[Buhgaboo]

Things are getting complicated...but I think I'm a little closer...while the seafoam has showed promise initially..it is far from consistent...wasn't able to hot start at all today...then after a long soak in the sun...the bike would crank but the fuel pump failed to prime... finally something is beginning to fail...no gas was reaching the injectors... I swapped the pumps relay for the ignition relay...pump primed and I'm back to waiting until 186° to start when hot...can't find my spares so I'm going to try and swap in some new ones on order...in the meantime going to trace the 12v source wire and ground connections...the cold tank of fuel yesterday could have cooled the relays enough to fire up when everything else was hot... curious what that high of a concentration had on my valves...will have to peak when the new ones arrive....

So...to recap briefly...fuel pump primes when hot...never noticed it not to...no ignition or weak and failing ignition...I can typically smell unburnt fuel out the exhaust...ignition relay could be weak or failing to completely energize durring startup...fuel pump failed to prime today...but starter worked...need to trace the 12v source which feeds each of the 3 relays and see how much it drops during initial cranking...swapped the ignition relay for the fuel pump relay...pump primed; engine started...it should not have if the relay was completely toast...but it's not under the same load to energize as the ignition relay is during cranking...so...nothing definitive...but the return of waiting until 186° has me wondering if I had not tried swapping one for another before...the relays are used across multiple bikes but need to look at their placement...might be why this is only happening on the 821 or is this going to start popping up with the scramblers? Still no smoking gun...nor solution...bike is running phenomenal...just don't turn it off...getting closer

 

[Buhgaboo]

Found my spare relays...nope.... damnit

Nothing changed.... wouldn't start a second time...just as before...thinking the 186 is a function of time...not temp...the more often I try and fail the longer the wait is... ignition happens just not sustained... as the rpm stabilizes everything things to work better as if the whole struggle is electrical....but freshly charged doesn't seem to make a lick of difference...going to take some more digging...arghhh

 

[Buhgaboo]

Rule out chassis ground...cleaned and sanded

Rule out voltage regulator...thought the seeping oil might be having a negative effect and while I haven't yet stopped the core issue I did spray the connection with enough brake cleaner to say it's void of any oil...further note the second engine has the same affliction of oil seeping

 

[Buhgaboo]

Well boys and girls SHE STARTS RIGHT UP...EVERYTIME!!!!...I believe I have it isolated... disconnected the MAP switch and she fires...

Not clear if the switch itself is bad or some interference in the wiring...I had two...bought a third on eBay...all failed to solve the issue...going to try one more from new...will report whenever that part gets here...in the meantime

updated part#55244331A

I never realized there are two air temp sensors so I disconnected the airbox temp and ran that outside...still no start... disconnected the map sensor under the airbox...vroom vroom..
Plugged it back in...no start... disconnect again...start...plug in again...wait 30 sec...start...wait 15...start....wait 5...start... immediately...no start...now I have to wait...and wait...it's either sticking...or sending a fouled signal...and being retained...map sensor plugged in...I started it...killed it....but left key on...waited 5 min....she cranked and fired up but I could clearly tell a difference...it was slow as if the battery voltage was low...she did fire up...but only barely...would not start again without a long wait...same scenario with the sensor unplugged...she fires up everytime...no waiting...like the battery is at full charge...so...

the signal was good on startup...fires right up...gets sent an incorrect reading from the MAP sensor...fails to start a second time...compounded by an incorrect fuel mix; it becomes increasingly difficult to start...now I'm fighting an incorrect reading and flooded with a still incorrect mix.... disconnect it and all my problems fade away.........minus the glowing CEL

Reading up on relays...Its possible my rapid firing the ignition switch and constant off on of the key was sending an inrush of current repeatedly to the relay(s)...this sort of thing can kill it...and seeing how the fuel pump is a grand...I'ma going to stop that practice...and might explain why it failed to prime...it happened one more time parked in a cool garage with a different relay so I'm not 100% sure...that will be a separate post if it fails...heed the warning

 

[Buhgaboo]

Plot thickens...hooked up a voltmeter using some jumper wires to the MAP sensor...signal is good...starts on demand...no drama...reads 5v reference and 4.7v signal....fire it up...bounces around the 2.85v....turn it off...4.7....fire it up...2.85v...off...4.7...she fires every time...no CEL...as soon as the bike turns off it's reading 4.7...no signal is being retained...wait... wasn't that the problem part?! scratch off the MAP sensor...maybe

Removing any of the three wires in the clip trips the check engine light straight away...but something is/was definitely getting buggered...she's working like it never was an issue now

Removing any of the three wires trips the CEL so it's not a complete failure....and the loss of the ground only opens the signal to 5v... essentially full gas...it stinks like a 60s muscle car....but a weak signal voltage or reference voltage goes the other way...hard to start...

With the jumper wires in place I was starting it at will...I fire it up ..turn it off...fire it again...she seems to be working...do it again but less down time...by the third off/on sequence she coughed like it was flooded and had to wait...not long...but too long...brought it up to temp this time... turned it off... try to restart...one try with the kill switch...nope...quickly try key off and on...vroom vroom...holy shit 194°....but I'm not feeling victory...few more tries...feel like I flooded it again with the attempts...wait...20 seconds or so...nope ...few more tries nope....temp drops to 186...nope... quickly pulled the MAP sensor plug off...temp 180....nope...she smells like fuel...a lot of fuel...I know it's going to be a wait...it's getting late...beer me

Think disconnecting the MAP sensor only put the fuel map to default... growing increasingly doubtful it's bad... but something is throwing the mix off...and when she tries to fire and nearly does...a key on off scenario tends to work...the MAP goes to reference voltage with the kill switch...turning the key on and off has no effect... at least not at the sensor level...a bad signal might be still maintained in the ECUs memory? Air temp I feel is good...as is the water temp...I can see the value on the dash...will take a closer look at the lambdas....

 

[Buhgaboo]

Finally!!!!! OMG it's over...lol...she purrs like a kitten....barks like a monster again...hot or cold!!! Hot damn...lol

TLDR: rear lambda sensor was faulty...wires loose in the MAP sensor connector...and more loose wires...probably a mess of other locations


SOLUTION AND TEST:

So just to summarize...if you can't start your M821 hot...pull the rear lambda sensor...there's 4 wires...put a multimeter into the black and grey wires and get it up to 600° voltage should read near 1v....yes it makes its own voltage when hot...crazy stuff...now remove the heat...it should drop to near zero pretty quick...if it doesn't... keep heating it...the other two wires are for a heating element that would normally speed up this process...she needs to be painfully hot to work...if you never get 1v...or get negative numbers when the heat is removed she's toast...mine appeared ok at first...but the longer I heated it the lower the voltage got...

My assumption on the problem...it tested ok or near enough...that is until it got to temp...then it was returning negative voltage and maxed out at .5-.6v...it appears I have been waiting for the sensor to cool down to under 600°...that way it just sends back nothing...0v...and by the time things are brought in check...the engines already running...albeit richer than it should...and the failure seems progressive but gradual...never triggered a CEL.....I've got a 2 minute video so you can see for yourself if your interested on testing it

Now Im confident the rear cylinder lambda sensor was the root cause...it's something that can be tested and replaced pretty easily....but...some other anomalies kept popping up worthy of note...fuel pump failing to prime...exhaust flapper didn't cycle...it felt like the battery was dead on cranking...my headlight turns off if I move the bars to the stop....rear brake doesn't make the stop light work...clutch switch isn't working...turn signal is on occasion intermittent....I've come to expect these gremlins everytime i remove a connector and in the past have sorted themselves on they're own...until it hits something important....if these sound familiar...your going to want invest in something to remove wires from there clips to restore the lost tension in the contacts

...in all likely hood I swapped in another bad or not as bad lambda sensor from my spares long ago and assumed it was fine, fixed, or tolerated...never tested it...it failed it's test now though and the bike is an absolute dream just to hear it idle.... however the problem was compounded by a weak wire coming out of the MAP sensor...this was why I couldn't restart when cold...while testing the MAP sensor... voltage would slowly recede to near zero...thought a connection came undone...but my jumper wires were in place...all three wires plugged in the MAP sensor clip had next to no tension...pulled each one out from the clip...pushed the contacts down to make more drag...fired up...but would still not fire up when hot...one cylinder seemed to want to go but it just wouldn't catch and it didn't improve with more attempts....after pulling the lambda sensors i broke out the multimeter to test them...at first they would get hot..climb to near 1v then instead of immediately going to zero as they should they just kinda lingered about slowly drifting to .4v...is that good? I've got three others....turns out there's a heating element that brings them up to temp so after a prolonged period under the torch I was able to get them to jump back down .01v nearly immediately...on two of the four I have on hand...a closer inspection showed that both bad lambda sensors were on the rear cylinder...I can't believe how smooth the motor is now...and it's going to take some time getting use to being able to start it whenever I want...phew...it's done...going through the clips checking they're tension is going to become SOP from now on


VROOM VROOM...off...VROOM VROOM..lol

A bonus for those who made it this far...they're pricey...the temptation will be eBay...if there's corrosion around the nut it's probably coming from the rear cylinder...you don't want that one

 

[Shrek]

Well that was well thought through and well posted

I do hope you do have it sorted.. there were a lot of little things there too..

@Shazaam! .. just in case he lost interest in it earlier

 

[Buhgaboo]

Uhg....still some anomalies to track down...she starts hot...but not nuclear and more often than not needs the key off/on to get ignition to stick...cranking when it's north of 210° feels labored...ignition feels weak...and it doesn't start beyond the third successful startup...not without cycling the key...that part might be the immobilizer timing out? In any case I'm gutting the bike and sorting every electrical connection first...a close look...despite the plastic housing...all use the same type of terminals...should be pretty straight forward.

Lambdas...Ducati in USA wants 300ea overseas 200...found a few other brands use the same sensor for 65... Bosch has a universal version for 65... attaching Ducati doubles the price to 120...not sure what's going on there...

Sensor p# AZD0101 B002 NTK Japan

 

[omgwtfxu]

Yes. Congrats on the solution. Your sanity has been restored lol.


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[Buhgaboo]

Yes. Congrats on the solution. Your sanity has been restored lol.


Sent from my iPhone using Tapatalk

Not so fast...it's as if I've gone backwards...I've made zero progress...if I shut it down immediately...it won't start...but it if it runs a bit...I can continuously restart...upto 170°

Ordered the Bosch lambdas...we'll see if they work or not

Currently...I can start stop start all the way to 170° ....after that it feels like the battery doesn't have the juice.. possible I killed it with the constant stopping starting every few degrees...but on a separate occasion... could only make it to 170° it's a bit strange...this is after I swapped starter solenoids and cleaned some terminals along the starting circuit...I'm going to swap back the old solenoid and recheck the lambdas...I've largely ignored any ECU connector...but I'm backing myself into them...

Since cleaning a bunch of terminals...I've seen some increase in crank strength at temp...it's sporadic from week to almost...can't rule out a bad fuel plan from a sensor....can't rule out the battery... can't rule out a bad connection...unplugging sensors when cold will get the bike running...but you won't be able to start it at temp...it appears as if the mix is right but fizzles from lack of voltage....it also feels like everything is right but just dies after 1-2 revolutions...but this isn't consistent...sometimes it feels the power is there...other times not....disconnected the map sensor...won't start hot.... disconnected lambdas...tried restarting it at 150°....nope...the lambdas should be good...I recall one testing good and the other read -.01v...i stopped early... it might be worse...I need to retest them...

I found quite a bit of connectors with some oxide buildup...cleaning any of them hasn't yeilded any miraculous improvement...yet...with the exception that I rarely have to cycle the key to get it to start and when I do...it makes no difference...if it didn't start it still won't..checking the resistance from ground at the battery to chasis ground is nearly zero...will check the resistance at the ground for each important module next round

I haven't tried starting every few degrees as I did this time...my last victory lap had me starting up at 196°...3x...in a row....now, it ceased to start beyond 170° and it felt labored and weak when any ignition happened...put 60 miles on it...let engine temp go up to 200°...she cranked...pretty solid...fired...but just wouldn't keep going beyond the 1-2 revolutions... similar to how it was...and any attempt was just as disappointing...with the exception that it's almost firing...before I would smell unburnt fuel like it was flooded or a bad combustion...now it's igniting...or almost igniting...just not sustained

 

[Beauwulf58]

I think it goes back to the Euro 4 exhaust spec. They compromise to make the standard for sure. I would throw a Power Commander on it with a good base map and I'll bet it goes away. If you get a PC, be sure to disconnect the battery for 10 mins to reset the ECU to defaults. There's a chance it could be a clogged catalitic converter if you still have one on it... just a thought.

 

[Buhgaboo]

Good news bad news....still won't hot start...as soon as it crosses 170° it no longers sustains ignition....

It's not the lambdas... probably...the ones I ordered had a 18mm thread...need 12mm 1.25 pitch so I'm sending them back...In the meantime I placed a 330ohm resistor on the heating element and a 1M ohm on sensor...this in effect bypassed the lambdas and no CEL...near same behavior on startup and exact same failure after 170°

Going to install the new MAP sensor next time

 

[Beauwulf58]

Have you tried these guys?

Customer Service Ducati

This section is entirely dedicated to your needs and any kind of query you may have about Ducati. To make it easier for you to find your way around, we have created a list of the most frequently asked questions, divided into subject areas, along with their answers.

www.ducati.com

 

[Beauwulf58]

I have three possible things to check.. Fuel line hydrolock (insulate lines), and ignition pickup coil gap (check and set as required). Could also be the pickup coil breaking down with heat (check for signal when hot) That's about all I can think of....

 

[Buhgaboo]

Could this finally be the solution?!..the temps are in the high 90s lately and I'm getting the familiar sit and wait phenomenon but now it's right from the get-go....whatever the problem is; it's nearing the end of its life...fingers crossed... should be hearing from me soon enough one way or the other

One-way starter clutch 70140411a 2015-16 m821

Seems to be a new part number every year...could just be coincidence or they still don't know how to fix it... curious

Sent from my Pixel 4 XL using Tapatalk

 

[Buhgaboo]

Hmm....the parts are indeed worn...there's a buildup of crud on the flange as well as significant pitting on the clutch surface...the crud crumbles like graphite...the one-way clutch pieces have flat spots as well...testing the mechanism proved pointless, only human level of torque on a well oiled bit of metal...it didn't slip...but further investigation led to a boundary layer of buildup... curious if a cleaning alone would have accomplished anything...Its possible I'm going to be in here again, I only bought the one way bearing...I scored the flange with 1000 grit...only trying to ease the pitting... I still feel grooves...going to go at it a bit more watching FP4...I'd just replace it but I'd rather try this out for science...lol

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[Buhgaboo]

Wasn't it either.... damnit...maybe it needs some miles...maybe it needs a new flange...cranking doesn't seem as labored... it just doesn't start...cranks...and cranks...and cranks... nothing