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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: BobZ(IL) on August 10, 2019, 07:13:16 PM

Title: Fuel Issue
Post by: BobZ(IL) on August 10, 2019, 07:13:16 PM
Fresh gas, new fuel filter, bike may start and idle for about a second then die. Fuel pump seems to pump like crazy. Next?
Title: Re: Fuel Issue
Post by: daveson on August 10, 2019, 07:41:54 PM
Overfueling usually from a faulty temperature sensor. Can you hear the injectors clicking with the aid of a screw driver?
Title: Re: Fuel Issue
Post by: Laitch on August 10, 2019, 08:18:25 PM
Fresh gas, new fuel filter, bike may start and idle for about a second then die. Fuel pump seems to pump like crazy.
How was it running before the new fuel filter was installed? Pump like crazy? Verify the correct orientation of the filter, that all hose clamps are tight and that fuel actually is coming at pressure from the hose that attaches to the rail when the starter is cranked. Check that the battery clamps are tight and that the battery negative cable is tightly attached to the transmission. 
Title: Re: Fuel Issue
Post by: Scott_ on August 10, 2019, 10:43:54 PM
Hey there Bob, how's the spark. Being a '93, don't forget the ignition amp module.
TPS, within adjustment?
Title: Re: Fuel Issue
Post by: BobZ(IL) on August 10, 2019, 10:47:55 PM
Fuel pumps properly whenever a start is tried, however, I have no way to measure actual pressure. Engine just quit at highway speed. Need a little more explanation on checking injector click. Listen while attempting start? Thanks for the responses.
I'll pull a plug to check for flooding.
Title: Re: Fuel Issue
Post by: BobZ(IL) on August 10, 2019, 10:53:22 PM
Hey Scott, hope you are doing well. Is the ignition amp module that part we put heat sink paste on? TPS adjust by turning engine over at full throttle? When I checked the spark on number one it seemed a little lame.
Title: Re: Fuel Issue
Post by: Scott_ on August 11, 2019, 07:00:10 AM
Hey Scott, hope you are doing well. Is the ignition amp module that part we put heat sink paste on? TPS adjust by turning engine over at full throttle? When I checked the spark on number one it seemed a little lame.

Yes, the amp module is what gets the heat sink paste.
The TPS is set with a voltmeter, ignition on-engine off.

from here: http://www.k11og.org/forum/viewtopic.php?t=2110

Throttle Position Sensor (TPS) Test:
To test the TPS
Ignition OFF, Ground Pin #3 and monitor Pin #1 with a 12V LED (+lead to Battery + and -lead to Pin#1). Ignition ON, Engine OFF (Pin #3 should remain grounded during this test)
The Test LED will be ON at idle (closed throttle) and OFF just above idle. You should also be able to watch the temperature warning lamp on the tachometer blink ON at idle and OFF just above idle.
Pin #1 should be Low at idle and High just above idle. In other words, if you are measuring from ground to Pin #1 with a voltmeter, Idle should be close to 0 Volts and just above Idle should be close to 12 Volts. (This test also works for Oilheads (1994-2001) with Motronic 2.2 Engine control Units but since there is no temperature warning lamp, you must use either a voltmeter or a Test LED as described above).

NOTE: Measuring the voltage between pins 1 and 4 at the TPS connector should indicate
0.375 Volts at the idle setting (closed throttle) with ignition ON engine OFF.
Snap the throttle open/closed a few times to ensure a consistent reading. To adjust the TPS, loosen the two screws slightly and rotate the TPS until the temperature warning lamp (or the Test LED) 'just' comes ON at idle and goes OFF just above idle. If you are using a voltmeter, adjust the voltage to 0.375 at idle (closed throttle). This voltage MUST remain below 0.400 Volts at idle.
Title: Re: Fuel Issue
Post by: daveson on August 11, 2019, 05:20:18 PM
Try the other suggestions first. I was jumping the gun as I took "pumps like crazy " to mean overfueling. Later you say pumps OK.
Title: Re: Fuel Issue
Post by: Laitch on August 11, 2019, 05:27:14 PM
Fuel pumps properly whenever a start is tried, however, I have no way to measure actual pressure. Engine just quit at highway speed.
Your opening post didn't mention that it ever made it to a highway. How did you determine the fuel "pumps properly"? Did you disconnect the delivery hose at the fuel rail?
Title: Re: Fuel Issue
Post by: BobZ(IL) on August 12, 2019, 05:00:30 PM
Try the other suggestions first. I was jumping the gun as I took "pumps like crazy " to mean overfueling. Later you say pumps OK.
Pulled a plug again to check spark. Strong. Plug looks damp. Had this problem before but can't remember cure. Will try heat sink first, then consider temp sensor. I've replaced sensor before and repasted the module previously but don't remember which solved the problem.
Title: Re: Fuel Issue
Post by: BobZ(IL) on August 22, 2019, 09:08:06 PM
Bike is throwing an 1133 fault code indicating a signal problem from Hall Sensor. Thanks for the suggestions on things to look for.
Title: Re: Fuel Issue
Post by: alabrew on August 23, 2019, 06:06:24 PM
Is the motor running when you get this code?

Have you looked into the gas tank to see if maybe a hose popped off inside the tank or is split, not giving enough pressure?
Fairly common on the k12lt, especially when they just stop when you are riding.
Title: Re: Fuel Issue
Post by: BobZ(IL) on August 23, 2019, 09:30:47 PM
alabrew,

Bike doesn't start, no fire on 2&3 which the code indicates. Fuel pressure appears adequate but I have no way of measuring.
Title: Re: Fuel Issue
Post by: Laitch on August 24, 2019, 06:07:46 AM
Bike is throwing an 1133 fault code indicating a signal problem from Hall Sensor. Thanks for the suggestions on things to look for.
Bike doesn't start, no fire on 2&3 which the code indicates. Fuel pressure appears adequate but I have no way of measuring.
There is no point in running a code check if the codes can't be believed. Check the function of the Hall sensors. One might be faulty.
Title: Re: Fuel Issue
Post by: BobZ(IL) on September 03, 2019, 09:21:28 PM
Replaced the HES. Bike started right up, idled  and reved up smoothly and sounded great. Will test ride tomorrow after buttoning up the bodywork.
Thanks everyone for the suggestions and feedback.
Title: Re: Fuel Issue
Post by: ScooterNSticks on September 03, 2019, 11:20:41 PM
Tell me I'm dreaming and a Hall Sensor doesn't cost $400.
Title: Re: Fuel Issue
Post by: volador on September 04, 2019, 12:01:45 AM
Tell me I'm dreaming and a Hall Sensor doesn't cost $400.
You're not dreaming and short by hundred+. You'll probably be needing a new HES or Bosch fuel pump soon.

K75 HES Max BMW (https://shop.maxbmw.com/fiche/PartsSearch.aspx?&searchtype=undefined&parts=12111459049)

Part Number     Description   lb   Each
 12111459049     IGNITION SENSOR   0.30    $519.10

K100,K1100 HES Max BMW (https://shop.maxbmw.com/fiche/PartsSearch.aspx?&searchtype=undefined&parts=12111459033)

Part Number     Description   lb   Each
 12111459033     IGNITION SENSOR   0.30    $631.29
Title: Re: Fuel Issue
Post by: Martin on September 04, 2019, 12:52:27 AM
Your local electronics shop should be able to supply you with them they run to around $25.00 Au each in OZ. Part no is HKZ 101 although they can be found under other part numbers from various sources. I just deleted incorrect EME information.
Regards Martin.
Title: Re: Fuel Issue
Post by: Chaos on September 04, 2019, 02:12:57 AM
Tell me I'm dreaming and a Hall Sensor doesn't cost $400.

I'm still on my original HES and fuel pump, 200,000 miles.  But I have spares. 
Title: Re: Fuel Issue
Post by: Laitch on September 04, 2019, 08:01:24 AM
I'm still on my original HES and fuel pump, 200,000 miles.  But I have spares.
Well, aren't you the lucky beemer biker. :twothumbsupp
Title: Re: Fuel Issue
Post by: ScooterNSticks on September 04, 2019, 08:51:29 AM
You're not dreaming and short by hundred+. You'll probably be needing a new HES or Bosch fuel pump soon.

K75 HES Max BMW (https://shop.maxbmw.com/fiche/PartsSearch.aspx?&searchtype=undefined&parts=12111459049)

Part Number     Description   lb   Each
 12111459049     IGNITION SENSOR   0.30    $519.10

K100,K1100 HES Max BMW (https://shop.maxbmw.com/fiche/PartsSearch.aspx?&searchtype=undefined&parts=12111459033)

I hope not.  Both were changed by the previous owner about 3000 miles ago.  I'm expecting nothing but oil changes and tires for the next 20K miles.  Glad I'm not superstitious otherwise I would be thinking the K75 is catching fire right now in the garage.

Part Number     Description   lb   Each
 12111459033     IGNITION SENSOR   0.30    $631.29
Title: Re: Fuel Issue
Post by: Martin on September 04, 2019, 05:09:10 PM
Thanks Laitch I deleted the incorrect part number.
Regards Martin.