Hi K riders,

I finished off the last job, a bit of drive train stuff. So now to the unreliable idle and such.
The K100 has been easy to start, but hard to keep going especially when it's yet to warm up, even then it needs a bit of nurturing to keep it running while stopped at lights and the like.

OK so first stop after referring to CF's ignition trouble shooting doc (thanks for that by the way CF).... Fuel pump pressure, which from memory should be 65psi out of the pump. Oooooooh doggie, mine is delivering over 100, it's topping out the gauge (dodgy chinese one, but I did plug the upright bike pump into it and it seems to be reading accurately enough)

Oh OK sorry just checked (CF doc) again, problem with the pumps internal relief valve? serviceable problem? I'll keep looking.

Jez.

This is where I got my new pump and used a couple of big zip ties to hold it in http://www.ebay.com.au/itm/Fuel-Pump-Ford-Falcon-EA-EB-ED-EF-EL-XF-XG-XH-LTD-NA-NC-/151128415938?pt=AU_Car_Parts_Accessories&hash=item232ff49ec2

You can service but IMO it just aint worth the time considering the price of a new one.  I bought 2 and have a spare around to make sure it never stops working again.

Although the fact that the fuel pumps relieve doesn't work (65 psi) that's a non-issue as your fuel pressure controller (the blob behind the fuel rail) is supposed to keep the pressure in the injector rail on 25 or 30 psi depending on the bike you have (IIRC). So why replace the pump? Or am I missing something?

If you have tested the fuel pressure with an inline gauge, this reflects 2 problems:
The fuel pump relief valve is not adjusted correctly and the external pressure relief valve is stock or not working.
I agree with ReneZ that the external relief valve should drop down your pressure to 36 psi
If I remember correctly, Ajays gave a solution to unlock or unstock an external pressure relief valve:
Unhook the line going to the external valve and blow about 120psi of air pressure in the hose.
I wouldn't play with the pump until the external valve is OK.

CF

ReneZ wrote:Although the fact that the fuel pumps relieve doesn't work (65 psi) that's a non-issue as your fuel pressure controller (the blob behind the fuel rail) is supposed to keep the pressure in the injector rail on 25 or 30 psi depending on the bike you have (IIRC). So why replace the pump? Or am I missing something?

If the pressure relief valve in the pump isnt working then it is likely the volume pumped and so the pressure will overwhelm the FPR.
If you disable the relief valve in a pump you will be astouned at how much volume they will pump.The relief valve and the FPR would both be working to keep the pressure and volume under control.

Ok so today I finally got the replacement aftermarket fuel pump in and it measured 100 psi too! well at least at about 100 psi the pressure relief seemed to activate.
I should have measured the "in line" pressure before as you suggested CF because although the pump O/P is running at 100 in the in line pressure is indeed running at about 35(well the gauge is bouncing between 30 and 40 whilst running.)

I dunno if this is just a pressure wave as the injectors relieve pressure with their release event of if it should read steady. Anyway, the vacuum hose that runs from the rearmost throttle body to the FPR seem a little tired, it makes no difference to the running when it is removed and it is removed (just about falls off) really easily. Nor does it affect the fuel pressure.

Any old hoo, before I completely lost me mojo this arvo, I removed the right side lower fairing with the intention of taking out the necessary stuff to get to the fuel reg and inspect the Vacuum line when I came across this schemmozzle!


I'm about to read up and identify the unconnected bits, but why is the wiring so shot!!!?

I assume after I get it remedied and the vac hose in order, it might run a little better.

I had a bit of a look around for the spring from around the vacuum hose (missing on mine, stops chaffing?) and couldn't find one to buy. HEY ROSSKO! where did you get that natty one I saw on one of your posts? Sorry, I couldn't find the entry.

I'm up against it for time at present, so I hope I'll Git R Done before Chrissy, the rego's out and I wanna get it back in before I gotta go through all that  palava of the three month lapse.
Oh yeah, it's an '84 2V RS for those who where wondering.

Jez

OK, you have a very early K, as the little vacuum switch on the rail (pink/green wire) was only on the early ones. On the top there's a vacuum hose going to the first throttle body, a bit like the vacuum hose on the last TB that goes to the fuel pressure regulator. If those hoses are in place and leaking your bike will draw false air and run rough. Further the wiring from the bit underneath the radiator is the wiring from your cooling water temperature sensor which is REALLY important for the fuel quantity adjustment during running and for the switching of the fan. You have some work to do :-)

That looks very like rodent damage when the little buggers are so hungry they try to eat anything.
The switch that connects to the vacuum port on #1 TB is a redundant piece of junk and can be didposed of by throwing at the offending mice but I doubt it will do any good there either.  BMW disposed of the thing in the 85 models with no ill effect.
The piece to the lower right is as Rene said the temperature sensor for the ECU, Temp light and Fan and needs to be kept connected.
The vacuum stub at #4TB is for the Fuel Pressure Regulator and needs to work and have the wire springy thingy on it to prevent it from creasing.
Place some ratsak in the there before you put it back together.

The wiring to the water temp sensor must be half good, the fan still switches on in heavy traffic, but that hangy looking bit must be the wire to the ECU.( does the early model have the temp sensor with two wire connectors? One for the ECU one for the fan?)
Is a case here of replacing the wires with new lengths/ segments? Is it part of a larger switch harness or is it a part that can be purchased?
:| 
Jez

That temp sensor is actually two sensors in 1 housing oneside feeds back to the ECU at terminal 10 on the plug and the other to the fan to terminal E on the temp sender relay in the relay box they both have the same colour wire, Violet with a green tracer.

Yeah, in the thick of it now, vacuum pump gone, wires cut got the two green/violet wires which I'll check to their respective destinations. As I think I said, the fan seems to be coming on, but I suspect that the other one isn't making it to the ECU, would a short on the ECU line affect the run to the fan switch side of things though?

Anyway hats off and a free beer to you Rick for the mouse call, it sounded feasible enough but I was gobsmacked to find this......

I'll test the cable runs and the water temp sensor and see how I go.

Anyone got any ideas for a generic vacuum tube from the TB to the FPR? do Repco, Supercheap or Autobarn carry this stuff? would hard plastic fuel line from the hobby shop work? Just how strong (resistant to collapse) does it have to be?

Jez

You need the thick wall vacuum line. the plastic will colapse with the heat and Vacuum and go hard very quickly.
Usually Repco or Supercheep have the rubber line, it's also used on windscreen washer line sometimes.
I had a friends Kawasaki Z1000  here sometime ago fixing the rodent damage and it was heaps worse than that. The buggers built a nest under the tank and it seemed they can actually live on plastic insulation, there were droppings everywhere and not a sign of plastic anywhere in them.

So I finally got round to setting up the water temp sensor to test it's operation this evening after work, shoulda nicked a retort stand from school back in 1980!


The results are below.




Whaddaya reckon?
I could only start out at 25 deg, (my thermometer only had markings from about 30) and that was a bit of a guess, and I stuck it in some water in the freezer ice cube tray not yet solid. An unknown temp, but must've been below 5 and it read above 4k each side.
Does anyone have an idea whether that discrepancy at 25deg would put the fuel mix out? Is it a keeper or should I replace it?
Expert opinion needed.

Cheers,

Jez

That would be OK at that temp it would only be a transitional thing and would be running fairly rich anyway.

close enough for all aussie riding I would guess

seems you just need to see similar values at pin 10 and 13 of the under seat ecu [plug

anything under about 15 c soon changes as the temp increases to operating temperature during warm up to well over 70 c

Thanks guys for all the help so far, this forum is agog with K Bike Whisperers.

I'm gonna start another thread for this bike as I'm pretty much chasing a single problem, but posting too many threads.

As it's an engine running problem, I'll keep it here in the Engine and transmission section, but try to get some consistency and continuation as I go through the various areas of possible problems, as I think it needs a wholistic approach.

You guys Rock.

Jez