How To - 749 / 999 Tps Replacement

Discussion in 'Technical Help' started by JC749, Jul 7, 2014.

  1. First off, a big thankyou to Chris W for your help and advice and listening to my seemingly never ending list of issues recently.

    This thread is intended to share my experience, give a few tips and inspire those who are capable to give it a go but are a bit scared of getting stuck in.


    If you follow this thread and mess your bike up in any way, thats your fault. This is intended for information and comment only and sharing of experiences that may help others.

    The Circumstance:

    I had been experiencing running issues with my 749 for the last couple of years but had become accustomed to how it ran. I was riding back from a meet at Long Itchington Diner one night and the bike was running so bad that i just had to sort it out. I had a few issues and ended up replacing a coil and crank sensor and things improved but I was experiencing a huge flat spot between 4-5k rpm. on the gas it would almost stop and if you opened the throttle quickly it wouldnt react and then catch up. There were quite a few symptoms but this was the most evident. It also had very little torque. I did lots of research to identify my issue but my symptoms didnt 100% match any but had similarities with many.

    Before you get stuck in you need to download JPDiag as you need to look at the values and reset it to see if that helps. link: JPDiag

    And have a read of this and anything else you can find on the forum as Chris has very kindly given all the links to the appropriate cables you will need....

    Free Diagnostic Software | Ducati Forum

    I found the value for closed TPS would change and jump about even though the throttle was closed. It wouldnt do it often but I witnessed it a couple of times.

    So, I figured it was time to get it swapped out.

    I firstly used one of the cheap TPS sensors commonly found on ebay and.... it felt like it was made of crap and lasted one minute before it went nuts.

    Chris has found that the OEM sensor can be picked up from a Fiat dealer for about 35 quid and I can confirm that it is identical to the one that i just paid a hundred quid for from Bike Sport Developments.

    Here is more info on sourcing a TPS sensor

    749/999 money saving tip for broken TPS | Ducati Forum

    So, firstly, you need to take all the fairings off.


    You need to remove the front fairing as you need to remove the airbox. The nearside air tube is removed but the offside one is just unbolted and can be left in the rubber mount on the radiator.

    As we are talking electronic parts and fuel, this is also a good time to remove the battery.


    Next up is the tank so you need to remove the rear seat unit. Once unbolted you will need to prop the tank and for this I use a piece of old packaging polystyrene as it wont damage the tank.


    Then next up is the two bolts holding the key cover in place and pull the breather pipes out from the tank. They will be a pain to remove if you have chubby didgets. :D

    Then the tricky part, removing the fuel lines. I hate doing this as one seems to always come off while the other wants a fight. If you are doing this job against a deadline, go to your dealer and pick up 2 new couplings and fuel line clips. They are a doddle to fit with end cutting pliers and prevent this happenning....


    So, tank off and a good time to have a look at bits to clean :p

    The first job before you go any further is to remove the cable tie securing the fuel pump connector wire to the fuel hose running from the airbox as if you forget you will be struggling with the airbox as it will be stuck to the wiring.


    Next up is to unplug the oil tank and loom connector going into the airbox. The oil tank has a spring clip on the right hand side which simply pops off by prying it with a plat screwdriver. Putting it back on is either by squeezing by hand or giving it a poke with the screwdriver or needlenose pliers. Notice the airtube is just resting there, no need to remove as it also serves as the coolant reservoir. The loom connector is easy to get at once the oil tank is out of the way. I simply undid the one clip and let the oil tank hang down. The pipe coming out of the airbox illustrated above you want to rotate down as it will prevent the airbox from being removed as it sits between the frame tubes.


    Then using an extension bar on a screwdriver and a 7mm socket, undo the two clips securing the inlet rubbers to the throttle bodies/airbox.


    Then before you can remove the airbox you need to remove the steering lock. These bolts are loctited and tend to be a pain to undo. Unscrew one bolt 3 or four turns and then swap to the other side as it needs to come off and go on square. A pain to do as you need to use a 10mm spanner due to clearance issues with a socket.

    Take note of the breather pipes either side of the lockset. They form a Y piece and the longest side goes to the offside as it is further away. The breathers then need removing from the retaining clip at the base of the bike as the thick pipe with the grommet on the end is attached to the base of the airbox. The best way of doing this that I have found is to undo the three bolts securing the battery box as this will give enough clearance to push the pipe through the gap and remove.



    Then you want to take photos of the cable routing for choke and throttle cables and remove firstly the choke and then throttle cables.


    The manual states that you need to create slack with the adjusters and then balance the throttle bodies upon re installation but I found the cables could be removed without adjustment.

    TIP! I used a bit of touch up paint to put a mark on the opening throttle cable. It just makes putting it back together simple and you cant mess it up.

    So, after removing the throttle tube, push the cables through the hole in the headlight cluster so they are straight and can be removed with the airbox.

    If all has gone to plan and you remembered to undo the breather and that cable tie to the fuel pump wiring, your about ready to extract the airbox. There is a bit of a knack to it. I have done it a few times now and have it mastered but This is my tip...

    Standing over or beside the bike, put your fingers either underneath both sides of the airbox or as I found easiest, inside the openings of the air filter housing (using caution). Then pull up.

    The airbox will pop off the horizontal cylinder inlet rubber but will still be attached to the vertical.


    So then push forward and twist the airbox slightly. There is a stiffening tube running diagionally across the frame and you need to clear this to get the airbox out. The areas to watch are the oil tank tube which gets caught in the frame so twist it, and secondly the adjusters for the throttle cables. If struggling to remove it, it will probably be these cables touching the frame that is preventing it from pulling out. Take your time and make sure the breather at the bottom is undone.


    Twist over and past the frame rail and lift while pushing those cables past the frame. Note the oil tank pipe pointing down on the right to clear the frame....


    Too late to turn back now.... :Chicken:


    Dont forget to stuff a bit of rag in the inlets. You dont want something going down there.

    Also a great time to clean the engine with a brush :Smuggrin:


    So, undo the screws on the airbox and you get access to the guts. I ended up removing the injectors and giving them a blast with an injector cleaning kit kindly supplied by Chris W - cheers mate :upyeah:

    Unfortunately the throttle bodies need to come out as the TPS wont come out without a fight so next up is undoing the bolts in the base of the airbox.


    This is the TPS. I read lots on other forums etc about pulling this bugger out and if you try (I used caution), this happens...


    The most efficient method for removal that I found was using a thin but strong blade to lever it out, working around its circumference and then pulling with needlenose pliers.



    This is the spigot that the TPS aligns onto. The new TPS has a slotted tube which must align with this slotted spigot before you press it in. If it is not in the closed position, you can cut a wedge in the end of a pencil, insert it gently and rotate it until it matches. Then press it in square, aligning the external plastic tab of the tps to the slot on the right of the hole and the slotted tube to the spigot. I used a very thin smear of Vaseline on the TPS o ring to help it in.


    Then all you have to do is put it all back together remembering which bit went where.

    Take photos of any cables or connectors and you shouldnt go wrong.

    Getting the airbox back on is much easier than removal and once it is in the right location, push it down and you will feel a thud as it seats on the rubbers.

    I have done this job a couple of times now as the first sensor didnt work :Banghead: and I think on a good day it takes me just over an hour to get it all apart. Take your time removing the sensor.

    Once it is all back together, turn the key on and watch the fuel line couplings. They should not be pushing out under pressure and must click into place on replacement. If in doubt, replace them. You have been warned! :Nailbiting:

    Then it is just a case of hooking it up to JP Diag, resetting the TPS and taking it for a blast to see if all that swearing at the f*%*ing airbox when it wouldnt come out was worth it.

    My bike now pulls like a train and without and flat spots for the first time in years :Cigar:

    Again, a big thumbs up to Chris W for all the help - your a legend.

    • Like Like x 5
  2. Great write up
    • Agree Agree x 1
  3. cool, theirs actually a puller for removing those. and a little insight for people on why it costs what it does when your bikes in the shop. enjoyed that. nice one.
  4. Thanks all, hope it helps someone as I was wanting to do it for 2 yrs but kept shying away from it.

    Actually, do you know where you can get the puller? Post it up?
  5. IMAG0354.jpg

    Bet they dont clean all the nooks and crannies when its in the shop.... Slight leak from the horizontal cover plus a load of dirt.
  6. Excellent write up,thanks for taking the time to do it.:upyeah:
  7. yip, fiat part no, should have it on one of my c.d's. at work. if you bare with me i will dig it out. pulled one or two when i worked on them
  8. Part number 71738921
    • Like Like x 1
  9. Well done.Hopefully I will never need to refer to this again.Chris has bailed me out before, he's a top bloke and I still owe him a coffee.:)
  10. found it, just spent the hole day looking for it, new i had it on c.d.rom, never mind i will work late to make up. 71738921. ;)
  11. There's a day you won't get back ;)
  12. teehee, thanks for posting it. i would of got round to it. :upyeah:
  13. Would be interested in any details of the puller tool
  14. thought you beat me to it. a flat hook on two legs if i remember. there was a wee run of issues with the tps on a model of fiat, (erratic idle) if you couldn't cure it with a flash c.d, you had to renew it. if i get a mo i will find it.
  15. have you found it??
  16. nope. i have a bag of c.d roms right in front of me now.
  17. tool no 1871008200
    t.p.s no 71738921
    dont know how to cut and paste.
    flat hook on a puller. a cleaver sod could make one from a chain riveting tool
  18. hello good wright up with pics ( fab )
    mine was a pain to get out and broke just like in your pics and so i put a screw thugh the center and as i screwed it in it just pushed it out square off the shaft it sits on so did not have to take the throttle bodys off
  19. hello could any one tell me the way to go about set the throttle bodys up and in what order and what co reading i should get
    i have done the aprilias be for and they do look alike
    or where to look to look
    #19 woodyman, Oct 16, 2014
    Last edited: Oct 16, 2014
  20. Resurrection!
    Was a puller ever sourced?
    Is the 999 TPS referenced above the same as used the 1098?