Trying to Understand Throttle Body Balance

[LB36K]

Just checked Throttle Body Balance with Tiger Tool, my readings are 80, 77, 77.

And at 3k rpm, 60, 59,59


Anything should know about these numbers? I'm just about to 2nd mortgage the house, boat, airplane
to do the 20k service 

Thank you in advance

[T800XC]

The numbers reported by TigerTool are simply what the ECU is sending. The 'balanced' or 'not balanced' message that you see is also a status signal direct from the ECU. As with other diagnostic software (e.g. TuneECU, Dealertool & TriTun), TigerTool doesn't do anything with the numbers it receives to decide whether the throttle bodies are balanced.

If you follow the TB balance instructions in the service manual you shouldn't go wrong. Most people, me included, tend to do a simple check of the TBs with the engine at idle but with the airbox etc all still connected. The service instructions say that the air box should be removed before doing the TB balancing.

[LB36K]

Super, Thank you for the clarification on this!

[STJIM]

Originally Posted by LB36K

Just checked Throttle Body Balance with Tiger Tool, my readings are 80, 77, 77.

And at 3k rpm, 60, 59,59


Anything should know about these numbers? I'm just about to 2nd mortgage the house, boat, airplane
to do the 20k service 

Thank you in advance

Basically you are checking the flow through each throttle body which is the flow into each respective cylinder.   It makes sense that they should all be about equal - that each cylinder is doing the same work.  There is an adjustment for two TB's so they will match the one TB that isn't adjustable.  The adjustment simple changes the position of the respective TB throttle plate whose position determines the airflow into the respective cylinder.

[digital]

[STJIM]

Digital :

I used an old style VW "floating ball" airflow mechanical air flow meter to balance my throttle bodies.  When I finished, I checked the reading using TigerTool and I got just about the same readings as you are showing above.

It's a little tricky ( IMO ) using the software to make the adjustment since the ECU is constantly adjusting the TB position to maintain about 1,000 RPM while the TB balance adjustment is being done.   It was quicker & easier ( for me anyway ) to use the flow meter.

BTW, I told my friend about this who has an Explorer XT - same TB's as a Trophy.  He was aware of this difficulty since he does his own work.  He is an engineer who works for Volkswagen / Audi at the US Headquarters in Auburn Hills, MI  and he said when the VW / Audi software is used to adjust the TB's on VW /Audi engines with multiple TB's , the software temporarily turns off the idle speed adjustment while the TB balance is performed.   It would have been nice if Triumph had done the same.  Too late now ...... I doubt Triumph would do an upgrade to their software at this point.

[digital]

Sagem Systems
- Idle Fuel Adjustment (%) (open loop motorcycles only).
- Set Closed Throttle Position.
- Set Adaptive Stepper Position.
- Set Long Term Fuel Trim (closed loop motorcycles only).

Keihin Systems
- Reset Adaptions.
- Throttle Position Sensor Adjust (applies to models fitted with and adjustable throttle position sensor only - refer to the relevant service manual for your motorcycle).
- dle Speed Control Stepper Motor Adjust (applies to models fitted with an idle speed control stepper motor only).
- Balance Throttles.
- Exhaust Butterfly Valve Adjust (applies to models fitted with an exhaust butterfly valve only). 

In particular, whenever I adjust the throttle balance, I check the throttle sensor, since the adjustment can vary one way or another.   

[STJIM]

Digital :

I remember you mentioned that before - good thing to do first.   I didn't check mine before I did the TB balance,  but I will the next time I do my valves in 20K miles ( if I'm still respirating ).