Non-Smooth running problem

[blakduc1]

I own two identical 1992 anthracite 907ie's. I have had the following problem with each of them:

The bike sometimes runs pretty smoothly when tooling around easily; other times it tends to jerk and cough and sputter a little-- to not be smooth. But in hard acceleration and running on up through the gears, then running hard, it does fine. The problem seems to get worse as outside air temperature increases. In cool weather it is not as noticeable. I have open pipes and either Euro chip or FIM chip.
With this problem, the bike is difficult to ride through town but easy to ride on open twisty roads. VArious mechanics have not been able to solve this problem. One changed fuel pressure once and it helped some, but not completely. The dealer in Atlanta has never been able to tell me why it cannot run smoothly all the time.

Has anyone experienced this problem? Does anyone know the solution? It is hard for me to believe that a bike that can run so good and so strongly cannot run that way all time at various speeds...

thanks,
dp

[cagiva905]

First of all check all connectors to the sensors, corrosion causes faulty readings for the ECM. You also miht want to check synchronisation of the 2 cylinders, both on midrange and idle.

Second you might want to check the air temp sensor in the airbox. If it is defect, the mixture gets leaner thus making the bike run not as good. Sensors like this don't always break down completely, sometimes due to ageing their values seem to shift a bit.

You can find datasheets for all sensors on
http://www.endless-horizons.net/efi/efi.htm
Website is for Cagiva Elefant, but sensors are all identical.

Michiel

[du907]

I checked my throttle position sensor for the factory spec values. I then ballanced the throttle bodies. I then took the bike to a friend with one of those emmission testers that the states use on cars. He put the "sniffer" in the tail pipe and I trimed the CO to about 3% with the trimmer on the the ECU. It help mine a great deal. Check the FIM site for more information.
du907

[blakduc1]

Thanks, guys.
This helps some by at least giving me some ideas of what could be wrong. However, I do not really know how to do all that. I guess I will need more specific "how to" info or either find a Duc guy that really knows what he is doing with these "ie" engines. Know anyone in the Atlanta or Athens GA area??? How do you "check" the air sensor???
Should I just replace it? Did y'all have a similar problem and were able to correct it?
Thanks for your responses.
dp

[cagiva905]

All you need is a hair dryer :screwy: , an accurate thermometer and a multimeter.

Take the sensor out of the air box, measure ambient temp, and measure the resistance of the sensor.
Now heat the sensor with the dryer, measure temp and resistance again.
You could do this with several temperatures.

You can now compair the values with those on the datasheet (see EFI website).

Same goes for water temp sensor, just use warm tap water...

Michiel

[Rasser]

Hi All,
Not looking in here too often, but just read this thread. Have you sorted the bikes?
Mine is -92 Black Euro. FIM chip (tried also with the std) Staintune and stock filter.
I have on and off had a similar problem. First time the Summer after I got it in 1998 and latest from September this year. Brought it on a trip to Italy in my van (was there for work) and enjoyed a brilliant day from Rome to Terminillo mountain and back. Later same week after 100km it started for the first time in about two years and it has been there since about 50% of the riding time.
As you say it will pull clean from bottom if throttle is applied fully, no hickups. It will also go 200km/h w/o halting, but as soon as you enter normal driving speeds it will kill-out, splutter and be very rough on the drivetrain unless it is pulling/under load so in slow traffic or at the traffic light I have to ease it with the clutch to get it going.
When at standstill I turn it to i.e. 3000rpm and lock the throttle, it will halt, splutter and go down to 2000 and up to 4000 sounding like it will die in a second, but it will actually just stay like that. When I release the handle it will idle nice and stable at around 1200rpm.
I am into auto-electrics, just do not have access to the testers which might be able to identify the source of this. Also, the Ducati dealers here in Denmark will not have testers to fit the older bikes.
It could be both electrical or fuel. Fuel lines, the TPS, ign-cables, and frequent fuel filter, plug and filter changes.
I will just mention that it had an engine rebuild last Winter so valves, seats should be ok. Also it was adjusted in June, TPS, balance, CO etc.
And I am not talking about the normal 907 and other Ducati nicks at low revs/speed, these are familiar and ok to live with.
ANY ideas are most welcome. I did measure all the sensors using the very helpful information from the data sheets, but heard lately that you cannot always trust only the mV readings unless tested over a range. So if you have some experience with locating this ..
Otherwise I have to start changing one part after the other - and that will get expencive. Much better using it riding the bike.
Thanks
Per

[cagiva905]

Apart from the sensors that I mentioned earlier, only one or 2 sources come to mind:

check the TPS, if the problem does not occur under full throttle, you might be in an area of the potmeter that has no wear, and under normal driving conditions the potmeter is in an area where it is used most, hence more wear of the resistor surface.

Also check the ignition boxes and their connectors. I've had a similar problem once and it turned out to be corrosion in the connector. Cleaned it, applied a very small amount of copeer grease, no problem since (over 8 years of heavy duty mileage)

Michiel

[Rasser]

Thanks cagiva905,

I did buy a new TPS 3 yrs ago which didn't solve the problem. The thing is that I can fight with it the remainer of the season, and come April it might not show for some time.

I will check a few more things when I get time next week also the ign.boxes.
From autoelectric I am always very careful about contact points, ground connections. Have installed relays for the headlamp and to releave the ignition switch. I also changed the relays for the fuel pump as they melted at the contact points. I first used std. relays, but if you have to for emergency/getting home remove from the holder when not in use as they will stay switched on and drain your battery.

I have also tried to add injector cleaner and from advise also added "carburator alcohol" to get water out of the system - if any.

Will keep you posted and do let me know about any input you might have.
OaO,
Per

[hondaboldor]

Hi Guys,

Have observed these "3000 rpm hiccup" posts for a while now, and I have the same problems for a couple of months now. Just kicked in all of a sudden.
Symptoms with my bike are: misfires and hickups between 2500 and 4000 rpm when engine is hot. One moment I'm traveling 80 km/h with no problem and a couple of minutes later the bike is stuttering and becomes near undrivable. Full throttle is no problem, and top speed is aprox. 220 km/h....
I don't believe that anyone has already been able to pinpoint the exact location of the problem and neither have I (yet.... I hope).

At this point all I can do is tell you guys what shape my bike is in and what I've investigated / done to this point.......
My 907 is stock with the euro chip. Only exception is the exhaust (of course )
First thing I replaced where the spark plugs (changed from NGK to Champion) without result.
Next I have checked the injection system; followed the FIM => set the TPS to 150 mV at fully closed butterflies. Replaced the fuel filter. Measured the injection pressure => somewhat over 3 bar, so no problems there.
and finally balanced the butterflies. Measured the air-temp sensor and the water-temp sensor => both in spec ( aprox 3,5 - 4 kOhm at 20 deg C as I recall)
Still the thing had hickups.

At this moment the bike is (almost) completely disassembled. Checked the valves => only my vertical exhaust openers were out of spec ( 0.05 - 0.10mm => adjusted to 0.15mm.)
Checked the TPS with running engine with an osciloscope ( sort of graphical Voltmeter) and the signal was clean and without rimples or 'noise'. (this thing is not lineair indeed)
Heated up the TPS => no change in measurement. conclusion; TPS ok.
Read out the computer for stored errors => no errors there.
Took out the injectors and cleaned them with compressed air. (the little filters had rust in them!!!!) injectors are clean now.
Cleaned every electrical connector in the system.
I am building the bike together now and hope to test it next weekend.

When the problem isn't solved by then, I'm taking the bike to a Ducati specialist here in Holland (Star-twin) where the bike will be put on a Dyno. (already phoned them about the problem)

I'm keeping you guys informed about things.

regards,
Sebastiaan

[Rasser]

Hi Again from Denmark.
Good description Sebastiaan. Exactly my experience.

The other day, even I almost had given up and parked it for the Winter, I disassembled the fairing bits, again, again and went through the following:

Cleaned EVERY connector, fuse, pins on relays, etc. Not much to see, but a black spot on one fuse.

Replaced the ø4 hose that runs between the injector bodies and the pressure regulator (do not know why - just did).

Changed the plugs with new NGKs.

Changed the ignition cables (which I think is the culprit, why ....).

Measured the pressure, but no changes to filters, TPS or CO at this point.

One very minor thing was that I removed one 0,1mm spacer under the front pick-up (why, ehhhhhh!)

I did not do runs between the various tasks as it was very close to zero degrees, pitch black outside and patches of ice. When that cleared last Friday I drove the bike home and have since done 150 kms and have not seen the problem again.
Have had this problem very bad for the last four-five weeks about 80% of the time ridden.

I was so close to get new ignition coils and pick-up's, but the price from the dealer was Eur 160 plus 25% VAT, yes we pay 25% VAT on everything, I thought it worth to try the things mentioned above.

SO, I think it was my 5 year old NGK racing ignition cables that caused it - and then maybe not. Might try it out when Spring returns.

Good luck sorting your bikes.
Per

[persempre907]

I was so close to get new ignition coils and pick-up's, but the price from the dealer was Eur 160 plus 25% VAT, yes we pay 25% VAT on everything, I thought it worth to try the things mentioned above.

Hi Per,
If you want to replace the pickups (and the coils also I think) you can try to an automotive dealer. In fact, those parts were mounted on many Fiat/Lancia/Alfa Romeo cars.
So, if you take apart and bring them to the dealer I'm sure you will find them at very cheaper price.
Ciao

[Finnpaso]

Btw, my workfriend had to change pick up to his Elephant 900 GT and when he got new from Italy, it had newer style connector with different wiring (remembering, that new had 3 wires...). They sayed, that cant find anymore that older pick up !!!! I think, 900 GT have just same pick ups, as Ducati 907IE... at least seems just same!