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-   -   High Idle, Popping Exhaust (http://ducatiforum.com/mechanical-technical/17570-high-idle-popping-exhaust.html)

AntiHero Apr 11th 2014 12:28 PM

High Idle, Popping Exhaust
Need some help here. I've had this intermittent problem for several thousand miles. At first it was an annoyance, then a nuisance, then, after I finished my PacNW ride it happened nearly all the time.

High Idle (2-4k rpm) mostly when hot, but a few times when starting from cold
Inconsistent idle (sometimes low/stalls, usually after a start).
Exhaust ‘popping’ or ‘coughing’ at idle, sometimes with high idle, sometimes at normal idle
No issues at normal RPMs/riding
No real consistency. Sometimes hot, sometimes cold, sometimes after cruising on the freeway, sometimes in the city, sometimes not. Sometimes during a cold start, sometimes not. (Though come to think of it, it does happen after filling up more often than not.)

Things I did (some prior to taking it in for service) with no permanent effect:
Removed charcoal canister
Battery disconnect for 12 hours
Manual reset of TPS (turning ignition on and off 5 times).
Replaced throttle housing (tab holding it to clipon had broken off the first one)
Removed/inspected/wiped down RPM timing speed sensor

Problems I found:
1. Airbox seal hadn't been properly seated after the dealer replaced the rear heat shield = meaning unfiltered air was getting into the engine.
2. Oil breather tube had been unplugged from its location on the plastic in the bottom tray (vacuum leak). Assuming this also happened when Ducati Seattle replaced the exhaust.
3. Both the fuel vent lines had been disconnected.

#2 and #1 had me very concerned—basically for at least 3000 miles fresh air was bypassing the filter. This was a particular dealers fault and the heads were replaced.

The popping at idle and the high idle seem to suggest a vacuum leak, but all the vacuum seals check out.

ECU was replaced with the heads, which solved the problem for about 1,000 miles. Now it's back and intermittent. It's driven me and three dealers nuts.

Possible issues I'm thinking:
Sensor that's misreading something and as the ECU 'learns' the symptom doesn't appear until the next start or the next ECU change cycle.


Possibly a component in the system responsible for blipping the throttle as the revs dip is misreading something and causing the issue?

Or O2 sensor?

RTW clock is ticking....

Phl Apr 11th 2014 01:16 PM

sounds like an air / fuel thing

regarding getting rid of air / fuel:
- O2 sensors good? how does the catalytic converter look like? clogged? (need it removed :D ?)
- how well is the exhaust gas recirculation working?

regarding putting air / fuel in the motor:
- gas filter?
- what do the injectors look like?
- you checked the hoses / seals - what about the wiring -injectors (maybe plugs, coils) - sensors (contact spray on the connectors)

- that's all what comes to my mind right now ...

your bike has seen many miles and different climates ... that allows more errors (salt in the air / humidity / dust ...)

outhouse Apr 11th 2014 01:46 PM

Sounds like a air/vacuum leak.

We used to hook up a more sensitive tach, and then use a propane bottle with a long hose.

Strip fairings,let engine idle, use propane and probe all over looking to see if your RPM rises. If it does you have found your leak.

outhouse Apr 11th 2014 01:49 PM


Originally Posted by AntiHero (Post 151695)
Inconsistent idle (sometimes low/stalls, usually after a start)..

With thottle bodies, sometimes you get gummy residue from gas, I normally have to use a can of brake clean on the throttle body and butterfly valve while running and spary it down every few years on my truck. Results are instant if this is the issue.

ScrapperX Apr 11th 2014 02:31 PM

Check out the O2 sensor and its wire to make sure it's not cut or shorting somewhere. I had a similar symptom and it turned out to be the wire for the o2 sensor was rubbing against the new heat shield. The mech routed the cable wrong when they installed the new heat shield.

AntiHero Apr 11th 2014 04:14 PM

Thanks, guys. All great suggestions. I'll try the ones I can't convince my dealer to do on their own.

O2 Sensors are $268 bucks...hope that's one of the ones they do try.

Phl Apr 11th 2014 06:04 PM


Originally Posted by AntiHero (Post 151728)
Thanks, guys. All great suggestions. I'll try the ones I can't convince my dealer to do on their own.

O2 Sensors are $268 bucks...hope that's one of the ones they do try.

I will have a pair left over soon.

Lemme know if you need them in exchange for art.

AntiHero Apr 11th 2014 06:10 PM


Originally Posted by Phl (Post 151745)
I will have a pair left over soon.

Lemme know if you need them in exchange for art.

I think we might be able to arrange something. :)

Claymore Apr 13th 2014 11:17 AM

The Dragon Lady has a "similar" problem. She "idles" high when running through slow traffic in first gear. If I shift to second her revs drop to normal... It makes riding through traffic a real pain. :eek:

Phl Apr 14th 2014 05:19 AM

talked to my tech this weekend. he said, it's rather unlikely that the O2 sensors go bad.
he guesses intake side and first of all recommends a base mapping (that's talking bike connected to the ducatidiag) ...

got a good dealer close by???

(Dennis, check your facetoobs, i sent you a message with his contact, he knows the "good guys" at the dealerships on the left coast)

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