I am following this guide on how to reset the TPS... 749 idle adjustment - Ducati.ms - The Ultimate Ducati Forum Basically unscrew the TB Balance Screw as shown here: '03 999 Idle Speed And Adjustment - Ducati.ms - The Ultimate Ducati Forum Zero the TPS then screw in until you get double the reading and zero again. I have GuzziDiag all setup and connected with no issues. Problem is after I unscrew the TB Screw, zero and start to screw back in the reading on GuzziDiag doesn't change. I can open the throttle and it will read a max of 85deg as it should or increments inbetween, but the reading will not change no matter where the screw is. What's do you think could be going on? Context: I am looking to do a TPS reset as the bike is not idling and cutting out if it doesn't have throttle input. I want to eliminate the TPS as the issue and move on to attempt a balance of the throttle bodies.
You understand you are not trying achieve 0 TPS. You set the TB to zero using the screw. Reset TPS value shows say 2.3. Adjust the screw so that throttle causes TPS value to be 4.6. Then reset TPS and it should now be 2.3
More on the subject BikeBoy.org - DucatiLinear Throttle Position Sensor setting notes for all models 08/08
It's a good article, I'd read it but not understood, now having done it I get it. I didn't wind the air bleed screw out on the front throttle body perhaps, surely that shouldn't cause me to not get any change in reading?... Also as I back the screw out the angle doesn't change on the diagnostic software, something's going on...
In the second link I provided the one that says tb balance screw. I'm not backing out the air bleed screws...
The balance screw won't move the throttle/TPS reading. The throttle stop screw is a grub screw in the throttle body. It takes a 2.5mm Allen key. The pictures look to be focused on the flat head screw?
@nelly yep I am winding out the flat head screw labelled tb balancing screw. The main protagonist in the 3 photos. Where is the 2.5m grub screw located? I can't see it anywhere. Also what are the implications of me messing with the screw that I have...?
Iirc on the 999 it's on the lhs of the rear throttle body. It's covered with yellow anti tamperproof paint. You will see it screws thru the body on to the linkage. Now the balance screw is out of kilta, the throttles will need balancing. Do the adjustment with air bleeds screwed all the way in so you're adjusting mechanical balance only.
Thanks nelly. Today I will buy a length of clear tubing as described in the link above and try and balance them. One question, where do I plug the end of the tubes? I can't see any external valves....
Actually I found your previous response to this question here, I will have a look and post a pic of where I think they are... (based on my previous efforts I am not going to assume anything) 2005 999 throttle body adjustment | Ducati Forum
Photo by Joel Ippoliti - Google Photos Do I remove this Allen bolt in the side of the manifold and insert the vacuum tube?
I was planning on making my own manometer as per the above link... Looks like I need to buy some barb connectors and measuring them up they look to be m6. I will report back progress....
@nelly: You seem pretty clued up on all this. My 999 has always had a tendency to stall when you zoom up to a junction (or coming to a roundabout) if you've been scooting along at a fair lick . Obviously not all the time, but it's quite a frequent occurrence and seems to afflict many 999s, 749s. There are those who say they have a remedy. If so, what is it? If you had a 999 which tends to die when hot in traffic (esp when trying to open the throttle after it's been idling at the lights, say) and then refuses to start (it is now a bugger to start from hot, >80°), what would you investigate first?
Right so I've successfully reset the TPS, reconstructed everything back together ready to balance the throttle bodies. I've wound in each air bleed screw (1.25 turns), attached M6 barb connectors to each throttle intake, made a manometer (filled with wd40) and attached it. Looks like this... I started it and the wd40 was sucked into the intake and gone. wtf? Am I meant to only attach the manometer after it has started? Spot anything wrong or should I keep trying...?
