V11 Sneeze

[JBBenson]

 

 

 

"Idles nicely then after 30 or 40 pulses gives a violent pulse that seems to stop the engine in it's tracks, I equate this to firing well before TDC and trying to change direction."

 

I had this EXACT symptom. It DID feel like the engine was almost trying to run backwards, sometimes with a weird clunk or banging sound.

 

It was solved by doing what Docc prescribes above, although I didn't do the CO trim, and we don't have ethanol free gas here, so I used Redline SL-1 fuel system cleaner to get any crud out.

 

I would add: check intake rubbers for cracks, and make sure there are no exhaust leaks. The V11 is weirdly sensitive to exhaust leaks.

 

Yes exactly that.

I started going through Docc's check list, the TPS was quite a way out, how do those move?

 

I have a wideband O2 sensor, that's no use for setting the O2 is it?

 

 

My TPS kept drifting, turned out it was the fuel hose pressing against it ever so slightly, remember that we are talking fractions of a millimeter to throw it out, go to post #15 (bottom of page) by me here:

 

http://www.v11lemans.com/forums/index.php?showtopic=18910&page=1

[Cliff]

Cliff, the bike has been parked for over a year.

No, the MyECU has been flawless, it's only recently been suggested that perhaps the CO needs resetting.

 

 

 

There are many things that can affect the idle but mixture is the easiest to adjust. Are you running closed loop?

There is more than one cell in the map that covers the idle. You probably have a column at 1100RPM. A fast idle will also be affected by the next column's settings and this one may not be optimal.

 

I don't think there is a bad pulse but timing jitter from worn timing chain could be a problem. Try putting a timing light on the bike and see how sharp it is at idle. It will probably blur as you rev to 3000RPM. If there is a bad pulse then something is probably visible with the timing light. This will also show in the data from the ECU so have a look at the logs for any diagnostic messages.

 

Please post your map so I can see if anything looks odd

[footgoose]

To add to the speculation,

 

The Tenni has recently developed a sneeze, though I called it a cough. Rare, but there. When hot and upon rev from idle.

 

Before: (ran perfect) stock cans FBF Xover, BMC filter, PC3, dyno tuned.

 

After (coughs) same as above but swapped in Stucci for FBF, and added MG Ti cans. not the Ti ECU, no changes done with tuning yet. Done about 150mi. since swap.

 

Still runs great. Just the sneeze. Obvious to me, a response to the cans. New tune in the very near future.

[Scud]

To add to the speculation,

 

The Tenni has recently developed a sneeze, though I called it a cough. Rare, but there. When hot and upon rev from idle.

 

Before: (ran perfect) stock cans FBF Xover, BMC filter, PC3, dyno tuned.

 

After (coughs) same as above but swapped in Stucci for FBF, and added MG Ti cans. not the Ti ECU, no changes done with tuning yet. Done about 150mi. since swap.

 

Still runs great. Just the sneeze. Obvious to me, a response to the cans. New tune in the very near future.

 

Why not try the Ti ECU (without Power Commander) before changing anything else? 

[footgoose]

 

To add to the speculation,

 

The Tenni has recently developed a sneeze, though I called it a cough. Rare, but there. When hot and upon rev from idle.

 

Before: (ran perfect) stock cans FBF Xover, BMC filter, PC3, dyno tuned.

 

After (coughs) same as above but swapped in Stucci for FBF, and added MG Ti cans. not the Ti ECU, no changes done with tuning yet. Done about 150mi. since swap.

 

Still runs great. Just the sneeze. Obvious to me, a response to the cans. New tune in the very near future.

 

Why not try the Ti ECU (without Power Commander) before changing anything else? 

 

 

 

Yeah, that's the next step for me. The allergic reaction to changes I've made could hopefully shed some light for Roy's diagnosis. I'll swap that out this weekend, and after some miles, report back.

[Kiwi_Roy]

 

 

 

There are many things that can affect the idle but mixture is the easiest to adjust. Are you running closed loop?

There is more than one cell in the map that covers the idle. You probably have a column at 1100RPM. A fast idle will also be affected by the next column's settings and this one may not be optimal.

 

I don't think there is a bad pulse but timing jitter from worn timing chain could be a problem. Try putting a timing light on the bike and see how sharp it is at idle. It will probably blur as you rev to 3000RPM. If there is a bad pulse then something is probably visible with the timing light. This will also show in the data from the ECU so have a look at the logs for any diagnostic messages.

 

Please post your map so I can see if anything looks odd

 

Cliff, I see what you mean

I checked the TPS mV and found it to be close to 450 with the throttle body fully closed, it must have been bumped although I may have had the TPS off over the winter and not

reset it properly, sometimes Ido that sort of thing to answer a question on the forum.

 

When I reset it to 150 then set the idle to give me about 425 the bike ticked over pretty good but ran really rough with more throttle.

 

I'm thinking I may have corrupted the map somehow, I will bring home the laptop and re-load it.

I seem to recall something about zeroing some cells so the bike had better engine braking.

 

Don't get old.