Sunday, April 17, 2011

Thottle Position Sensor (TPS) and Throttle Body sync

TPS:  For some time, I have noticed snatchiness at low speeds.  The dealers checked it for me at the 12,000 km tuneup, including the TPS setting (or so they said).  They said "all normal", but I didn't think so.  I checked the FI settings using the dealer mode switch and noticed it said "_C00".  The factory manual and Haynes manual all say that "C00" is normal, but the position of the hyphen is not discussed .

Overseas forums for the Bandit and other Suzukis (GSX650F/GSXRs) all indicate that _C00 (or the same but the hyphen in the upper position) indicates the TPS is out of adjustment.  The ideal is -C00, with the hyphen in the middle position.

Can I adjust it?  With a Suzuki SDS unit, yes.  It is also possible to manually adjust it by slightly moving the TPS unit on the left side of the throttle bodies.  It takes a Torx T20H security bit (with a hole in the middle) to slightly loosen the unit and adjust it by hand until -C00 shows.  It took me about 15 minutes (it's very sensitive) and checking on the SDS shows it is spot on, so this obviously works.

Throttle body sync

I used a Morgan Carbtune:

It's fairly straight forward.  Tank on blocks, run bike until it is hot and the fan is coming on.  Turn off.  Connect dealer switch:

Switch on, and bike will show -C00.  Disconnect The IPA sensor (number 1) and the 4 air hoses to the throttle bodies, replacing with the vacuum tubes from the Morgan Carb Tune.  Restart bike in dealer mode, which will show C13 (IAP Sensor disconnected).

Adjust air screws until all cylinders are the same (using number 2 as a guide).  Reassemble.


  1. I don't think this setting is critical.The TPS is not designed to be ajustable as it has not been designed with slotted mounting holes and the IAP and IAT are in the same assembly.The correct adjustment is via the throttle stop lock screw in between the two throttle bodies.The manual cautions that the IAP TPS IAT should never be removed from the throttle bodies.

  2. Yes, but getting to the throttle stop lock screw is a major difficulty

  3. Hi, i want to ask you something. Why the second cilinder is for guide? I ask you because want to sync my throttle, but in manual i can't find cilider or whatever for guide.

  4. The reading off the second cylinder (second from the left as you sit on the bike) gives the reading to set 1, 3 and 4 against. It's not critical as long as all are the same