M900ie Fueling Issues with DP ECU

[JPlip]

So, I picked up an NOS DP ECU from another board member.  Bike is a 2000 900ie with Termi Slip-ons, otherwise stock engine-wise.  Currently 4,700 miles on the clock. 

I'm having a bit of trouble getting the bike to run smooth w/o too many tradeoffs (I know these are tough ECUs to get perfect.  Here is what I tried and symptoms:

Stock: OG ECU, stock airbox filter.  Slightly erratic idle, between 1,300 and 1,500, no low rpm stumble, very infrequent backfire on decel, pulls great 5k to 6k rpms, runs out of gas around 7,500 rpms.

Setup 1: DP ecu, stock airbox/filter with intake snorkles removed.  Idles great 1,200 rpm, starts great, minor low-RPM stumble, moderate backfire on decel, pulls like a train above 5k RPMs.

Setup 2: DP ECU, stock airbox w/K&N filter.  Sluggish start, good idle at 1,200 rpm, moderate low rpm stumble, serious backfiring on decel (like an automatic weapon), great pull above 5k rpms or so all the way up.

Plugs look normal so far.  I increase the gap to .035 for better response.  No effect on backfiring issue.  Exhaust seems to have no leaks.  I know the ecu is designed for an open airbox, but with all the signs of lean running so far, I feel like I will detonate the engine if I do that.  My understanding is next option is TPS reset and TB sync w/trim adjustment.  Or, should I just throw in the towel and send it for tuning?  Any suggestions?  Thanks in advance!

[DarkMonster620]

First I would sycnh TB and set TPS then set Trim using a gas analyzer if issue continues, then have it tuned.

[JPlip]

Thanks.  I figured that was the next step.  As I was writing the post, I decided to try putting the stock air filter back on for shits and giggles and keeping the snorkles in place.  Took it for an, ahem, spirited run.  Now we have....

Setup 3: DP ECU, completely stock airbox w/stock filter.  Starts right up, good idle at 1,200 rpm.  Almost no stumbling at low rpms (indistinguishable from stock setup), now pulls very well from 4,000 rpms up through.  There is still some decel backfiring, but its not much worse than stock and limited to 4k rpms.  Vastly improved from Setup 2.

So, do others have some backfiring with a similar setup?  And what is acceptable?   It seems as though restricting airflow is HELPING me here....would it be completely crazy to restrict it slightly more, by say putting tape over 10% of the snorkle opening?

Thanks again!

[DarkMonster620]

Most prolly yhou still a bit lean . ..  being a M900 with, I assume IAW15M, trim has to be set via the electronic tool, if you have such an aftermarket tool, then you can set it up in increments; usually I set it at 24 with 4.0% CO and if needed I adjust accordinly

[JPlip]

Thanks DarkMonster. You are correct, its a IAW15M.  Would you happen to know which diagnostic tool and adapter I need to set the trim?  I just quickly checked the TPS with my multimeter, and it looks good. 150mv at idle, about 445 at key on.  I didn't do a vacuum test, I just wanted to see how far off I was.

[ducpainter]

Have you checked to make sure you have no exhaust leaks?

They can cause backfiring on decel and could be clouding your results.

[JPlip]

DP, I used a HVAC smoke pen to check the exhaust joints.  While it was a little windy yesterday, I didn't see any smoke getting sucked into the joints.  There may have been some air coming out (the wind made it slightly imperfect), but nothing dramatic.  I was more worried bout O2 getting in through the joint.

[DarkMonster620]

Thanks DarkMonster. You are correct, its a IAW15M.  Would you happen to know which diagnostic tool and adapter I need to set the trim?  I just quickly checked the TPS with my multimeter, and it looks good. 150mv at idle, about 445 at key on.  I didn't do a vacuum test, I just wanted to see how far off I was.

You can get this one, Centurion S for IAW15M or purchase directly here, fleabay, if you go this way, just let them know I sent you

Your voltages should read like this, 900Mie 462mV 2.95°, this is copied from Brad Black's website, which also states the following "There was a service bulletin issued for the 900Mie in '00 sometime that revised the TPS idle setting by voltage (not degrees) to 472mV.  This corresponds to about 3.1 degrees.  As far as I can remember, we ignored this pretty much and kept using 2.4 degrees."

[JPlip]

Thanks Dark Monster.  I have Brads page bookmarked already...tons of amazing info there.  I was planning to use his TPS guide for 2v Monsters to get mine set.  Ok, I'll check out the techno research tool.

If anyone has the same bike, and can give any tips for what works best, it would be 

[DarkMonster620]

get the tool and if you need a cheap co meter, http://www.ebay.com/itm/Gunson-Gastester-exhaust-gas-analyzer-tester-/280681199112

this is the one I use . . .

One more thing, due to bike's age, check the valves . . . just saying

[jduke]

Download GuzziDiag. It does everything VDST can do plus it's FREE...Make sure you order the correct cables. There's a thread on on err of the Ducati sites. Google Beginners Guide to GuzziDiag and read it 3 times.

[jduke]

Here's the download site:
http://www.von-der-salierburg.de/download/GuzziDiag/

[jduke]

I found this Beginners Guide on a Moto Guzzi site.
http://wildguzzi.com/forum/index.php?PHPSESSID=2d1570ba4bb537f264112f2991d48fa4&topic=69168.0

[brad black]

set the tps
while on diagnostic tool check all sensor inputs for validity/faults.
replace the fuel filter
check/adjust timing belts
do the valve clearances if not done recently or properly
set the throttle sync (as i believe you americans call it)
set the idle co%

[JPlip]

Wow, thanks for all the help!!  I'll keep this updated once I get the software/cables/tools to make it work.  Brad,  I was planning on making the valves a winter project, as I should be just over 6k miles (initial service point) by then.  Belts are new within 1k miles and properly adjusted using the ducatitech method.

Again, thanks for the feedback.  Hope this helps the next guy with the same issue.