907ie misfire - maybe a cure???

[blakduc1]

Finnpaso, you say you "tuned" your engine with FIM software ... does that mean you programmed your own chip to get it to run right? Or just installed one with increased fuel through whole range?? I am not sure exactly what you did..

..and did you have the hiccup problem before you tuned it?

[Laddie]

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.....

I'm a late-commer to the 907 fraternity. I haven't owned my 907 since new - so I don't know if the stutter / misfire was there all along. I find it difficult to believe that Ducati (or any OEM) would or could sell a bike that ran that bady... although the local Ducati agent rode the bike once and said something to me to the effect " you can't expect a Ducati to run smoothly - it's not Japanese"....maybe so but surely it was designed to run better than that.
Was the misfire there in "as new" machines - or does it develop?
If it was there from new (15 years ago) I would have thought that it would be very hard to sell the bike - a decent test ride and you'd pass it by...
If it gradually develops that would indicate tolerancing problems - as components wear a bit the various tolerances send it out-of-tune...most commonly engines can be tuned back (that's what mechanics do) so I'm kind of bewildered...
Maybe in the quest for engine response the fly wheel is engineered too light, too. I don't suggest that would cause the problem but it might compound it...

back to the chips - I'm sure that Ducati, FIM and others design them for performance - and the testing is mainly done on dyno. I expect that the tests are fairly short and not too much "on road" is done by the chippie - and that when it is on road tested the bike is cained hard - not cruised or trickling through traffic...
I am aware some chips just rich-up the map with fuel to try to eliminate rough running - maybe that's all that can be done with the dinosaur P7 injection system.

again, I don't know - but I'm sure there is a lotta science in developing the fuel map. It must be right most of the time.

If i'm going to add fuel anywhere I'd like to see some HP / torque improvement. If I had the time and money I'd probably consider fitting a Jefferies MyP8 and play with it...but I'm not willing to throw any more $$$$ at the bike unless it's a guaranteed fix silver bullet.

the misfire in mine has been observed on a computor - it took them a few days to see it because it's intermittent...the spark and fuel times go all over the place (that's not the chip doing it - it's the ECU). The only reason the ECU will screw up like this is if the ECU is rooted (highly unlikely) or the inputs are haywire.

the basic "variable" inputs are:
12 V from the battery (steady - so long as the regulator and rectifier are OK)
the TPS resistance / output voltage [two TPS units trialled]
the resistance from the WTS
the resistance from the ATS
the resistances from the MAP sensor
the timing signals from the hall effect sensors (crank and valve gear timing)

we did observe an AC spike from the regulator (on oscilloscope) which we thought might upset the ECU and we put in a new unit - the wiring was also modified a bit to ensure the power supply to the ECU was conditioned through the battery.
we put in fixed resistors to lie to the ECU so the temperatures were set at WTS 80 degrees and ATS 40 degrees...
the hall effect sensors were swapped with proven good ones
the MAP sensor still had fluctuating outputs...
the power supply to the MAP was even rigged up with batteries to produce a steady 5 volts supply...the output resistance was still fluctuating.
The MAP output was steady with engine off (as you would expect).
We swapped the MAP sensor with a proven operational one.

in this whole exercise we did not remove the vacuum from the engine (that I remember, anyway). I don't know why - but I'm sure we didnt.


about 6 months later after this testing I tried the cigarette butt.
I am yet to put it on an oscilloscope but my guess is the MAP signal will be "steady" now (within a reasonable operational tolerance).

I'd like to try to get more people to try the cigarette butt to see if damping gives similar results to what I get.

I don't know how the ECU reads the MAP signal - does it take the top value, bottom or average? Is it switched at all pressure readings (i.e.: does it always have an effect on the ECU) and how often does it sample? every second or minute or every revolution? my guess is it samples instantaneously electronically every revolution and if the signal is fluctuating due to induction pluses that the instantaneous reading may vary by 20% - depending on what time it reads the pulse.
How the ECU copes with this to deliver a smooth running engine is a bit of a mystery...but it obviously depends on how much the MAP signal coefficient modifies the algorithm

[Ducman]

I don't want to jinx myself by saying this but my 907 (20K mi) runs well with none of this bullshit so all I can add is no they didn't all originally suck, though this is a common complaint.

[Laddie]

I don't want to jinx myself by saying this but my 907 (20K mi) runs well with none of this bullshit so all I can add is no they didn't all originally suck, though this is a common complaint.

I didn't think they could be bad in "as new" condition...

this leads me to wonder if there is a baffle in the air box or something that gets chucked inadvertantly or for the sake of a bit of performance...something that you still have on yours...

I know I sound like I'm hung up on the vacuum thingy but there's not much else I can pin it down to. I would expect mechanical problems would be evident most of the time, not intermittent - and there are too many similar engines that run well but with different EFI. so my money is on the EFI.

I half expect the root cause will be at the bottom end and the timing gears...I guess that the bearings and teeth wear (maybe still within tolerance) but that the associated lash / freeplay allows any misfire condition to slap around a bit more than a tight new engine. Maybe you engine is either tight enough or well made enough that the problem will not manifest...

whatever it is the bike has cost me well over $4,000 in parts and pieces - with the new fix always being just around the corner...


I hope you don't suffer the problem. It really detracts from the enjoyment of owning this classic bike. Good luck.

[mrinflux]

I don't want to jinx myself by saying this but my 907 (20K mi) runs well with none of this bullshit so all I can add is no they didn't all originally suck, though this is a common complaint.

Ducman,

I'm with you. I"ve got 3 907ies. I'm running racing chips, free flowing air cleaners, and aftermarket cans on all of them. One of them has a worked engine, with high compression pistons, radical cams, bigger valves, and port work. None of my Ducs stutter, hesitate, or run rough. If any of them did, I'd get rid of them. For me, the esthetic of machinery dissapears if the machinery doesn't function properly.

Elton

[Finnpaso]

Finnpaso, you say you "tuned" your engine with FIM software ... does that mean you programmed your own chip to get it to run right? Or just installed one with increased fuel through whole range?? I am not sure exactly what you did..

..and did you have the hiccup problem before you tuned it?

1. I get normal FIM (907) chip and it was tuned with FIM software(my friend have that software and he did adjustments with latop) in hole range 7.4% richer, but not in dynorun, only by driving it. It was fastly done with my friends FIM software. Before that i installed AMB. Same time also ported head, ST2 cams, open flow in inlet and exhaust, etc.. and before FIM chip i drive it with FBF chip, to what i wasnt satisfied(not enough rich mixture=no power), same also with original chip. Fuel consumption was rised only little, so i dont care of it, cause more power need surely more fuel.

2. Not anykind of hiccup problems ever. Surely i adjusted injection first, before all these modifications. It function well before modifications and better after, but with more power, what i wanted.

...and these Ducatis have that "character" :laugh: , what is sometimes coming from electrics, or mechanical problems, but it "belongs" to Ducati world...have allways been in Italian products..... BUT LOOKS GREAT !!!! :laugh: :laugh: :laugh:

[Laddie]

mrinflux and Finnpaso - you both each have reasonably modified bikes...

between chips, cams and cans - yes, I'd imagine that you'd better have the things running near perfect...I'm sure you'd be pissed off if they didn't...

where i'm coming from is with the standard 907 horse - with the exception of Staintune exhausts and an Ultimap chip - these were fitted when I bought it.
I don't think I'll ever demand the full power output that the 907 can deliver reasonably standard - let alone with cams and valves...I'd just like to get it running satisfactorily, properly (as much as possible) in near "standard" condition.

I want to get the thing running like a clock all the time.

Fast is fine but accuracy is everything. (Wyatt Earp).

My XS1100 didn't handle - but i knew that before I bought it, my TZ Yams didn't idle - but you don't spend much time idling on a TZ. I think it's OK to have the Ducati character, but just expected that there would be a little more refinement in this Italian job...

pass another latte...

[Finnpaso]

Guys, dont take this my comment too seriously now(!!!): I want to say "only", that Ducatis are not easy motorbikes and thats why these dont fit so well to such guys, who dont want to "play and maintain" they bikes with they own hands. Sorry, but this wasnt direct to topic, but i have seen very many times, that some "easy jap bike" is much better to such guys, who dont want maintain/fix/cure problems from they own bike. In Finland here is also plenty of such guys, who have enough money to buy many Ducatis, but they dont know anything about maintainig simple things in they bikes. Its little sad and thats why Ducati club of Finland have divided also to 2 parts: Those, who buy new Ducatis(cant do anything to them) and those, who have older modells and do everything to they bikes. Line between those groups is very high. I dont want to make anykind war of this thing and this was only one comment to taughts, what came to my mind, so NO need to comment this my opinion.

Fabio Taglioni: "I dont want to make easy motorbikes, i want to make difficult bicycles"

Anyway I pray, that Laddie(with hiccup problems), Gert(with better ECU), etc.... can get they bikes to very good conditions, cause seems, that at least You both have plenty of "knowing" and energy to figure out things in Your bikes. I like thatkind behaving alot! Keep going....

[Tamburinifan]

Thx, Antti, and surely not giving up before my bike runs good.

Gonna get sync clocks and carefully sync esp at 3000RPM`s and to be sure, get another check w the Mathesis tool from a second shop that my whole ie system is OK.
Then, who knows what will happen....

[Ducman]

http://jefferies-au.org/MyECU/index.htm

another source

Fast By Ferracci also makes
a chip that some posters have used, but many have since switched to the FIM
version.

Apparently FBF uses the "some is good, more is better" approach to
engineering (if you call it that) their EPROMS. On the Duc EFI systems the
CPU basically does a series of table lookups. On the 907's 6801 based
processor these table lookups produce an injector values from 0-255 to
indicate how long to open the injector -- for a richer mixture, they just
spray for a longer time, for leaner, a shorter time. According to Duane at
Fuel Injected Motorcycles, all that FBF did was to do an across-the-board
bump of all of the values in the table. He claims that if you look at the
table lookup outputs a lot of the time under acceleration you'll see 0xff
[maximum value] outputs when that is really not appropriate based on an
exhaust gas analyzer. The upshot of this is that the bike tends to run
richer and mileage suffers. According to him he does his EPROM tables with
a brake dyno and EG analyzer setup. When running with the FBF chip, too
rich is what seemed to be happening. It wasn't uselessly too rich but it
was noticeable. Side effects of the too-rich settings, however, are carbon
build up in the exhaust and crappy mileage.

[Laddie]

Ducman -

I guess that as not all bikes are not alike, not all chips are alike...nor can you expect they adequately give economy and performance, smooth running and all the good stuff in one chip. They are usually purpose-built - you just need to find out the rationale behind the design...

The "rich" chip may well have been designed by a petrol-head for (say) racing back in the dim, dark ages of EFI technology.
This "more is better" technique also suits Finnpaso as he riched-up his EFI 7.5% across the table and is happy with the results...as for full duration squirts under acceleration - maybe it seemed like a good idea at the time??? (I bet it back-fired when you let go of the throttle!!)

I know the first thing everyone has tried with my 907 is to dial up the fuel somehow to make it run smoother.

In the racing fraternity chips are often revised as performance data and feed-back comes along, but usually no two bikes are alike in modifications - so the programmable systems (like a Jeffries) are a must. Similarly, you might find that a chip has been designed but is no longer supported due to lack of numbers of users / buyers. I'd imagine they don't sell too many chips for 907s these days - except the dusty ones...

The Ultimap gear is continued to be refined - the latest 907 chip I got from Duane was "new" only about 10 months ago - nearly 15 years after the 907 was built...at that time I was doing a process of elimination to solve my problem and I figured the ECU and chip needed to be a bench-mark steady platform. I don't know the map was modified significantly but the chip itself was - it's a piggy back style. (looks like two centipedes fucking). The fact that he's still developing products for a machine like a 907 is encouraging...a lot of other parts (like the ignitors) are unobtainable, let alone improved...

Duane has been very helpful to me with testing my ECU and helping me with chips and is certainly well respected here in Australia in EFI circles. I'd be cautious about pegging one brand against another (and quoting part of the discussion) as a basis for deciding what will work well and why. [Particularly in open-forum]

[Finnpaso]

Laddie, keep going on with Duane and with 907 chips! I have heard, that he is great guy and helpfull.... Pitty, that i really dont know his @mail address to ask some questions from he ;-((( If someone know it, please send me PM!

[Tamburinifan]

Pitty, that i really dont know his @mail address to ask some questions from he

I guess there is a good reason why he doesn`t have a public email adress...
Quite a few us would like to ask Duane & a few others some questions...

[Laddie]

Duane Mitchell
ultimap@bigpond.com

[Tamburinifan]

Laddie,
do you know if it`s OK f us regular farts/amateurs to to mail Duane?

Regards