Ducati Monster Forum

Moto Board => Tech => Topic started by: He Man on July 07, 2015, 06:33:31 AM

Title: Sudden Power Loss Issue
Post by: He Man on July 07, 2015, 06:33:31 AM
Same bike :(

Bike rides like a slipping clutch at random RPMs, if im hard on the gas or rolling on gently. The motor is actually cutting out intermittently and then regaining, so it sounds like i randomly shut the motor off while riding and then it just continues to rev.

The problem began with the last fill up of gas, about 10 miles in. I also recently swapped to a 14T up front, but I don't see how thats related as I've checked the chain, eccentric and all related bolts. It occurs frequent enough to say that i have atleast 10 instances of the motor wanting to cut out every minute ( i rode it for 20 minutes this way)

I'm not sure if its just a bad batch of gas or my fuel pump that is ready to go. What are some of the symptoms I would see if its the later?

here are the symptoms/other information

-Random and intermittent cutting out of motor at an and all RPMs. Consistently cutting out about 10x a minute.
-Bike WILL run just fine at higher RPMs most of the time
-Bike will stall sometimes at idle when it bogs down
-Did not recognize any increase in fuel consumption over the last 10 tanks.
-Bike runs 93 exclusively


Some Maintenance Items
-Bike is currently at 38k
-Motor is at ~4k miles with the 600 done to include valve adjustments
-Fuel Filter replaced with OEM filter at 28k
-ECU flashed and remapped when the motor was first installed (bike was at 34k) (o2 Sensor disabled)
Title: Re: Sudden Power Loss Issue
Post by: Howie on July 07, 2015, 07:10:56 AM
Won't hurt to look at what is in the fuel tank and filter.  Also while in there check the internal hoses.   Since the bike runs well at high speed I'm thinking not the fuel pump though you could do a pressure check.  Pull the spark plugs and check the color too.  TPS might be faulty.  How is the idle?
Title: Re: Sudden Power Loss Issue
Post by: He Man on July 07, 2015, 09:44:06 AM
Idle is consistent with the execption of the random cutoff.  It doesnt really show up at idle.

I removed the plus when i went investigating the battery issue.  Those plus have been in since i installed the motor.  They looked perfect by the book,  but ill check again at problematic rpms.

I guess it would be a good time to check the filter.  I assume if it was clogged then theres something that wont pass through and is tumbling around the inlet or outlet port.

I have no way of checling the tps since i dont have a ducati diagnostic tool of any sort, that i would have to leave up to ecs to checkout.


Title: Re: Sudden Power Loss Issue
Post by: DarkMonster620 on July 07, 2015, 09:57:07 AM
Quote from: He Man on July 07, 2015, 09:44:06 AM
- - -
I have no way of checling the tps since i dont have a ducati diagnostic tool of any sort, that i would have to leave up to ecs to checkout.



try this, http://www.amazon.com/Centurion-S-Motorcycle-Diagnostic-Single-IAW-5AM/dp/B00EIJMB92/ref=sr_1_2?s=automotive&ie=UTF8&qid=1436288044&sr=1-2&keywords=centurion+diagnostic+tool (http://www.amazon.com/Centurion-S-Motorcycle-Diagnostic-Single-IAW-5AM/dp/B00EIJMB92/ref=sr_1_2?s=automotive&ie=UTF8&qid=1436288044&sr=1-2&keywords=centurion+diagnostic+tool)
Title: Re: Sudden Power Loss Issue
Post by: Howie on July 07, 2015, 11:11:40 AM
You should be able to check the TPS  with a multimeter.  In the case of your symptom you are worried about a dropped signal.  There are three wires at the connector, reference (most vehicles use 5 V, not sure about Ducati), signal to the computer and ground.  A wiring diagram would be helpful.  Positive to signal wire, negative to ground, but not PS ground.  As you open the throttle slowly voltage should go from near zero to or close to reference voltage smoothly with no drop outs.  Big pain in the ass compared to a scan tool.  Since you need a scan tool to set TPS you might just want to head to ECS anyway, depending on how poorly your bike runs.
Title: Re: Sudden Power Loss Issue
Post by: He Man on July 07, 2015, 11:29:34 AM
Looks like a good tool.  Itll be only slightly more expensive then ecs once u factor in all the tolls to get there.

I jisy rode the bike across the city now.  Its surging at all rpms high and as low as 2500rpm.  Doesnt seem like a fuel pump issue to me anymore.  Or bad fuel. Bad fuel would cause it to die at idle.
Ill try out the tps check with a volt meter.
Title: Re: Sudden Power Loss Issue
Post by: He Man on July 12, 2015, 02:52:04 PM
I checked the wiring to my TPS sensor and it looks fine. But my DVOM isnt instant and doesnt have the best refresh rate.

On the other hand, while looking at the wiring,  i forgot that many moons ago i had a Rapid Bike installed and part of the installation was to get a readout from the orange wire. The wire's casing had a small piercing in it but the wire looked intact and ok. I cleaned the contacts out and the bike runs much better. theres still some loss of power, but its very sporadic and i've tried riding all across the rev range for minutes at a time in first and second gear, hard on gas, soft on gas etc.

It still happens, but maybe once every 2 minutes.

Im wondering if theres an issue with the connector at this point. Im going to clean the connector some more and take it apart. Maybe its corroded inside like my RR wire was.

Shit that happens when you have an almost 10 year old bike...
Title: Re: Sudden Power Loss Issue
Post by: oldndumb on July 12, 2015, 02:58:28 PM
Quote from: He Man on July 12, 2015, 02:52:04 PM
I checked the wiring to my TPS sensor and it looks fine. But my DVOM isnt instant and doesnt have the best refresh rate.


An old fashioned analog VOM can be easier to use when checking a TPS.
Title: Re: Sudden Power Loss Issue
Post by: Howie on July 12, 2015, 05:23:47 PM
Absolutely correct.  Wish I still had one. 

It doesn't take much resistance to through the reading off.  Replace that piece of wire and check the connector.
Title: Re: Sudden Power Loss Issue
Post by: ducpainter on July 12, 2015, 05:43:37 PM
Quote from: howie on July 12, 2015, 05:23:47 PM
Absolutely correct.  Wish I still had one. 

<snip>
It's all I've ever owned.
Title: Re: Sudden Power Loss Issue
Post by: He Man on July 13, 2015, 06:33:11 AM
Good call guys. I didnt even think about that!

Shows my age! I forgot analog needle VOMs even existed!

I saw a diagram on how these connectors are fitted up, they are designed to be reused arent they? Minus the actual pin that crimps onto the wire.

Not sure if its good or bad, but i originally placed the tap near the connector. It can either make for a nasty repair or easy repair since i can just snip it off and shorten the wire by 1" without having to splice.

Will update when i get this done. Ive also got my car with the tranny hanging out waiting for a clutch swap....and 1000 other things to do.  [shot]
Title: Re: Sudden Power Loss Issue
Post by: koko64 on July 16, 2015, 07:32:49 PM
How did you go with it K?
Bad connection?
Title: Re: Sudden Power Loss Issue
Post by: 2WheelsFTW on July 17, 2015, 08:10:06 AM
Check your coils?
Title: Re: Sudden Power Loss Issue
Post by: jduke on July 24, 2015, 07:51:46 AM
GuzziDiag is free and will do everything the TechoResearch $230 package will do.
Download the IAW version
http://www.von-der-salierburg.de/download/GuzziDiag/ (http://www.von-der-salierburg.de/download/GuzziDiag/)

But I'm with 2Wheels, I would check the coils and wires.
Title: Re: Sudden Power Loss Issue
Post by: He Man on July 27, 2015, 09:50:45 AM
i havent looked at it yet. :(

between having a GF, work, skydiving, and offroad racing. my street riding is almost non existent, so theres little motivation to even work on the duc.


i have the cables for the old ducati diag program, i heard he quit and guzzidiag as jduke mentioned takes its place.

i am afraid of screwing up my map because i have a flashed ECU with a custom map for my setup. If i screw that up, its another $1k to get it redynoed.

will the ECU spit out all the errors for me so i can atleast tackle them one at a time?
Title: Re: Sudden Power Loss Issue
Post by: He Man on August 15, 2015, 09:05:22 PM
Checked the TPS with a multimeter (anolog as advised by howie) the readings came up inconclusive.  I also had a spare OBD cable laying around and decided to try out Guzzdiag. Guzzdiag works tons better than the old ducatidiag ( i had a lot of issues with the ducatidiag).

I checked the TPS again with guzzidiag and the TPS looked like it was picking up everything. checked it with the bike on too in case vibration had anything to do with it.

Then i did a TPS reset and a memory reset on the ECU. Bam. that did the trick!

Test rode the bike and she roared to life WAY better then ever before. Throttle was SUPER crisp. I hardly ride the bike, and i guess the TPS Is on its way out given the life its lived, therefore it needs more frequent resetting. I'm not really sure on that.

Anyway, i only rode the bike for 3 miles, so hopefully it stays this way. Im thinking about replacing the TPS anyway. Any thoughts?
Title: Re: Sudden Power Loss Issue
Post by: Howie on August 15, 2015, 09:15:43 PM
If the TPS is working all is good.  No idea why your bike lost it's settings.  Glad you are good top go!