My '99 R1100SA, 96K, seems to need a FOURTH Motronic unit. Symptoms start out as what seem to be a fuel delivery problem, loss of power,poor idle, but intermittent...after 2-3 brief episodes it'll completely fail, but still allow the bike to run, although very poorly. Bad acceleration, stalling when you let off on the gas etc...no codes in diagnostic mode at dealer(s). They recently swapped the throttle position sensor and replaced the current Motronic unit with the second one I bought last summer, this helped, cured 95% of my ills, but still ran poorly(surging)at low speeds, fine above 4000 rpm though. I've yet to be convinced that I've ruined 4 motronic units, and there seems to not be any ACCURATE test of the units. Anybody have any help/ideas? Voltage regulator is OK, fuel pressure is OK. Gimme some ideas before I'm broke, these things are expensive...thanks, Rex Gary
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Motronic Issues
- Thread starter WETDOG
- Start date
K
karasek
Guest
Four Motronics!!?? If they used your second one and with a new TPS and all was well (for awhile I gather), then I would suspect the motronic isn't the issue. Assuming the second one was considered bad and had to be replaced by a third.
How many dealers (mechanics) have tried solving this problem?
After replacing the motronics, does it fix the problem. How long does it go before it goes bad?
Rarely hear about motronics going bad. That just doesn't seem right.
How many dealers (mechanics) have tried solving this problem?
After replacing the motronics, does it fix the problem. How long does it go before it goes bad?
Rarely hear about motronics going bad. That just doesn't seem right.
Motronics units
Rex, do you have any friends that are really into fixing circuit boards. The hands on type who can sit down with a circuit board and draw you a schematic. If you do they may be able to help pinpoint which component in motronic unit is failing and possibly give you some ideas on where to start looking for what would cause this unit to fail.
You already have covered the obvious with voltage reg, fuel pressure etc. now comes the
.
Good luck
Rex, do you have any friends that are really into fixing circuit boards. The hands on type who can sit down with a circuit board and draw you a schematic. If you do they may be able to help pinpoint which component in motronic unit is failing and possibly give you some ideas on where to start looking for what would cause this unit to fail.
You already have covered the obvious with voltage reg, fuel pressure etc. now comes the
.Good luck
With a new motronic unit it'll run great for 20,000 miles or so then start to act up....it'll suddenly go rich for a few minutes and then fine for another week or so...then wham....full rich, barely rideable, limp home and get it to the shop....had a really competent mechanic diagnos the 2 motronic units. Recently a new single brand BMW dealership opened in the Cleveland area where I'm at. They've a new mechanic from Brevard BMW I believe....he's supposed to be Batman when it comes to BMWs....he assured me the TPS was in fact bad, replaced it and it took away 80% of problem, but it's still not right. It's going rich so we can eliminate a air leak in intake side...he tested the Hall switch yesterday. It tested good the first time, bad the second time and good the third time. At 260+ pesos it better fix it...this is getting really expensive now. Looks now like the 2 motronics I replaced were'nt bad. I had the second one in last week and it ran fine then it started running funny , switched to the original monday and it ran fine at the shop....GRRRR. Tuff to find when it's not doing it..
Is it at all possible that you have a very bad case of the surging and since it is a sportier bike that it is more noticeable? I am just asking since you are saying that it goes rich and then weak. I had a similar condition on my GSA and I was advised on this site to get a Techlusion T259 and it cured the whole problems for me. I am sorry in advance if we are talking about different levels of the problem...
This bike NEVER surged from day one.......except when things go bad....if you keep your valves properly adjusted, throttle bodies synch'd, Throttle bodies adjusted to your TPS they should'nt surge, mine never did...me thinks everything is pointing to the Hall sensor...maybe 96K + and it's been exposed to all weather. I ride daily until they spread salt here in Ohio, start up in early spring...maybe it's giving up...pretty cruddy behind that cover last time I swapped my poly V belt...
Ahhh I see. Well what you say makes sense then. Now that you explain that I remember reading an article in one of the ON mags earlier this year about how a guy changed out the Hall sensor because of the bike cutting out in the rain. The article went into great detail about how to do it...very interesting indeed.
On another note of the surging, when mine began surging I went through the valves and all the stuff recommended to check even the zero=zero TPS and it was better but still persisted...the Techlusion really balanced the fuel supply to both TBIs and the problem vanished now. Obviously this is not your issue though. Thanks for the reply as I will tuck that thought in my head in case I get the same stuff happen. Good luck,
Andy
On another note of the surging, when mine began surging I went through the valves and all the stuff recommended to check even the zero=zero TPS and it was better but still persisted...the Techlusion really balanced the fuel supply to both TBIs and the problem vanished now. Obviously this is not your issue though. Thanks for the reply as I will tuck that thought in my head in case I get the same stuff happen. Good luck,
Andy
You jogged my memory on the cutting out in the rain thing....a few years ago I had that happen to me in a heavy, heavy downpour.....just thought it might have been the side stand switch .....but later on after the rain it persisted for a few miles the next day after leaving the motel....hmmmm...
Hi LDS and yes those were the symptoms experienced by the autor of that article on both his bike and his wife's, and in both cases the rain or water was a key variable. Both of thise machines had higher mileage and one of the things I found interesting was I am constantly looking out for what is ahead for the bike as the mileage gets to thise levels...and that I can hinestly say is as bad as it gets. It is worth mentioning too that I remember the article well enough that the author also did tests on the Hall switch and found them to be okay but heat would obviously change things with expansion etc and then water seeps into places it should not be too..lol. Good luck
C
CustomSarge
Guest
Something is REALLY ODD here...
Motronic engine controllers will put up with a LOT of crap without failing. Having said that, I know of 2 it won't:
1> Corrosion/oxydation in connectors (hall, tps, temp sense intermittents etc), groundings of any & all. Never seen it cause damage, just runs bad.
2> Ignition coils not well grounded or loose. Can easily fry unit from back EMF. Also applies to disconnected plug wires, but not as severe.
I just had a "dry" Motronic connector give me fits on a K bike. Around 10 miles out, just hitting op temp, it would fuel starve until quitting. I swore (a lot) that it was fuel flow, scrubbed the connector with wd40; all ok.
LDSRider, I could checkout a unit for damage, given that it's still bad after the real problem is found. Been designing uProcessor stuff >20yrs. Good Hunting... <<<)))
Motronic engine controllers will put up with a LOT of crap without failing. Having said that, I know of 2 it won't:
1> Corrosion/oxydation in connectors (hall, tps, temp sense intermittents etc), groundings of any & all. Never seen it cause damage, just runs bad.
2> Ignition coils not well grounded or loose. Can easily fry unit from back EMF. Also applies to disconnected plug wires, but not as severe.
I just had a "dry" Motronic connector give me fits on a K bike. Around 10 miles out, just hitting op temp, it would fuel starve until quitting. I swore (a lot) that it was fuel flow, scrubbed the connector with wd40; all ok.
LDSRider, I could checkout a unit for damage, given that it's still bad after the real problem is found. Been designing uProcessor stuff >20yrs. Good Hunting... <<<)))
Sarge, Finally some real help on my woes...thanks for the ideas... Did I read you correctly that you could test these Motronics on a bench somehow?? I suppose I could switch 'em one at a time to test 'em, but on a S they are a pain in the rear to get to easily, Seems when they start assembly of a "S" they start with a motronic on some conveyor belt and start bolting stuff to it to create a motorcycle....really tuff to get to in a hurry....12-15 tiny fairing screws, air snorkels, hidden tank mounting bolts, misc. tie-wraps etc...if I get it running OK I'm just gunna leave it alone and swap 'em this winter maybe...
C
CustomSarge
Guest
Brass tacks time...
I can't test a unit in operation, unless I put it on my bike (usually a bad idea). I was referring to visual inspection on a known bad unit (for toasted components), ie after the real problem has been nailed down.
What piques my curiousity is that each "new" unit works well for some span of time. I thought you mentioned putting back a "failed" unit and it worked fine for a time. This redresses the "corrosion/intermittant contact" issue. Some of this is going to suck, because it's part of the discovery phase; that you have your previously failed units, swap them out cyclically and see if ANY if them are really bad.
On your model bike, you'll probably have to make some accomodations for kinda "grafting" the unit on. I'm sorry for this, but in order to isolate the problem, it's important to know that if ANY processor unit behaves initially, then devolves; is there a pattern? In rereading this, it still stinks of thermal/connector goofys.
Dumb question: have all relevant (or not) engine connectors been scrubbed & sprayed? (take wd40, open connector; spray; close connector [repeat 3-4 times])
This one ain't easy, we need more info to set the crosshairs... <<<)))
I can't test a unit in operation, unless I put it on my bike (usually a bad idea). I was referring to visual inspection on a known bad unit (for toasted components), ie after the real problem has been nailed down.
What piques my curiousity is that each "new" unit works well for some span of time. I thought you mentioned putting back a "failed" unit and it worked fine for a time. This redresses the "corrosion/intermittant contact" issue. Some of this is going to suck, because it's part of the discovery phase; that you have your previously failed units, swap them out cyclically and see if ANY if them are really bad.
On your model bike, you'll probably have to make some accomodations for kinda "grafting" the unit on. I'm sorry for this, but in order to isolate the problem, it's important to know that if ANY processor unit behaves initially, then devolves; is there a pattern? In rereading this, it still stinks of thermal/connector goofys.
Dumb question: have all relevant (or not) engine connectors been scrubbed & sprayed? (take wd40, open connector; spray; close connector [repeat 3-4 times])
This one ain't easy, we need more info to set the crosshairs... <<<)))
B
BOKRIJDER
Guest
Motronics
Sarge is on the right track, I'll expand a bit on his advice. Twenty years as an aircraft mechanic/electrician makes this scenario very familiar. I'd bet a free lunch that you have a wiring harness or connector problem. Disconnect every connector in the fuel system and inspect it carefully with a magnifying glass. Check for corrosion, bent pins, and deformed sockets. Corrosion can be in the form of a translucent film or slight graying of the components. Spray down with a dedicated connector cleaning chemical. LPS makes a contact cleaning product. A slightly bent pin will distort and enlarge the mating female socket. As a result the socket will not have the proper surface contact area or surface pressure. A damaged socket may have happened years ago and caused be a component which was long ago removed. If such a connector is disturbed as in unplugging and reinserting it will work for a while until corrosion again sets in or vibration causes the contact surface pressure to drop to the point that resistance goes up.
If this turns up no smoking gun move on to the next step. This becomes a bit more difficult, check each individual wire run for continuity at the corresponding connector end. rig up an ohm meter. Tug on the wire at the connector, bend the harness, do anything that you can think of to provoke a change in resistance in the run. Pay particular attention to the connector/wire attach area.
Check the code plug in the fuse/relay box for proper engagement and integrety, including corrosion. This plug is nothing more than a set of jumpers connecting various pins and can have a profound effect on the engine behavior.
Some time ago, I inquired on a plug allowing the use of low grade fuel. The dealer replied, " Here is one you can have. I ordered it for another customer. the bike ran so bad, that he returned it".
I've done this same routine on aircraft. Five experts could tackle a problem with no resolution and suddenly " Bam" there it is!!
Your right, phantom problems are a bear.
Good luck,
M J Stone
Sarge is on the right track, I'll expand a bit on his advice. Twenty years as an aircraft mechanic/electrician makes this scenario very familiar. I'd bet a free lunch that you have a wiring harness or connector problem. Disconnect every connector in the fuel system and inspect it carefully with a magnifying glass. Check for corrosion, bent pins, and deformed sockets. Corrosion can be in the form of a translucent film or slight graying of the components. Spray down with a dedicated connector cleaning chemical. LPS makes a contact cleaning product. A slightly bent pin will distort and enlarge the mating female socket. As a result the socket will not have the proper surface contact area or surface pressure. A damaged socket may have happened years ago and caused be a component which was long ago removed. If such a connector is disturbed as in unplugging and reinserting it will work for a while until corrosion again sets in or vibration causes the contact surface pressure to drop to the point that resistance goes up.
If this turns up no smoking gun move on to the next step. This becomes a bit more difficult, check each individual wire run for continuity at the corresponding connector end. rig up an ohm meter. Tug on the wire at the connector, bend the harness, do anything that you can think of to provoke a change in resistance in the run. Pay particular attention to the connector/wire attach area.
Check the code plug in the fuse/relay box for proper engagement and integrety, including corrosion. This plug is nothing more than a set of jumpers connecting various pins and can have a profound effect on the engine behavior.
Some time ago, I inquired on a plug allowing the use of low grade fuel. The dealer replied, " Here is one you can have. I ordered it for another customer. the bike ran so bad, that he returned it".
I've done this same routine on aircraft. Five experts could tackle a problem with no resolution and suddenly " Bam" there it is!!
Your right, phantom problems are a bear.
Good luck,
M J Stone
Swapped out the Hall sensor, sure seems to run great now....it'll zing me right up to 120+ right quick. Surging gone, idles fine at 1000/1050 RPM(indicated) Only put a few hundred miles on it tonite. I'll really check it out this weekend and see if it lasts. Your connector suggestions sound logical. I've got 30+ years as a maint. electrician in a power plant. I've pulled my hair out too many times over stuff just like this....oh well....thanks, Rex
