Hessian wrote:Well the fuel is pressurised, in that it really shoots out of the hoses if you dont have one connected... 

I just havent manometered it, because I don't have a manometer.

Manometer is for checking the comparative pressure (vacuum) at the throttle bodies on a running machine. Pressure gauge for fuel pressure from the pump or at the fuel rail. 

Bill

Thanks for the clarification Bill. Will the injectors fire if there is less than ideal pressure?

So is it still not firing up after you confirmed pulsed Vs at the injector plugs??

"it really shoots out of the hoses if you dont have one connected..." doesn't mean anything.
The fuel pump pumps at around 60 psi at the pump which is regulated down to 36psi at the fuel rail by the FPR. If you have a hose disconnected when the pump goes on, fuel will of course gush out quite fast with 60psi behind it. If the FPR is stuck open then fuel just returns to the tank and there's no presssure built up in the system.
What you need to look for is pressure at the fuel rail after the fuel pump has stopped. This would indicate that the FPR is maintaining fuel pressure at the rail (36psi hopefully) instead of letting fuel return to the tank.

"Will the injectors fire if there is less than ideal pressure?"
The injectors will open but with fuel returning freely to the tank and therefore no pressure behind them nothing will come out.

Assuming the injectors are fully functional, they will 'fire' as long as the electrics are in order. Injectors are essentially a spray nozzle with an electrically operated tap. When electricity is supplied, the tap opens to allow the fuel (under pressure from the pump and regulator) to flow through the spray nozzle. If the fuel pressure is low or absent, opening the tap will have low or no effect. If the spray nozzle is restricted or blocked, less or no fuel will flow. 
Injectors being fully functional electrically means that when electricity is applied, the valve opens. If the electromagnet coil is burnt out, or if the moving part of the valve is stuck, electricity applied still means no valve opening.
Of course, even if the injectors are perfect, not getting the right electricity output from the FI computer also means no fuel is injected. 

The list of things that can go wrong is extensive, but the same applies to carburettors. I still prefer fuel injection, even in the early types like the K bikes. 

Bill

I havent had a chance to see if the injectors squirt now Im getting pulses from the loom. I'll let you know the results.

I also don't mind fuel injection over carbs. At least this is much easier than cleaning all the carb bits, putting it all back together and then balancing everything

While not related to this problem, it's also important to understand that all injectors open and close at the same time, twice per engine revolution (4 times per cycle). It is only the duration of the injectors opening which is controlled by the FICU.

indian036 wrote:.....
Of course, even if the injectors are perfect, not getting the right electricity output from the FI computer also means no fuel is injected.

Forgive me Bill, I'm just being really pedantic mate, but there is no voltage output from the FICU to the injectors. It's very simply a switching device which earths the injector coils thereby turning them on. They have continuous power applied to them from the the battery thru the FI Relay.

Kaptain Holister wrote:While not related to this problem, it's also important to understand that all injectors open and close at the same time, twice per engine revolution (4 times per cycle). It is only the duration of the injectors opening which is controlled by the FICU.

I thought that the injectors for 1 and 4 and then 2 and 3 as in 2 twins the spark is that way isn't the injection that way

Hey K75cster
the injectors are connected in parallel and are all switched to earth on pin 12 at the same time

K75cster wrote:

Kaptain Holister wrote:While not related to this problem, it's also important to understand that all injectors open and close at the same time, twice per engine revolution (4 times per cycle). It is only the duration of the injectors opening which is controlled by the FICU.

I thought that the injectors for 1 and 4 and then 2 and 3 as in 2 twins the spark is that way isn't the injection that way

Early injection systems operated as the Kaptain said. The most modern have sequential injection which means that injectors fire individually as the air is sucked into each cylinder. 

When the changeover happened is highly variable on brand and model of vehicle (car and bike), and I have no idea when BMW made this change, but certainly the Ks are well before.

Bill

IT LIVES!

Well it got the jump on resurrection Sunday by a couple of days, but the K100 spluttered to life today.

Noteworthy bits

The bike runs rough, but I have the old injectors on there, not the refurbed ones. 
Doesn't like throttle
When ignition set to on, the headlight doesn't come on. When switched to park/accessories, the headlight does come on.

ITS DEAD

Haha, well I went to put the new injectors on today with dreams of test rides up and down the street, alas, it was not to be.

Popped in the refurbed injectors, hit the starter and while it cranks, it doesn't fire. At all. Took out my tester, getting all the nice flashy pulses from the plugs and thats all.

So the final thing will be to get the roughly working injectors refurbed locally and send the others back if it turns out everything works once the refurbs go back in.

Have you checked if the injectors functions?
On a other forum one did refurb the injectors last year, mounted them this
spring.......all four was stuck.

Hi Inge K, I have not checked to see if the injectors work before putting them on the bike. A forum member let me borrow them as they are freshly refurbished, so we assume they would work...

Use a screwdriver as a stethoscope by holding it against an injector and against your ear. Crank the bike. There should be a distinctive "click" heard through the screwdriver. If not, the injector being tested is quite possibly frozen.

If you clip test leads to the spare injectors, and test by putting them across the battery terminals, the injector should click and you can feel the click as you hold it in your hand. Those that respond to this test are good candidates to replace the refurbished ones currently in the engine but presumed failed.

This strategy will yield one or more "working" injectors. At least you should get some life out of the engine which will confirm the need to clean one set of injectors.

If all four of your refurbished injectors are all frozen, the odds of this occurring to two members here within as many weeks is astronomical. I've never heard of it before.

Are the injector shops using some new environmentally safe injector cleaner as required by some environmental agency?  Does this cleaner need to be flushed by the fuel within a short period to prevent damage?

Acetone springs to mind.  Other than being very flammable it is actually pretty benign, but long exposure will soften a lot of plastics. It is also relatively cheap.

Hessian wrote:Hi Inge K, I have not checked to see if the injectors work before putting them on the bike. A forum member let me borrow them as they are freshly refurbished, so we assume they would work...

The once famous television science presenter, Prof. Julius Sumner-Miller once said "the funny thing about the word assume... It makes an ass out of u and me"

Our older design injectors are highly prone to corrosion so without fuel running thru them for a while they could be fruzzed.... worth checking.
Even with fuel, water in the tank can be a problem, particularly if the engine is not run for some time.


There's some interesting reading here.
Google Search: Professional grade fuel injector cleaner

indian036 wrote:

K75cster wrote:

Kaptain Holister wrote:While not related to this problem, it's also important to understand that all injectors open and close at the same time, twice per engine revolution (4 times per cycle). It is only the duration of the injectors opening which is controlled by the FICU.

I thought that the injectors for 1 and 4 and then 2 and 3 as in 2 twins the spark is that way isn't the injection that way

Early injection systems operated as the Kaptain said. The most modern have sequential injection which means that injectors fire individually as the air is sucked into each cylinder. 

When the changeover happened is highly variable on brand and model of vehicle (car and bike), and I have no idea when BMW made this change, but certainly the Ks are well before.

Bill

Read something interesting over the weekend... apparently the Motronic (not the Jetronic) did have the capability to switch the injectors in pairs ie 2+3 and 1+4 but BMW chose not to utilise this feature for the later Ks. Does anyone know if this changed down the track?

OK, well I had the injectors cleaned and while the guy said my original set were dirty (and now work), the other set had one that didn't work at all.

Anyway, I went to put them back on the bike and one squirted fuel out of the rail, so I think the seals could be replaced as some of them a little a little iffy. Do we have a part number for those seals, or will most seals fit?

I just got these to do my K1100
http://www.ebay.com.au/itm/BMW-Fuel-Injector-Service-Repair-Kit-M3-E30-86-91-4cyl-/251914872976?

RicK G wrote:I just got these to do my K1100
http://www.ebay.com.au/itm/BMW-Fuel-Injector-Service-Repair-Kit-M3-E30-86-91-4cyl-/251914872976?

Does anybody know if they make a rebuild kit for the 85 K100 fuel injectors?

All you can do is clean them and put new O-rings and filters, they don't come apart for servicing.
A word of caution, don't put 12 volts power on them to check if they work. I use a 9 volt smoke alarm battery, 12 volts on them continuously will damage them.

You can get this injector kit from Repco here in Oz that suits the standard K100 #210 injector. I see no reason why it wouldn't be suitable for the K1100 injectors also. This kit is not suitable for 4 hole injectors tho.
Fuelmiser part# ISK-0500AX $13.60
contains 2 sets - filter, o-rings, bottom spacer and pintle cap.
Getting the filter out is the hardest thing but if you screw a self-tapper into the old filter you can grab it with a pair of pliers. There're youtube vids that show how.

OK, well we have definitive lift off. I got the new injector kit in the mail, so replaced all the o-rings etc and it's fired up twice easily.

At idle, it feels a bit rough, like the bike is a bit shakey (don't really know the right word), but revving it makes it all very smooth. Im doing an oil change this weekend and will take it around the block to scrape the surface rust off the rotors.

would have been effective to clean the injectors out with carbi cleaner ...and an ultrasonic bath before doing the seals and filters ///or at least exercising them with injector cleaner and a bit of pulsing them at the same time

they could get better over time ....but only if you start to use some fuel additive injector cleaner ....but in many cases the injectors still leak a little without the clean up process


good luck mate

Thanks mate, yeah they got professionally cleaned, but the guys at the shop don't do o rings etc. I thought it was weird, but hey

then ...a good long ride will be the deal ...burn all that gunk out ?

cheezy grin photo opportunity soon perhaps ?

Also, final question - where is the location for gearbox oil? I can't seem to find a picture or video or whatever. I've done an oil change, and the read drive oil is full (probably could be changed) but where does the tranny oil go?

the plug for the gearbox is right beside the alternator on the right hand side ...   just behind the sump cover




almost directly below on the under side is the drain


don't forget the bmw "c spanner " is the depth guage for the fill level ...or 116mm down from the unscrewed cap

good luck

Thanks for the photo. I thought it was that bolt haha.

So I've been doing laps around the carpark opposite the house and I can't lock up the front brake or rear. I havent replaced the pads and there was a lot of surface rust on the discs. I've bled the brakes, and the front certainly compresses etc, but no lockup. Its not an ABS model.

Anyway, some niggly little things, but should be getting a roadworthy on it soon. Very smooth engine

I don't think you really want the front brake to lock up, only under very severe circumstances and then it would require a lot of very hard braking. In this situation you'll need some skill to control the front end.
If you mean the brakes aren't grabbing and pulling you up quickly, you will probably find you'll need to get up to 60+kph and apply controlled hard braking to 'bed' the pads in after the rust has been worn off. Do this a few times.... carefully

Bleeding the brakes is good but if the bike has been sitting around for some time you would really want to replace all the brake fluid. That could be why your brakes aren't stopping well.

Must be great to finally ride that machine eh

I went through a bottle of new fluid and also did the same on the rear, so I just thought it would be grabbier. I dont think I've cracked the 60kmh at this point, simply because its not the open road 

But yes, definately a great feeling to hop on something other than the Harley. Soooooo different. There are two wheels and thats where the similarity ends!

The last cosmetic thing is one of the lugs has broken off on the side cover, so it won't stay on. I'll probably ghetto something up to fix that