TPS bench test!

Discussion in 'Technical Help' started by Greyman, Feb 17, 2014.

  1. No problem getting it reset, please pm me your address and I'll post it to you with some return postage. I'm in Brentwood Essex btw.

    Many thanks for help. Keith.
     
  2. No worries, this will be fun to see how it graphs
     
  3. Im interested in this even though I don't understand all the technicalities , thanks guys ,makes a change to read techy stuff like this :upyeah:
     
  4. Hi Guys
    O.k we have a graph of Streetfighter TPS that he sent me for test.



    Edit: comments added: This is 3 runs, a little offset from each other purely because of a small slop in the take up of the drive from my stepper motor. It may not be very clear in this graph ( i can provide a larger view if anyone wants it) but there is a flattened off area just after the change in angle. I dont know where this would appear in the rev range or whether it would be detectable as an issue at that point.
    Other than that this looks like a stable response.

    Streetfighters TPS.jpg
     
    #24 Desmoboy, Feb 28, 2014
    Last edited: Feb 28, 2014
  5. Top Bloke Desmoboy:upyeah:. Yep that's working by looks of it.

    Many thanks for your help.
     
  6. No Worries it'll be back in the post tomorrow.

    I have just had a look in more detail and the flat area is at most( trace 2) 4 data points which is 1.8 degrees of throttle movement. I would imagine this creates a bit of a dead spot where response to change of throttle has no effect. whether this is even noticeable and whether it has any bearing on what you are experiencing i have no idea.
    Having never yet traced a "perfect" TPS i dont know if its always there.

    I'm glad that we have the opportunity to draw on the brains of the dude in California for this idea and now have the means to do it should the need arise.
     
    • Like Like x 1
  7. Good work.
    How do you do this desmoboy.
    Have you hand crafted a rig too ?
     
  8. Yes in a way but its so simple and rustic its not true. However the function is just as accurate.

    I have a stepper motor with a flexible adaptor to which you can fit a shaft in line with the motors shaft. I filed the end of an Ali shaft to key into what the TPS needs, in this case a 8mm x 4mm lozenge shape if you see what i mean.
    Fix the TPS so that it won't move, blue tac actually (to the side of my PC at work !) and run the stepper motor via an Arduino.

    The TPS has 3 wires, 5 volts, ground and the signal wire we are interested in.
    The arduino has a connection that can read the relevant wire on the TPS to 3 decimal places and as the motor moves so the value changes.
    I step the stepper motor a small amount, take a reading and repeat. 222 small steps of .45 degrees each gives a set of voltage readings. Export to excel and graph them,covering 100 degrees of throttle movement.
    Do this a number of times to make sure its all consistent and as you can see i did three runs in this case.

    As it happens i actually take 3 readings at each position (222 x 3 per graph) and average them to remove noise in the signal but i dont think its necessary.
     
  9. Hi Folks,

    Glen at Ron Parkinson's (Colchester Ducati MD) said that my TPS is faulty too. I have a 916Bip & don't want to pay the crazy price Ducati want for a new one, any suggestion on where/how best to go about this, I certainly don't want a used TPS as the one I have has only survived 11000 miles.

    Has anyone tried & tested a TPS from California Cycleworks?

    Another thread on the forum suggests using a TPS from an Alfa Romeo ie, again has anyone actually tried & tested one of these?

    I believe the part required is 28440011B or Webber PF09/04

    I would really appreciate your advice on this matter guys!

    Thanks Rob
     
  10. Rob have a read of post #19 in this thread. Parkinson's thought streetfighters TPS was duff as well and as you can see its good. I wonder what they have done to make that diagnosis.
    Is yours still connected to the bike and if so are you confident to remove and reset it?
    If so send it to me and i will let you know for certain whether its duff or not.
     
  11. Got my TPS back from topman Desmoboy today c/w printout, many thanks mate. Glen at Parkys checked the reading on mine and said he thought there was a bit of a jump in the voltage as the throttle was twisted slowly, he didn't say it was fkd, just suspect and would expect a slower change. He only spent 5 mins on the bike as a favour. Btw my bike has 40,000 miles on it. I bought a pattern fiat/alfa/renault tps ML19925 £25 from ebay. It is not adjustable position type so I filed the fixing holes into slots so it can be adjustable. When I tried to use it the female drive socket in the tps is too large so the male drive doesn't turn it. I was going to put heatshrink on the drive shaft to make it bigger to make it useable. When the bike is on the road next month I'm taking it to Proteam to get it checked out properly and will post the results.
     
  12. Hi Desmoboy,

    Thanks for your reply.

    Yep the TPS is still on the bike but I haven't a clue when it comes to messing about with engines/bikes that's why I have always taken my bike to Parkinson's, been taking it to them every year for the last 9 years. Ive only been doing around a 1000 miles a year on it if that, as I have another bike too.

    It just doesn't run right. I don't think Glen is trying to deceive me by any means (at least I hope not) as he did recommend that I try and source the part from somewhere else, as he agreed Ducati simply want too much for the part. He said I'd find a new TPS on the web for £40-£80, bugger if I can find one.

    Not sure if he tests them in someway or how he came to the conclusion that it is the TPS at fault.

    Can you recommend another dealership for a second opinion? I am between Chelmsford & Colchester.

    Meanwhile I will pop in and see him next time I'm in Colchester and ask him how it is that he thinks the TPS is at fault & ask for some sort of evidence to back it up.
     
  13. Can you recommend another dealership for a second opinion? I am between Chelmsford & Colchester.
    [/QUOTE]

    Ducati Proteam in Stroud isn't too far away. Either ride the bike there or Alec will collect and return for a very reasonable price.
     
  14. Ok cool, I'll give them a look, I will have to wait for a dry day now, I ain't ashamed to admit! I'm a fair weather biker when it comes to my 916, as it is genuine, 11000 miles, just wanna keep it mint, only use it on special occasions, fantastic bike to ride, when running right hey!!!

    Thanks for your help!

    I will let you know how I get on.
     
  15. I have had similar discussions about my 749 TPS which is pretty much (if not) identical to the streetfighter.

    What is the best method of removal as I have had this penciled in for a while on my to-do list and it seems like a few others have too.

    When it is pushed in it is flat and you simply see the two square tabs that sit against the throttle bodies and all I ever read is people saying to "lever it out with a screwdriver".

    Which bit are you levering, the whole TPS through the female part (i.e putting it in the tps connector and pulling) or the edge against the tps where it pushes in and if so, do you have any tips? Looks like a pig if you need to lever it out from the edge and puts me off.
     
  16. I cant help with removing them. Other than to say that they are held on with 2 bolts and are a press fit onto a shaft that is an extension of the throttle body pivot. I hope that makes sense. Other than a build up of road grime there should be nothing stopping them coming away.
    As for good people to take your bike to i would recommend , and in no particular order , Nelly, JHP, Chris CJS . Others will have their own favourites.

    If you have been taking your pride and joy somewhere for 9 years, doing low mileage and it still doesn't run properly i think its time to look for somewhere else.
     
  17. Glad your TPS arrived back in the post o.k. by the way.
     
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