.

Ahh, ok thanks Rick. Yep when I bump start it, the fuel pump fires up for a second or so.

One more thing to cross off the list!

Oooh, I think I might have found it! After much playing, i confirmed that it had nothing to do with throttle position - seemed to really be more of a time thing - so maybe heat related.. Started looking at the wiring diagrams, and came to the hall effect sensors. Removed them frmo the bike, wired up a test harness, and they looked good.. then popped the heat gun on them.. sure enough, about 80C and one sensor stops doing a straight on->off transition, but starts giving a variable output - small amount of metal in it, small amount of light.. large amount of metal, no light, no metal, full light.

Off to repco to see what they have in stock that might be compatible!

Don't go buying a genuine will you. We don't do medical recoveries from fainting at a dealers counter.
Try here http://www.bbautomacao.com/home_hall_effect_sensor_cyhme56.html

Haha, never!

I found a 'performance' workshop in sydney who purports to stock the HKZ121's which look to be compatible.. Will give em a call on Monday if I don't find anything suitable at repco

rs components list a 4av13a

which looks similar

http://australia.rs-online.com/web/p/hall-effect-sensors/1785689/

57 bucks though

Jaycar...20 dollars. HKZ-101 Hall Effect Device.

Have a look here. It includes a pdf with dimensions.

blakey wrote:Jaycar...20 dollars. HKZ-101 Hall Effect Device.

Have a look here. It includes a pdf with dimensions.

hahahahah! I drove past jaycar this morning, saying to the mrs, 'nah, they only have the little ones I use in my robots.. They wouldn't have automotive versions!'.

When I was a student at agri college, I was told a story during tractor health & safety. A farmer was driving his tractor up the road and the link box at the back kept dragging the ground. He would raise it only for it to drop back down. He noticed a pin prick hole in the hydraulic hose so he raised the link box, put his hand around the hose covering the hole to get home. He ended up losing his arm due to hydraulic fluid being forced into the skin under pressure from the pump.

G

Whilst in Jaycar hit them up for some DeoxIT, accept no substitutes which they say are "just as good" they are not! Ideally you want the kit with two glass bottles with little brushes inside (I suspect they buy them from the same suppliers who do nail varnish). When you have the genuine give the CPU plug and socket a good going over to clean them up and plug them together a few times and make sure when it is finally in that you hear the click of it latching home so that pulling it will not let it come loose our esteemed CF had that problem.

The troubleshooting chart is worth following as it logically steps one through the process. The main issues seem to be bad electrical connections due to oxidation and corrosion, a few members with faulty Hall sensors, we have also had a few members with faulty fuel pressure regulators which are a pain to get to but easy to fix by replacement.

If the start button was intermittently connecting whilst the engine is running the starter will not turn but the mixture gets a bit richer not rich enough to kill the engine stone dead.

Glad you have traced the faulty behaviour of the Hall sensor they are fiddly things to replace but there is lots of info about how to do it.
Regards,
K-BIKE

Booyah! It's alive! Took the better part of an hour to replace the hall effect sensors - the old wiring is crimped, not soldered, so was 'fun' getting those 30 year old crimps off, and getting the wires to tin. But all good

It's a COMPLETELY different bike, not sure if it was mainly from the new fuel pump, or if the failing ignition trigger made a difference too, but it has a rock-steady idle (revs still travel up and down a little, but it doesn't have the regular once-per-second misfire that it has had on idle for going on 5 years!). A 2000rpm roll-on in 4th is just magical, and the off-the-line is back to the 4ish seconds it's supposed to be! Bugger me, I'd been missing that!

The only thing that it still has, which has been bugging me for years, is it dying on a long downshift.. That is, if you use the clutch on a downshift, and keep it in a little too long, the ECU doesn't kick the fuel back in at 3000rpm like it should, and the bike dies.. You then have to re-start, or drop the clutch and roll-start it..

Which leads me to ask.. I was riding it yesterday on my test rides, with the TPS completely disconnected.. and noticed NO difference to the behaviour of the bike.. Should it be noticeable if you disconnect the TPS? I'm wondering if mine has died? Guess i get to pull the computer back out and test the signal

If you disconnect the TPS it won't cut the fuel (and not give a richer mix at WOT) above 2000 rpms at closed throttle, that's all.

Inge K. wrote:If you disconnect the TPS it won't cut the fuel (and not give a richer mix at WOT) above 2000 rpms at closed throttle, that's all.

Ok, might be a dodgy microswitch then - I noticed when the bike was dying, that the back-off was a lot harsher with the engine shut down, than it usually is when I'm simply rolling off the throttle.. And I'd always thought on these bikes that closed throttle was basically the same as turning the engine off..

Might go veg on the couch till it cools off a bit, then go test the TPS

Cheers,

DG

sounds like you still have some ignition/ injection woes and a huge air leak

wouldnt mind betting the injectors could do with a good clean up

new plugs make a good positive outcome ...(ngk d7ea)

make sure you have the ferrules... either excange the ones you already have or get some ....they normally arent supplied and get forgotten about leaving a nice gap between plug lead and plug ...

throttle body rubber sound rs to me as well

yes check the tps ...for a short as the throttle closes (micro switch inside there) ... and also for another short as you aproach wof (wide open throttle ) different cable returns))

I'm with Charlie about checking the HT part of the ignition.

I had a bit of the same symptom at my K11 some years ago.....which did happen now and then when rolling with throttle off, and only under this circumstance.
When getting back on the throttle it did run only on three cylinders....had to give a good handfull and high rpms to get the last one back.

It turned out to be a loose spark plug cap.........

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About the TPS: if it's shorted, the problem would be that the engine wont run above 2000 rpms.

My two penny worth.

I put a strap round the cpu to ensure the plug is fully home at all times.

I always disconnect the tps and find it shuts down better and handles better in bends of which we have many here in the UK

Halo's elec connection fell out a number of times until RT handed him a little cable tie...problem fixed...easy squeasy

You mean that all he has is a zip tie holding the halo up.

Damien,good to see you're moving forward in the problem solving .
You will have it running smooth in no time at all.
cheers Ed.

Inge K. wrote:I'm with Charlie about checking the HT part of the ignition.

I had a bit of the same symptom at my K11 some years ago.....which did happen now and then when rolling with throttle off, and only under this circumstance.

That's a good point.. Back many years ago, after I mistakenly took barry way to get from melbourne to thredbo for the snowy ride (it looked good on paper.. Was the worst 4hr of my riding life in reality!).. After that ride, I was down about 30% on power, and the bike would never start easily when cold.. Was only 4000km when I got back from that couple of weeks away, that I discovered that the ferrule on #1 plug had come off, and I was running on 3 cylinders.. It always seemed ok afterwards, but I'd wondered if I'd damaged a coil.. Will check it out!

charlie99 wrote:wouldnt mind betting the injectors could do with a good clean up

Can you get the injectors on our bikes cleaned? I was under the impression that the only failure they would get was when the o-ring inside died, and then they're R/S.. And at the price of new injectors, I was always loath to touch them..

If I can get them cleaned, I'd be thrilled, they have to have built up some crud at 120,000km old!

They are the same as any bosch injector of the period and there are many places who clean them. Try putting some injector cleaner in the fuel first it often perks them up no end.

Well, I don't know if it was the injector cleaner, or the 3 degrees of timing adjustment I made the other night (at idle, it was about 2 degrees from the centre of the V, not the 6 it should be), but it's a completely different bike! Sooooo smooth! And back to the twitchy throttle it had when I bought it all those years ago!

Now, before karuah in 3 weeks, I need to do the timing chain, and the TB boots Occurred to me while doing the timing, that the nasty rattling noise I hear whenever I start it on a cold morning, is the timing chain! Bloody easy thing to do on these bike, so will do it asap

Should I order a new tensioner to go with, or are they generally serviceable? (Bike is at 121,000km, I've had it since about 70kkm, and it hasn't been done in that time..)

While I have the engine covers off, I think I'll bicarb blast them, prime, and paint them black - think it'll be easier to keep clean that this darned bare aluminium that keeps corroding in the humidity of the central coast!

You're best to get the kit for a timing chain, it's more likely the guides are worn out and not the chain but I have done all at the same time. Just gotta be careful getting the seal on behind the hall sensors.

Rick G wrote:You're best to get the kit for a timing chain, it's more likely the guides are worn out and not the chain but I have done all at the same time. Just gotta be careful getting the seal on behind the hall sensors.

yeah, I was gonna get the kit, just to be sure - but it doesn't have the tensioner in it, so I wasn't sure if i should grab that too? (Or at least the kit from motobins doesn't..)

Yeah you will need that as well.
So you plan on Karuah River, should see you there be good to meet.

Rick G wrote:Yeah you will need that as well.
So you plan on Karuah River, should see you there be good to meet.

Yup, been there every year for the last 5 or something. This year I'll be camping overnight

This is the K1100 and will be with a blue transalp

Oh cool, this is my old beast:



She'll likely be parked under a 3mx3m portable gazebo

Well bugger me, i was reading a thread earlier, where the OP was mentioning a coil or plug lead failure, making his bike sound like it might be having a bottom end failure, when cold.. I've been concerned about this for a couple of years - ever since the winter immediately following a certain snowy ride I did, where the ferrule on #1 cylinder unscrewed, leaving me running on 3 cylinders for ~6,000km.. The problem (awesome) think with the K100 engines, is it's not overly noticeable if you're down a cylinder, other than dropping about 25% of power..

So I just popped out the garage and tested them. The front coil (1&4) is 2.6R and 10.2KR. So not too bad. Rear coil? 2.4R, and No reading. So something hinky there! I'm guessing it has a hairline crack in there somewhere, as it's fine once it warms up. I'm guessing running on only two cylinders (?!?!?!?!?) would explain it running like crap when it's cold though? Is that primary coil earthed in the centre, or does it really discharge between the two spark plugs?

Effectivly it has one plug on each end of the coil and uses the engine as the conductor to complete the circuit.

hmm

can only pass on what i found rendrag

measure the leads between the plug tops and the coil ......if they are silicon leads they could be resistive (good thing ) they should be within a few thousand ohms of each other ie plug 1 lead on mine measures 3.2 k . plug lead 4 measures 2.3 k or there abouts ...the reason for mentioning that ...is that those 2 are tied together

same thing applies for plugs 2 and 3 .....they should be withing a few kil ohms of each other ....GIVEN that they are the same brand and type

measure between the high voltage towers of the coils ....somewhere about 10k - 12 k should be measured ..( you may need to get a paper clip to extend the connection to get to the terminals with your multi meter .

again the same should be read from coil 2 ...(2-3)

we have seen many reading that vary ....in some cases the coils are open circuit completly ....with a multi meter ...but work when in actuall operation .....there has been lots of post about this

i figure that the coils suffer from some form of high resitance durring their life ......when this happens the actuall voltage comming out of the coils is markedly increased ...ie from a standard 10,000 - 20,000 volts under normal conditions to the high resistance condition where the actuall voltage can increase to well over 30,000 and closser to 40,000 volts or more because the spark condition has not happened ...and there is less load placed on the coil so the voltage increases proportionatly until the event happens .

in turn this can affect the internal winding of the secondary windings (high voltage side) causing possibly a short condition between a couple of different layered coils on the former ( known as "shorted turns") as the spark jumps from one layer to another ... in turn this can create a high current draw which in fact can open circuit the winding internally ....resulting in a lower than normal spark ...and when measured with a multi meter = open circuit = infinity ohms

if you have leads that measure a few killohms each ...there is no need to run "resistive " type plugs so the standard plugs to use would be d7ea plugs for example ...if the leads measure a low ohms measurement run dR7ea plugs

it is important that the load presented to the coil is consistent ...which sadly is not always the case over the years

what you are tyring to acheive is about 5,000 to 10,000 ohms resistance before each spark gap at either end of the coil ,,,( the coils are a wasted spark so rely on the fact that the voltage will in fact go from one earth of one of the plugs to the other earth of the other plug of the "pair ")

because the whole thing is a transformer as such, the process is a transfer of "change in voltage " and not a direct connection as would be on the low voltage side of the coil (from the ecu to the coil ...= dc voltage ) it is the change from no volts to some volts that is transfered and simarly some voltage to no voltage, the change creates the spark at the secondary end ( often called ac durring this process ) the frequency of the "ac" is relative to the motor revs so 50 hertz equals about 3000 revs ( 50hertz (cycles per second ) x 60 seconds = 3000 rpm )

it is important that you have simarly graded leads on each plug as differences could well mean that the efficiency and voltage produced at each plug could affect firing at different mix and load conditions .

does this help ?

Also check that the coil core is properly grounded, at both coils.