748 stumbling / hesitation under acceleration - Ducati.ms

jakemu24 · May 12th, 2009, 8:56 am

I started up the 748 today was having "hesitation issues" when riding at normal speeds. When I turn the throttle the engine stumbled a bit and seemed as though it wasn't getting enough gas or the mixture was off. I also noticed that it was back fireing a lot. This issue is totally out of the blue and I can'y expain it.

I am certain the issue is electrical related. I opened the rear seat cover and knocked on the ECU with my fist, this seemed to fix the problem, but it came back after one day. Any ideas on where to start troubleshooting?

Thanks

Aflac1 · May 12th, 2009, 9:43 pm

I had the same problem with my 748 a couple weeks ago. I had my bike serviced and when I went for my first ride of the season it ran like crap. Riding along and it started farting (back fire) I twisted the throttle and it sounded like she was gonna die starving for fuel. It kept bucking like it wanted to go but couldn't. Stopped the bike and reved it up sounded good took off and again did the same.

Took it to the dealership and they changed the plugs (nope not it) cleaned out my tank and replaced the pump (nope not it)

changed the chip (still not it)

. Put it on the Dyno and did an exhaust analysis and found that it was running lean at certain RPM's so the Tech connected my power commander and did a custom map. It run's allot better but I'm still convinced that it's the ECU.

It no longer is managing the fuel system my power commander is

mfutao · May 12th, 2009, 10:59 pm

Quote:

Originally Posted by Aflac1

I had the same problem with my 748 a couple weeks ago. I had my bike serviced and when I went for my first ride of the season it ran like crap. Riding along and it started farting (back fire) I twisted the throttle and it sounded like she was gonna die starving for fuel. It kept bucking like it wanted to go but couldn't. Stopped the bike and reved it up sounded good took off and again did the same.

Took it to the dealership and they changed the plugs (nope not it) cleaned out my tank and replaced the pump (nope not it)

changed the chip (still not it)

. Put it on the Dyno and did an exhaust analysis and found that it was running lean at certain RPM's so the Tech connected my power commander and did a custom map. It run's allot better but I'm still convinced that it's the ECU.

It no longer is managing the fuel system my power commander is

I could be totally wrong here and am applying knowledge from older bikes/cars. Can't you tell a lean mix by the condition of the plugs and the pipes overheating and turning blue in places?

What RPM range was it running lean at?

tye1138 · May 12th, 2009, 11:34 pm

First thing to think about is; Did it happen over-night, or was it a slow build-up to the issue. If it happened overnight (which it sounds like it did) and its intermittent, (which it obviously is) then you're probably dealing with an electrical issue.

Ducati's don't like to get wet at all, so the first thing I always ask is; when was the last time you washed it?

Munchdog · May 13th, 2009, 12:14 am

When's the last time you changed your fuel filter?

jakemu24 · May 14th, 2009, 9:47 am

I had the 12,000mi service 3,000mi ago. I don't recall exactly what was replaced, but I'm sure this included plugs, filters, etc.

So yes, I think electrical is most likely the root cause. Do you think it would make sense to swap out the old ECU for a new one? I have a fast by ferraci exhaust and chip too.

Also, are there any other electrical items to consider like fuses, connectors, etc?

Aflac1 · May 14th, 2009, 6:16 pm

Quote:

Originally Posted by mfutao

What RPM range was it running lean at?

between 3200 & 4000 also 5000 & 6500

jakemu24 · May 15th, 2009, 9:12 am

I'm not even sure that it's running lean. The issue is present at all RPMs. I really think the bike is starved for fuel.

kaos · May 15th, 2009, 10:12 am

if you feel it's being starved,the fuel filter and tank vents is where i'd start.fwiw i would think if the ecu was bad it would plain die,then come back to life.rather than running poorly.

Barell · May 25th, 2009, 5:38 am

Seems, that i have same problem..
The trottle body and throttle sensor has been set to factory setting and results? NONE...
Have you checked REV during hesitation? In my case the Engine RPM during hesitation are constant, but REV on speedometer are going up and down.
I thing, that the timing gear pick up sensor setup can be false..