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gpzoduibh
Big Brick Rider
Joined: 10 Aug 2007
Posts: 70
Location: Co. Meath Ireland
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 Posted: Thu Jul 03, 2008 3:35 am Post subject: Symptoms of a bad fuel pressure regulator ? |
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Hello again
following on from my temperature sender post , I checked it out last night and at the ECU connections its reading as it should air temp and water temp sensors showed similar readings when cold 3.01K for water and 2.96K for air and the water dropped to 790 ohms after a brief warm up , my next question for all you Guru's is the pressure regulator , I am getting popping on the overrun and my main misfire happens on throttle off and snap back on , the vacuum connection drops the fuel pressure when on the overrun , could this be sticking ? causing low fuel pressure when you open up again ? if I close the vac. connection and drive it will I do damage to test this theory ? If you had one of these fail what happened ?
As ever I await your replies oh wise ones 
Regards
Bill Black
_________________
1995 Grinnall Scorpion III(1990 K100 16v motor)
2010 KTM 450 EXC
Moto Guzzi V50 powered hovercraft !
1989 K100RS (8V) special edition
1974 Yamaha DT360
1972 Sanglas 400 T
1980 Yamaha XS110-Watsonian Palma sidecar
1966 Bridgestone 175 dualtwin
1980 BMW R100RS
1979 Bultaco sherpa T 350
1979 Yamaha DT175MX
1990 Honda XR250R |
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jarnbak
Mad Brick Rider
Joined: 18 Jan 2004
Posts: 85
Location: Helsinge,Denmark
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| Posted: Thu Jul 03, 2008 5:52 am Post subject: |
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The 16 valve k1/k100/k1100 dont have a vacum connection on the fuel pressure regulator.The k75/k100 6/8 valve with LE-jetronik has the connection. Try replace regulator with one from a k100 16v or k1100.
regards Palle. |
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gpzoduibh
Big Brick Rider
Joined: 10 Aug 2007
Posts: 70
Location: Co. Meath Ireland
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| Posted: Thu Jul 03, 2008 6:01 am Post subject: |
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if you go to : http://www.maxbmwmotorcycles.com/fiche/MainDiagrams.asp?mospid=47922 Fuel preparation system Diagram N0: 13-0522 it shows part No: 02 13531460451 pressure regulator
which is what I am talking about Palle .
Regards
Bill
_________________
1995 Grinnall Scorpion III(1990 K100 16v motor)
2010 KTM 450 EXC
Moto Guzzi V50 powered hovercraft !
1989 K100RS (8V) special edition
1974 Yamaha DT360
1972 Sanglas 400 T
1980 Yamaha XS110-Watsonian Palma sidecar
1966 Bridgestone 175 dualtwin
1980 BMW R100RS
1979 Bultaco sherpa T 350
1979 Yamaha DT175MX
1990 Honda XR250R |
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jarnbak
Mad Brick Rider
Joined: 18 Jan 2004
Posts: 85
Location: Helsinge,Denmark
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| Posted: Thu Jul 03, 2008 6:56 am Post subject: |
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sorry,my bad.I dont have one of these on my k11.Insted i have 13531464588 so maybe i will try one from a k1/k100 16v to see the diff.
Regards Palle. |
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Scott_Anderson
Site Admin
Joined: 05 Sep 2006
Posts: 3128
Location: Central Iowa, USA
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| Posted: Thu Jul 03, 2008 7:48 am Post subject: Re: Symptoms of a bad fuel pressure regulator ? |
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| gpzoduibh wrote: | my next question for all you Guru's is the pressure regulator , I am getting popping on the overrun and my main misfire happens on throttle off and snap back on , the vacuum connection drops the fuel pressure when on the overrun , could this be sticking ? causing low fuel pressure when you open up again ? if I close the vac. connection and drive it will I do damage to test this theory ? If you had one of these fail what happened ?
As ever I await your replies oh wise ones
Regards
Bill Black |
Here are a couple more snips for you.
Remove the throttle position switch and see what happens. I took mine off for good several years ago to eliminate a little burble in the throttle response. The bike will run fine this way. The switch only tells the FI that the throttle is fully closed or fully open. When fully closed and RPM's are above 2000, the FI computer shuts fuel to the injectors. Passing 2000rpm up and down on and off the throttle as on a tight road is where the burble I mention will be encountered. Removing the TPS clears this up. Also, at closed throttle and idle RPM there is some slight throttle enrichment. At full throttle the FI adds time to the length of the injector timing to increase the richness of the mixture. This functions somewhat like the accelerator pump in a carb plus the extra richness protects the engine at full throttle and max rpm in top gear when the engine is making maximum power and speed, as some of our German brothers will have opportunitied to ride like this to our great envy. In my case I have recalibrated the airflow meter to speed up throttle response so the overswing of the vane more than compensate for any full throttle enrichening I lost by removing the TPS, but also note my friend the former BMW R&D tech tells me they would routinely remove these TPS's to make the bikes ridable on the snow! These were tough dudes. You won't harm anything removing the TPS. If the problem goes away then relocate the TPS to the trash can and tape over the electrical connector. Problem solved.
My guess is your flat spot may be due to a too lean basic mixture. You need to check the CO percentage on an exhaust gas analyzer. For best driveability it should be around 2%, this will give nice throttle response at the expense of an MPG or two. CO is adjusted on the air flow meter with the bike fully warmed and running. There is a difficult to reach rubber plug on top of the air box' right forward corner. Remove the plug and a 5mm allen wrench will turn the bypass screw on the airflow meter itself. Clockwise to richen the mixture and anti-clockwise to make it leaner. Be patient, changes do not show up on the gas analyzer for several seconds. Be patient and let the reading stabilize before turning the bypass screw more.
K-10016V's ( or K-100/2 )and K-1100's with Motronic must have their TPS and it must work. It is a completely different type of TPS than you have on a K-75 or K-100/1. The FI needs to know throttle position and crank position to generate a correct pulse timing. On earlier L-Jetronic two valve per cyl bikes like the K-75 the vane in the air flow meter combined with crank position info generates the pulse timing.
Make sure the throttle position switch is correctly positioned. It should be set so that a click can be heard as the throttle leaves the stop. The switch's major function is to tell the FI that the throttle is closed. The FI will stop the injectors from operating at closed throttle when rpm is above 2000. If the TPS is set incorrectly you can get a big boom sometimes when operating the bike from closed to part throttle repeatedly.
Good luck.
_________________
Ride safe.
1997 K1100LT 0302488
2017 FLHTK Ultra Limited
Garmin StreetPilot 2820
Garmin Zumo 550
Garmin Zumo XT
"One who does not ask questions is ashamed to learn" Danish proverb
1995 K1100LT 0302044(R.I.P.)
1997 R1100RT ZC62149(sold) |
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rover759
Big Brick Rider
Joined: 30 Jul 2007
Posts: 68
Location: Houghton Regis,UK
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| Posted: Thu Jul 03, 2008 3:52 pm Post subject: |
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 I used to do that deliberately in tunnels with my K75S  |
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