907ie misfire - maybe a cure???

discussions specific to the 907IE
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Ducman
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Joined: Tue Jul 25, 2006 12:00 am
model: 907 I.E.
year: 1992
Location: canada

Post by Ducman »

Found this:
Setting the Throttle Potentiometer
This is an extract from a service bulletin issued by the factory in Oct 1992.

Model 907 & Cagiva Elefant 900 IE & GT models

remove the filterbox cover and the air filter; unscrew the anti-sticking screws i) and starter adjust ii). Screw up to the moment that the throttle is totally closed. Check this position by touching the filter side and having the throttle operated many times. (open the throttle a little and snap it closed ounce or twice)

Connect a digital voltmeter (accuracy=1mV) to the pin no 11 (-) and no 17 (+) of the central box terminal board iii) Then check that the voltage reading (switchboard On) to be 150 mV ± 15mV. Otherwise loosen the potentiometer iv) fastening screws setting their angular position up the the mentioned voltage figures are got. During this operation horizontal cylinder throttle must be forced to stay closed. (be careful what they say about being forced, what they actually mean is do not allow the turning of the potentiometer to open the throttle body butterflies)

Using the anti-sticking screw i) of the vertical cylinder (master) adjust the throttle opening up to a voltage reading of 300mV ± 15mV. In the same way adjust the anti-sticking screw of the horizontal cylinder up to the contact with its support, or when the voltage figure previously stated starts to increase. At this point the air flow rate of the throttle at idle rpm ratio is in condition to allow a positive and negative adjustment (rpm increase or decrease) using the by-pass screws.

Adjust the by-pass screws at one opening turn and after the usual preparation, arrange engine starting; under these conditions (20°C approximately for air, & oil temp.) rpm range must be stabilised at 900-1300 rpm approx. On the contrary, ( if this is inconsistent) check again with anti locking screws loosened, that throttles are resting on the duct indeed. (throttle body butterflies properly closed)
Go on with the usual procedure of adjustment (see our service bulletin No. 149 dated 20/06/90) specially paying attention to the mixture strength balance of the two cylinders (CO equal figure 3-6%) As a final practical test, alternatively disconnect the two ignition spark plugs, noting (using and auxiliary digital rev counter) that the engine rpm ratio decrease is repeated at the same figure.
Adjust the start opening screw ii) in a way to get an rpm rate of 3000± 500 n/1 with hot engine and starter totally turned on.
Notes for the above.

Anti-Sticking screws = throttle body butterfly stop screw
Starter Adjust screw = warm-up lever or choke
Central Box Terminal Board = ECU
potentiometer = in this case the throttle position potentiometer
The standard running configuration for these tests is to make sure that you have adequate ventilation for the exhaust. If you run the engine for extended periods you must have a cooling blower and the engine will have to be run using a remote fuel tank that holds just a small amount of fuel, remembering that the remote fuel tank must have a free flow return pipe as well as the normal fuel feed. The fuel injection system has a bypass that must be fed back to the tank. as an example I have a small lawnmower fuel tank with a fuel tap for feed and a return pipe welded into the top air space for the fuel return
Laddie
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Joined: Fri Sep 21, 2007 12:00 am
model: 907 I.E.
year: 1991
Location: Australia

Post by Laddie »

these instructions are exactly what I have used to set the TPS previously - I have also "played" with the zero position (throttles shut 150 mV +/- 5mV) to make the mix richer / leaner...

they are good instructions and this will result in the engine having the perfect idle...and (in theory) good balance / mixture throughout all throttle settings.

BUT what do you do when the manifold vacuum is balanced at idle but different by 10% or more for each cylinder at 4,000 RPM??? This is where the bike spends most of it's time - running, not idling...

in my case i have had to adjust the butterflies from both set "fully shut" to about 1/2 a turn out-of-synch to get the cylinders balanced at 4,000 RPM (unloaded) which is probably about 3,500 RPM under load.
then turn the idle adjust screw to 300 mV / 1,200 RPM...
the idle manifold vacuum balance was then achieved with the air bleed (by-pass) screws.
I know there is a second idle stop screw in there - I just can't set it with the air box in place...so I just use the one closest the TPS.

I'm not going to throw the $$$$ at flow benching the throttle bodies - I can't afford that and don't require that level of performance...might be a different story if I was racing...

do you have a copy of the service bulletin referred to?
Laddie
907ie - for fun and frustration
900SS - for when the 907 won't go
XS1100 Yamaha - previous tourer
TZ253/350 A/B/E Yam - previous boy racer (DNF)
CB750K7
CB500Four
CB250
CB175
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Tamburinifan
paso grand pooh-bah
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Post by Tamburinifan »

Nice post, Ducman, thx!

Got a textfile of the E 023 chip today. There really is a lot of preignition everywhere.
F e 11% throttle, sort of cruise mode: 20 degrees at 1500 RPM, 25/ 1998 RPM, 35/3000, 48/3997.
Max adv WOT 42/ from 5k-9k.
Breaking points f fuel & ignition not always the same as well.
Lots more pre ign than I`ve seen on other maps but what do I know, ie rookie as I am.
Gert

907 I.E. -91
M900 -97
MTS 1100s -07
blakduc1

The Common ? 907 hiccup problem

Post by blakduc1 »

Seems this is a common problem with 907s. See my post from July of 2006 "Non-Smooth running problem" and others like "3000 rpm Hiccup" . SOMEONE must have accurately diagnosed this problem and cured it. I may try to contact LT Snyder and ask him about it; see if he has worked on this or cured it in the past. Will post his response.

Anyway, let's hope Laddie's cigarette butt is the cure because it will be the cheapest no doubt.
dp
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persempre907
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Post by persempre907 »

I also had such problem and I also started a similar thread some time ago.
Now I have fitted open exhaust on the bike and the misfires appear only at 2.000 RPM.
Ciao
Francesco
Ducati 907IE 1992 Rosso
Ducati 907IE 1993 Nero
Moto Guzzi Galletto 1960 Sabbia
BMW R Nine t 2019
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Ducman
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Post by Ducman »

this guy seems to have it figured out
http://www.moto-one.com.au/performance/ ... ction.html
Laddie
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Joined: Fri Sep 21, 2007 12:00 am
model: 907 I.E.
year: 1991
Location: Australia

Post by Laddie »

Ducman - you're one step behind me...lol
I emailed Brad at moto one yesterday...and sent a link to this forum.

My questions are:
how much does the MAP sensor output affect the ECU outputs - compared to the TPS?
and
could the ECU get upset by a wide-tolerance signal from a sensor [caused by instantaneous vacuum fluctuations]?

Brad indicates he owned an 851 [which has the same injection system as the 907ie].
what I did note is that his 851 air box was run with the top off - which would have some effect on the vacuum the MAP sensor sees.

he seems to know what he's talking about and has all the good gizmos to test results - hopefully he will respond.
Laddie
907ie - for fun and frustration
900SS - for when the 907 won't go
XS1100 Yamaha - previous tourer
TZ253/350 A/B/E Yam - previous boy racer (DNF)
CB750K7
CB500Four
CB250
CB175
DT175 Yam
PE250 Suzuki
blakduc1

Post by blakduc1 »

Great information from that link, DucMan.

Man, this sounds like a real key to finding a solution to this problem --- the mapping possibly needs to be fine-tuned. Imagine that. So why did I buy an expensive FIM chip for the 907 that still leaves it stumbling and coughing??? I thought they were supposed to design mapping that got the engines to run and respond better than stock, wih open pipes, etc. I have the USA chip along with both Euro and FIM versions. And CObra F1 pipes and Termignoni carbon fiber pipes. Bike still stumbles.......

As a side note, I posted LT Snyder at DesmoTimes and asked about this problem. He said the 907 was one of the only bikes he had run up on that he could not completely sort out. He thought it was maybe the P7 ECU that is the problem. But evidently the 851 and some 888s also used that unit? Didn't those bikes run good? They raced , yes, but were also on the street. And are 4-valvoles also.

Please post any updates you guys have concerning what you find out. Thanks.
Tamburinifan
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Post by Tamburinifan »

100 km`s today and I must say the stumble has gone from unbearable to acceptable w the ciggie butt. :thumbup:

More ign examples, 907 compared w the Grand canyon on Brad`s site:
F e at 2000 RPM, 10-12 % throttle: 8-9 degrees preignition on GC, 20 on 907!
2,8k/16 GC, 2,5k/30 907, almost full normal advance for a 2V 900!
Have 2k/14 on my carbed Monsters programmable ignition.

No ie expert but what do you think?
Gert

907 I.E. -91
M900 -97
MTS 1100s -07
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Finnpaso
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Post by Finnpaso »

blakduc1 wrote:So why did I buy an expensive FIM chip for the 907 that still leaves it stumbling and coughing??? I thought they were supposed to design mapping that got the engines to run and respond better than stock, wih open pipes, etc. I have the USA chip along with both Euro and FIM versions. And CObra F1 pipes and Termignoni carbon fiber pipes. Bike still stumbles.......
:confused: I have tuned 907IE engine and i use P7 with AMB and tuned(with FIM software/laptop) FIM chip with 7.4% rised fuel ratio in hole range and function VERY WELL in hole rpm area, running very smoothly hole area... I think, If have such problems, then fault must be in injection/throttle bodies adjustments/fuel system or electrics(like in ECU, or sensors), NOT in FIM chip!!! If You find some spare P7 ECU to test, then You can log out that ECU problem. :thumbup:
Antti http://www.youtube.com/watch?v=HeKOh3XoXPg&NR=1
KTM 990 Adventure -08 metal dark grey
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Tamburinifan
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Post by Tamburinifan »

I have tuned 907IE engine and i use P7 with AMB and tuned(with FIM software/laptop) FIM chip with 7.4% rised fuel ratio in hole range and function VERY WELL in hole rpm area, running very smoothly hole area
Did you alter the ignition map?
Gert

907 I.E. -91
M900 -97
MTS 1100s -07
Laddie
Posts: 56
Joined: Fri Sep 21, 2007 12:00 am
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year: 1991
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Post by Laddie »

it's unlikely to be the FIM / Ultimap chip where the fault lies...
the fault is there with the OEM Ducati chip, too...

the problem is too common to be simply component related.
if you assess the fuel injection components, they fall into two categories:
1. they either work or they don't
2. thay can partially fail but are easily diagnosed
I have swapped too many parts out to test that myself...and the components are reasonably reliable. the ECU has a limp mode so that should isolate and signal inconsistancy - except if the component signal is erratic.

I do find the idea that a chip has a 7%+ increase to fuel across the whole map is a bit of a cop-out though - unless there is an equivalent return of HP throughout the range (or that it is designed to be run at leaner settings..just phase-shifting the map - but I can't see why you'd do this...

of course running a richer mix will improve just about everything - except consumption...although with the cost of running a 907 the cost of fuel per kilometer pales into insignificance with the cost of maintenance...

I'd be interested how much CO these bikes are outputting...
Laddie
907ie - for fun and frustration
900SS - for when the 907 won't go
XS1100 Yamaha - previous tourer
TZ253/350 A/B/E Yam - previous boy racer (DNF)
CB750K7
CB500Four
CB250
CB175
DT175 Yam
PE250 Suzuki
Frenchconnect

Post by Frenchconnect »

I am very glad that i finally hear that i am not the only one with this problem!!!
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Finnpaso
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Post by Finnpaso »

Tamburinifan wrote: Did you alter the ignition map?
No anykind of need, cause it function very well now... :thumbup:
Antti http://www.youtube.com/watch?v=HeKOh3XoXPg&NR=1
KTM 990 Adventure -08 metal dark grey
Paso 750 -89 red/metal grey
907IE -91 red/metal grey
907IE -91 red
2xST4S -02 red/metal grey
ST2 -01 red/metal grey
Volvo V70 Bi-Fuel Classic/titanium
blakduc1

Post by blakduc1 »

Quote: "it's unlikely to be the FIM / Ultimap chip where the fault lies...
the fault is there with the OEM Ducati chip, too... "

Yes... but my point was just that if the problem exists in the Ducati fuel mapping, then I would think that the FIM chip would have solved that problem by designing the best map for that engine..... that they would have been aware of this stumble and remedied it with their product.....
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