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[help wanted] BMW motronic guru needed


popov1100

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Hi everyone,

 

I'm new on this forum, I'm french, and i'm sorry, my english is not very good.

 

I've got a little web site about bmw motorcycle

http://popov1100.ath.cx:85

 

but today i need some help

 

my R1100GS was stolen at 162000km (100 000miles)

so i've bought a brocken engine french police R1100RT

 

this is a 1998 r1100rt

 

picture here :

 

http://popov1100.dyndns.org/cpg/thumbnails.php?album=30

 

the 1998 motor was rebuild with some 1995 parts

cylinders

cylinders head (with big valves)

barrels

and camshafts.

 

all this 1995 parts came from and 44000km R1100GS motor.

 

so I've go an R1100RT bike with R1100GS motor.

 

r1100rt have differents throttle body than r1100gs, the angle is not the same 5° for GS, 10° for RT

 

this RT have not catalytic, and not lambda, there is CO Potentiometers

 

but here is my probleme :

 

when i do 0=0 procedure

every things works fine, but the idle is near 1800rpm

the bypass screw are inefective, close or open this is the same. the tps is set to .370mV

 

no error for the motronic

 

the co is set à 2%, the bike is un-ridable....

 

if i do an other 0=0 procedure, but instead of .370mV, i set the idle position when the tps is at .230mV, then the idle is near 1100/1200 rpm

the bypass screw are effective.

1/2 turn open give 1100rpm

1 turn open give 1200rpm

 

but then the co pot is not fully effective, the co jump from .5% to 2.6% without any values beteen.

(i'm thinking my co pot is deffective, i've ask for a new one to my dealer)

 

but the question is :

what value in mV shall we use to do 0=0 precedure on R1100GS

is it .370mV too.

 

or shall I put a good idle rpm about 1100

with stop screw and bypass screww à 1.5 turn

and after ty idle is set, move tps to .370mV

without moving the two stop screw ?

 

is it clear ? i hope you understand my problems

 

regards

 

JMD

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ShovelStrokeEd

Welcome,

I'm not a guru by any means but you are not far off the track here.

 

You should just get the idle speed you need with the stop screws and then set the TPS voltage by loosening the screws holding the TPS and turning that to get the 0.370 volts. When you have done that, you can now attempt to adjust the CO pot. You may find yours is OK or it needs replacement as you indicated. I wouldn't worry too much about an absolute value for the CO, adjust for best driveability although, the world will thank you if you can bring it into specification.

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yes, i've thinked about it

 

the intake manifold are new

well mounted, and not leaky

i've tested with "start pilot" sprayed on the two manifold

 

i've all ready test for a leaky cylinder head.

with crack detection spray. no problem

 

http://popov1100.dyndns.org/cpg//displayimage.php?pos=-3227

 

i've think the main problem is caused by the difference idle angle between GS and RT throttle body (5° and 10°)

 

does anyone make 0=0 procedure on a R1100GS ?

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Welcome,

I'm not a guru by any means but you are not far off the track here.

 

You should just get the idle speed you need with the stop screws and then set the TPS voltage by loosening the screws holding the TPS and turning that to get the 0.370 volts. When you have done that, you can now attempt to adjust the CO pot. You may find yours is OK or it needs replacement as you indicated. I wouldn't worry too much about an absolute value for the CO, adjust for best driveability although, the world will thank you if you can bring it into specification.

 

thanks for you advice,

i'll try this

towmorrow, i'll have the new co potentiometer

i'll try to tune it about 2% (generaly this give best drivability).

if is's not perfect, i'll set the tps at 0.370mV with out touch stop screw

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JMD,

Your English is just fine. smile.gif

 

I have basically the same engine (08/95 but it's an R1100RT,no CAT and no CO Pot).

 

I would suggest you remove the CO Pot for now. 2% CO is a good value to set it at, after you do the 0=0. You can measure the CO Pot with an Ohmmeter to see if the value of resistance changes in a linear fashion. If so, it's good.

 

I would go back and close the Idle Bleed screws fully, close the throttle plates and start over. With the left side throttle stop screw 'just' touching, loosen the TPS and set it to 0.010V (make sure all the slack is out of the TPS junction in a clockwise direction)and then open the left throttle plate till you see 0.370 between pins 1&4. Next, set the right throttle plate to about the same opening and start the engine and warm it up.

With a TwinMax or Carb Stix attached, set the RIGHT side to match the left but do not change the left throttle stop. The idle will be low at this point but you don't care, yet.

After you have the throttle plates balanced left to right, use the idle air bleed screws to get 1,100 RPM.

After you are all done and happy with the idle, you can reattach the CO POT and adjust for 2% CO. You 'may' have to adjust the bleed screws to keep it around 1,100 RPM.

 

I've done a LOT of 0=0's but never with a CO pot attached.

 

Mick

Tucson

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JMD,

Your English is just fine. smile.gif

 

thanks

I have basically the same engine (08/95 but it's an R1100RT,no CAT and no CO Pot).

 

not exactly the same, cylinder are the same,

cylinder head are the same, too

 

but pistons and camshaft are differents (GS one)

throttle body are differents to....

 

but i've got RT throttle body.

 

I would suggest you remove the CO Pot for now. 2% CO is a good value to set it at, after you do the 0=0. You can measure the CO Pot with an Ohmmeter to see if the value of resistance changes in a linear fashion. If so, it's good.

 

I would go back and close the Idle Bleed screws fully, close the throttle plates and start over. With the left side throttle stop screw 'just' touching, loosen the TPS and set it to 0.010V (make sure all the slack is out of the TPS junction in a clockwise direction)and then open the left throttle plate till you see 0.370 between pins 1&4.

 

0.370 mV between the rear pin and the battery ground; it is the same i think ;-)

Next, set the right throttle plate to about the same opening and start the engine and warm it up.

With a TwinMax or Carb Stix attached, set the RIGHT side to match the left but do not change the left throttle stop.

 

yes, i've got a twinmax

The idle will be low at this point but you don't care, yet.

After you have the throttle plates balanced left to right, use the idle air bleed screws to get 1,100 RPM.

After you are all done and happy with the idle, you can reattach the CO POT and adjust for 2% CO. You 'may' have to adjust the bleed screws to keep it around 1,100 RPM.

 

I've done a LOT of 0=0's but never with a CO pot attached.

 

Mick

Tucson

 

do you ever done 0=0 on R1100GS ?

 

ok, i'll try this procedure without the CO potentiometer.

thanks for this indication

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Popov, old fart! grin.gif

 

Isn't that enough that you polluted each and every french BMW forum with your RT-P problem. wink.gif

 

Now you jump over the Pont and start annoying people here. dopeslap.gif

 

Isn't there any place in this world where I can get some peace of mind? lmao.gif

 

BTW Popov did an outstanding job on his Frankenstein RT-P.

 

I would just screw the stop screw down until idle is perfect (and balanced) and then leaving everything else alone, rotate the TPS until I get again 385 mV.

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it's look like the bmw world is very small...

 

happy to see your here.

 

i'll do that, soon, i'm waiting for a new co potentiometer, to be sure (easy to test with the CO analyser).

 

finaly, when Willy (my R1100RT) works fine, i'll be a motronic guru too dopeslap.gifdopeslap.gif

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do you ever done 0=0 on R1100GS ?

 

ok, i'll try this procedure without the CO potentiometer.

thanks for this indication

 

Yes,

I've done the 0=0 on several R1100GS's

 

Mick

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Stop the lights !! Is that your garage, here?

 

normal_DSCF0069.JPG

 

If so, never mind the RT - is that the wheel of a Yamaha GTS1000 I see behind it? If so, I think that's infinately more interesting that than any 0-0 problem ! grin.gif

 

Oh, I like the 911 too, btw.........and the Duc on the lift.........

 

Isn't it terrible to be an anorak? wave.gif

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pff, it's not exactly a 911, it's a 993

 

it's a GTS too

and the ducati, is a multistrada with a 999 engine

a little proto (not ended)

 

but, this is not my garage , this is a very good friend of

mine frown.gif

 

but i can do mechanic in his garage when ever i want

there is a lot of good tool, and a fuch dyno.

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hi

 

yesterday evening i've done a new 0=0

1.5 turn bypass screw openned

the idle run stabilized to 1100 rpm (when engine is warm)

 

then i've read 194mV at the TPS

 

this value seem good for my r1100rt throttle body

10° opening -> standart value 370 to 400mV

5° opening -> 194mV

closed -> 8mV

 

i'dont no if the tps is lineary, but this work

 

after this, without touch the stop screw,

i've manualy set tps to 350mV

 

all the procedure was done without CO potentiometer

 

a test ride is good, engine is very confortable to ride,

no problem (without co pot).

 

now i'll put the CO potentiometer en set CO value to 2%

 

thanks every body for your advice

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  • 5 months later...

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