Tune / ECU Question

[Stretch]

Ever since my 24,000 mile service (it seemed) last October, my bike just isn't making as much power at wide-open throttle.  

At first I thought it may have just been the switch from a K&N air filter to a more restrictive stock Triumph filter.  No changes were made to the throttle bodies, valve shims, or fuel system (just the filter).  

Then I had another thought.  As many here know, I had alternator / regulator trouble with my Girly out on the road last October.  I was a good 20 miles from the nearest town when I noticed that my voltmeter was on 12.0 and dropping.  I made a bee-line for the nearest major crossroads to find a motel where I could hole up.  

I didn't want to shut the bike off until I was sure I could find a place, and sure enough, the first motel I stopped at was full.  I went across the road to another and confirmed that they did have a room for me before I shut the bike down.  By that time, the voltmeter read 9.5

I hauled the bike home in a rental truck.  Then I did the 24,000 mile service that was due and replaced the stator and regulator.  Voltage is now 14.5 above 2500 RPM.  Good to go.  In the interim, the bike was disassembled for about a month while I waited on parts and took my time doing the service.

I wondered if having the battery out of the bike for a month may have somehow corrupted the off-road tune programmed into the ECU.

It then occurred to me that I did run the bike for several minutes below 12.0 volts, culminating at 9.5 volts by the time I found a place to hole up.  I didn't want to do it, but it was under extenuating circumstances.

When I roll the throttle on in high gear, nothing happens.  I can hear a bit more intake noise from the throttles opening, but the bike just kind of sits there.  It doesn't really stumble or cough, but the power does fall off until I bring the throttle back to normal.  It's like the injectors simply don't throw the extra fuel in there, and opening the throttles creates a lean condition due to the excess air.  It also doesn't idle well when cold.

Will running the bike at 9.5 volts corrupt the off-road tune?  Or worse, have I damaged the ECU?

[Mustang]

the syptom you are describing is exactly what a carbed bike does when it is too lean , when you had her all apart are you sure you don't have something amiss with the air box letting too much air in with the mix ?

[JetdocX]

My advice first off is get rid of that POS K&N.  You can through a German Shepard through that thing.

Next, it seems you got a new tune:  constant speed-variable noise! :lol:

[fano]

My advice first off is get rid of that POS K&N.  You can through a German Shepard through that thing.

Next, it seems you got a new tune:  constant speed-variable noise! :lol:

I think he did.

Posted: Tue Jan 06, 2009 8:23 pm    Post subject: Tune / ECU Question  

--------------------------------------------------------------------------------
 
Ever since my 24,000 mile service (it seemed) last October, my bike just isn't making as much power at wide-open throttle.

At first I thought it may have just been the switch from a K&N air filter to a more restrictive stock Triumph filter. No changes were made to the throttle bodies, valve shims, or fuel system (just the filter).

[abruzzi]

I don't know that tunes are that volatile, but if you have a friendly triumph dealer, they can reload the tune quickly.  If you have the TOR make sure you use the TOR map.

Geof

[Stretch]

I do have the TOR pipe, with the TOR tune loaded by the dealer when I bought the pipe.  They're two hours away, but if all I need to do is reload the TOR tune, that'd be fine.

The fuel starvation at Wide-Open Throttle and the poor cold idle seem to point to lean mixtures across the board.  That's why I'm under the impression that the off-road tune (which makes for richer mixtures across the board) has been compromised, and the ECU is running the engine on a bit less fuel than before.  

If it's not a fuel or software problem... air (quite a bit) would have to get past the throttle bodies somehow to create a lean condition at WOT on an injected bike.  When the bike was apart, I didn't fiddle with the throttle bodies, and the airbox fitment really wouldn't have anything at all to do with the mixture.  So I don't think it's a mechanical or vacuum issue.

I was just wondering if running the bike at such low voltage could have scrambled the code in the off-road tune, leaving the ECU to run in a default mode.

The bike runs well once it has warmed up for a couple minutes, which I do anyway.  I've put a few hundred miles on her since October, and I only notice a change when I really put the spurs to 'er.  When riding like a responsible adult, she's just fine.

[JetdocX]

Software is funny that way.  Go get a remap and see what happens.

[abruzzi]

Just a shot in the dark, isn't there a sensor on the exhaust that regulates mixture?  How about on the intake side?

Geof

[Kiwi Tiger]

I hate to say it but I would rip off the tank and check the seal around the airbox.  Then I would have a good look around for something amis.

[Stretch]

There is a Lambda (O2) sensor in the exhaust that helps the ECU figure the correct mixture.  On the intake side, there is an Ambient Temperature Sensor, a Barometric Pressure Sensor, and possibly others that I'm forgetting right now.

The quirk in the whole equation for me is that the bike was running 9.5 volts when I shut it down, and I didn't start it again until I had finished the 24,000 service, so I'm trying to play detective here and figure if the trouble is a side effect of the regulator failure and subsequent way-too-low voltage, or if it's something that I did (or didn't do) during the service.

Damn, that was one sentence.

I don't think it could be the failure of an unrelated sensor.  The timing of it would have to be too precise... that everything was fine until I first rode the bike after the service, and the sensor failed at that time.  Too much of a coincidence.

This morning I talked with my bud at my fave local shop, NPR Ducati.  He used to be the Parts Manager at Atlanta Triumph-Ducati and knows pre-2006 Triumphs like the back of his hand.  I asked him if running the bike at 9.5 volts would cause problems with the tune program, and he answered "almost certainly".

He's gave me the number of the former Service Manager at Atlanta Triumph-Ducati, who has his own small shop now.  He has his own Triumph tune-installing tool, so I'm going to see if he can reload the TOR tune for me.

As you may have gathered, there was quite a bit of upheaval at Atlanta Triumph-Ducati a few years back, and most of their folks left for greener pastures.

[JetdocX]

If you had a sensor failure, your check engine light would be on.  I missed the part where you did the 24,000 mile service.  It might help to recheck your work there with regard to gaskets and intake sealing before dragging it to the shop.

[Stretch]

I don't believe it's a sensor failure either.  I don't think they are so sensitive to voltage variations, in regard to their survivability.  Naturally, sensors won't function correctly if they don't get the current they need.  

Digital systems, on the other hand, such as the ECU, require specific, internally-regulated voltage at a specific frequency.  When the input voltage drops below the ECU's internally-regulated operating voltage, something's got to give.  In this case, it seems to be the software.

[/End Speculation]

Concerning intake leaks...

Some older fuel injection systems (such as Bosch Jetronic, and the copycat system used on '80's - 90's Fords) relied on a sealed airbox and Mass Air Sensor to meter the amount of fuel used, based on the amount of air flowing through the airbox (measured by the Mass Air Sensor, a glorified flowmeter).  These systems are highly sensitive to intake and airbox  leaks, as that would allow an unmeasured amount of air to enter the intake, essentially bypassing the Mass Air Sensor without permission...

The Mass Air Sensor detects x cubic feet per minute of air flowing into the intake, and directs the Fuel Distributor to send a precise amount of fuel to the injectors based on that airflow and sensed intake vacuum.  But with an intake leak, there is in fact x +  CFM of air entering the intakes, and the Mass Air Sensor is simply unaware of the surplus.  All it knows is to supply the amount of fuel based on the x CFM figure, and the engine runs lean, since it's getting too much air for the amount of fuel going through the injectors.

But...

The fuel injection system used on Girly Tigers instead utilizes a Throttle Position Sensor, which meters fuel according to the position of the throttle butterflies themselves.  There is no Mass Air Meter, and as long as the TPS is properly calibrated (and the throttle bodies are not modified, i.e., enlarged), the ECU meters the correct amount of fuel based on the TPS position, O2 sensor, Atmospheric Pressure, Ambient Temperature, etc.  This type of system is not sensitive to airbox leaks, as there is nothing in the airbox that measures the air flowing through it, and a poor seal means little more than the ingress of dirt where it ought not be.  The airbox itself does little more than hold the air filter and the temperature and barometric pressure sensors, while keeping dirt out.    You could drill holes in the airbox, and the fuel map wouldn't change.  

I didn't fiddle with the throttle bodies, so they wouldn't have developed leaks from disturbing the gaskets.  I also had a thought that the Throttle Position Sensor might be out of calibration, but that seems unlikely since the bike had run perfectly until I ran the battery to nearly nothing.  I don't believe that doing so would affect the TPS once proper voltage was reestablished.  I'm holding out for a TOR remap to replace the one I compromised by running the bike at less than 10 volts.

Thanks for letting me bounce ideas off you.  Several heads are better than one.

Stay tuned...

Extraordinarily bad pun.

[Mustang]

What you are saying makes sense (but only to another geek ) and it sounds like the ecu has gone to limp home mode . It will run and get you there but not like it should , funny though I would have thought a check engine light would come on when the electronics are compromised , please let us other geeks know what you find ! :D

[Stretch]

[iansoady]

What you are saying makes sense (but only to another geek ) and it sounds like the ecu has gone to limp home mode . It will run and get you there but not like it should , funny though I would have thought a check engine light would come on when the electronics are compromised , please let us other geeks know what you find ! :D

That's what I thought as well, although I have never seen any documentation on the limp home mode.