K100 runs like %@&*

[cycle_guy]

This shade tree mechanic's patience is getting thin I'm almost ready to take it to a real BMW mechanic who has all the magic diagnostic tools I don't. Trouble is my nearest dealer is a 100 miles away and my pride is at stake here.
So, I started with a not running K100 with 13K miles that had sat for 15 years. Currently engine starts barely, no throttle response, little power, like it's running on less than all four. I started by cleaning of all electrical connections and dielectic grease applied then started swapping out parts each time checking for improvement. Cleaned fuel tank, compression test good, All plugs firing, All injectors spraying, Checked for improvement after each of the following parts was swapped out. New or good used replacement parts: plugs and wires, coils, air filter, battery, ignition unit, fuel injectors, fuel pump, fuel filter, jetronic unit, throttle position sensor, fuel pressure regulator, all new fuel & vacumn hoses. The only engine fuel/electric part I haven't changed out is the Hall Effect Sensor that I ordered yesterday. Somehow I don't think this is the problem either but I'm running out of options and money.
Does anyone know of any other methods of diagnosing this sick puppy.:cry

[roy]

Is the mass air flow sesor operating correctly? On my K100 it is located in the air filter box cover and a real PITA to remove and install. Possible sitting 15 years this is not functioning?

Have you tried checking the timing? It is pain but you can shine a timing light through the front tire and see the marks. I don't know if that would give you the lack of throttle response or not.


About the only items I can think of that you didn't mention.

Good Luck & remember Stubborness overcomes common sense...

Roy

[cycle_guy]

Thanks Roy, I did check the mass air flow sensor to make sure it is free moving and not jammed and it seemed okay.
The timing light is a possibility. I have turned the hall sensor slightly each way with no effect.

[cayuse60]

Since you report fuel and fire (spark) I would be looking closely at the ignition and valve timing . Have you followed the PIA igniton timing procedure in CLYMER? If nothing else it will get you in the ballpark. You do not need a dial indicator for TDC...I use my sense of feel using a 6 in. 1/4 in. drive socket extension in the spark plug hole and a volt/ohm meter.
Hope this of some basic help:) ---tim

[cycle_guy]

Tim
No, I didn't do this test because I marked and didn't change the original position of the Hall Sensor. But I'm grasping, so I'll check the timing via the Clymer procedure. Thanks for your help.

[kioolt]

This is a long shot but since the bike sat for 15 years it could be possible that something has crawled down the exhaust system and set up home. It may be worth while to check the exhaust for restriction.

[cycle_guy]

Thanks for the idea. I've had the exhaust off and dissassembled cleaned and back on. I've gotten a lot of old bikes running that didn't run for one reason or another, but this one is a real challenge.

[deilenberger]

Thanks for the idea. I've had the exhaust off and dissassembled cleaned and back on. I've gotten a lot of old bikes running that didn't run for one reason or another, but this one is a real challenge.
Some elementary diagnostics questions (you seem to be flailing - more on that later..):

1. What's the compression? If it was sitting that long - good chance the rings rusted up and aren't sealing well, or the valve guides could have gotten gummed up and the valves aren't closing properly.

2. What's the fuel pressure?

3. What do the injector spray patterns look like?

4. What are the readings from the engine temperature sensor as measured at the computer connection plug?

5. How do the plugs read when you pull them out?

6. What's the end to end resistance of the ignition wires? (even the replacement ones you installed.. if used - there is no guarantee of them being good..)

7. Have you checked for flashover of the ignition wires and ignition coils? (Ditto)

Now - on "flailing" - it's a term I've used for random replacement of parts.. without any particular reason to replace them. Please don't be insulted, but what you've done so far has that appearance. If you replace enough parts sooner or later you'll solve the problem, and it will be the last part you replace that does it - but it's an awfully expensive way to troubleshoot.

In order to run the bike needs:

o - air
o - fuel
o - spark
o - compression
o - a place for the waste products to go

One of these is the problem, answering the questions I asked will help narrow down your search. I much prefer to figure out what part is at fault and have the first and last part I replace fix the problem, but you'll only do that by diagnosing each system first..

HTH..

[Motor31]

Just because the "gate" on the airflow meter box moves does not mean the temperature sensor located in it is functioning. You'll need the diagnostic info and a way to measure the resistance it is putting out. It is not going to be in a Clymer or Haynes manual. It's in the BMW shop manual. IIRC there are 3 temp sensors, air, coolant and oil. If any are not working it will cause the bike to either not run or run very very badly. The air sensor went out on mine and it was the push I needed to finally get the bike I have now.

[roy]

Just out of curiosity, what sensor tells which injector to fire and and at the correct time?

Is there a crank or cam position sensor for this?

Thanks

Roy

[breyfogle]

I believe that the Hall sensor on the front of the block, above the water pump, tells the FI computer the crank position and the FI computer figures out when to open the injectors.

[deilenberger]

I believe that the Hall sensor on the front of the block, above the water pump, tells the FI computer the crank position and the FI computer figures out when to open the injectors.Yup.. they do timing, and the injectors are fired based on timing. They live behind the T shaped cover on the left side of the front engine cover (looking at the front of the engine) - and they're in line with the crankshaft.. (the oil/water pump are driven by the output shaft - which is different..)

[cycle_guy]

Don and others
Thanks for all you're input. I admit to flailing at the problem. I'm a shade tree mechanic without sofisticated equipment and shop manuals trying to figure this out and learning along the way.
Here's a question. Is there a way to set the Hall Effect Sensor timing without a BMW Ignition Tester part # 12 3 650 and BMW Test Lead part # 12 3 651 that are listed in the Clymer manual. I understand all the 0.009 in. BTDC stuff. Can a volt/ohm meter or timing light be used? If so exactly how.

[cayuse60]

Don and others
Thanks for all you're input. I admit to flailing at the problem. I'm a shade tree mechanic without sofisticated equipment and shop manuals trying to figure this out and learning along the way.
Here's a question. Is there a way to set the Hall Effect Sensor timing without a BMW Ignition Tester part # 12 3 650 and BMW Test Lead part # 12 3 651 that are listed in the Clymer manual. I understand all the 0.009 in. BTDC stuff. Can a volt/ohm meter or timing light be used? If so exactly how.

http://www.ibmwr.org/ktech/k-bike-ignition-timing.shtml

Try this link for reference to checking timing on a running machine. There are two links referred to within the link that will give you additional info.:thumb
---tim

[sgborgstrom]

Any chance you got the plug wires back on in the wrong order?

[cycle_guy]

Steve
Brand new plugs and wires and I have tripple checked that all are in the right order.
Tim
Thanks I'll give that link a try.

[cycle_guy]

Tim and others
I tried the timing light method described in the link. Wow! Is it painful to shoot the timing light in that little hole and be able to see the marks, even with a mirror. Trouble is the front wheel and forks are in the way of being able to see well. Plus I burnt the timing light wires from the battery on the exhaust.
I gave it up on the first try, but plan to go back and try it again in the next few days.

[deilenberger]

Tim and others
I tried the timing light method described in the link. Wow! Is it painful to shoot the timing light in that little hole and be able to see the marks, even with a mirror. Trouble is the front wheel and forks are in the way of being able to see well. Plus I burnt the timing light wires from the battery on the exhaust.
I gave it up on the first try, but plan to go back and try it again in the next few days.Using the mirror is really the trick to doing it.. and yeah - I've burned a few wires on the exhaust until I learned to droop them over the end of the handlebars..