resetting the TPS using VDSTS

[DucHead]

Hi all.

Written and online instructions for resetting the throttle position sensor for my desmoquattro S4R are conflicting.  Brad Black's instructions are more detailed, so I'm going with them.

I've ordered the VDST software (it should be here next week), so I plan on using it to measure the TPS settings.  The Desmotimes manual shows screen shots of the VDST software which show only throttle rotation in degrees for the TPS.  

Does the software convert TPS throttle rotation readouts and to TPS voltage, or must I also use a voltmeter?  If I must use a voltmeter, it sounds like the leads are on the TPS.  Is this true?  

Thanks.

[booger]

Why not use the instructions for resetting Magnetti Marelli TPS from the Technoresearch website? You may be overthinking this. With VDST a TPS reset is a mouseclick.

[DucHead]

Why not use the instructions for resetting Magnetti Marelli TPS from the Technoresearch website? You may be overthinking this. With VDST a TPS reset is a mouseclick.

Thanks for the tip.

I downloaded the manual, and it looks like a snap.  If I read this correctly, I do not need to rotate the TPS to reach a desired voltage.  Rather, whatever the orientation of the TPS, the VDTS software "zeros" the voltage.  Correct?

[dan-o]

your correct, I just did this on my 800Sie and it works great!!

[booger]

With 5.9 or 5AM Magnetti Marelli ECUs, which is most certainly what you have with your 2003+ S4R, you should open the throttle and let it snap back, and reset following the instructions. You will find that your TPS probably isn't off by much if at all.

[scott_araujo]

With the 5.9 ECU you connect VDSTS, snap the throttle shut, and hit the reset button.  There is no need to measure anything with a volmeter or unscrew anything to adjust it manually.  Those are procedures for the earlier non-linear TPS and do not apply here.

Once you do this a few times it's very easy to remember and having VDSTS is so nice if you do your own maintenance.  Well worth the money.  Plus it's lots of geeky, egg-head fun to poke and prod your motor with a computer 

Scott

[DucHead]

Thanks for the replies!  I should have mentoned that I'm removing the tps to replace a bracket on the throttle bodies, so it'll be off by a bit!  Sounds like you guys got me on the right path, thanks!!

[brad black]

if it's a desmoquattro S4R then it has a non linear tps which is set using the 150mV method.  if it looks like the large black ones on my non linear tps report then that's it.  all linear tps are small round ones.

[DucHead]

Thanks Brad.  I painted marks on the small metal plates that sit behind the adjustment screws.  This allowed me to get the TPS very close to the original alignment.  I then used the VDSTS to reset the TPS.  I suppose that did nothing?

I'll see how it runs later this morning, but I'll also probably get a voltmeter in there and check the voltages.  

When I had the TPS removed, I didn't notice any areas to place the voltmeter probes.  Are they on the front of the TPS, at the sides or at the ECU?  As you know, I have the 5.9M ECU.

 

Thanks,
  Dave

[brad black]

i don't know what effect doing a linear tps reset procedure has on a non linear tps ecu.  hopefully nothing for your sake.  i've never done it because it's not part of the procedure, but so many people seem to insist on believing all 5.9m ecu have linear tps.

you need to backprobe the connector or wires or make little jumper wires to get into the tps wiring - there's not access to them normally.  if you set it so the vdsts display said the same throttle degree opening before and after replacement then it's probably as it was before.  but the only way to know is to do the 150mV baseline procedure.

[booger]

wrong like donkey kong I was
please forgive the inadvertent dissemination of misinformation

[DucHead]

i don't know what effect doing a linear tps reset procedure has on a non linear tps ecu.  hopefully nothing for your sake.  i've never done it because it's not part of the procedure, but so many people seem to insist on believing all 5.9m ecu have linear tps.

you need to backprobe the connector or wires or make little jumper wires to get into the tps wiring - there's not access to them normally.  if you set it so the vdsts display said the same throttle degree opening before and after replacement then it's probably as it was before.  but the only way to know is to do the 150mV baseline procedure.

Thanks Brad.  I had painted marks on the plates behind the mounting screws on the TPS, so it's pretty close to the original position: it starts, idles and runs fine. 

Nevertheless, I'm going remove the plug from the TPS and try connecting voltmeter probes to the TPS connectors.  That's what I did on my Bandit.

wrong like donkey kong I was
please forgive the inadvertent dissemination of misinformation

No problem.  I take most advice cum grano salis.      

[woodyracing]

FWIW I don't think you can get a non-linear TPS close using paint marks, its so ungodly sensitive and the increments are so small you can't even see the tiny movements you have to make to get it set right, breathe on those things too hard while adjusting and they'll go way out of range.  I don't know how you do a non-linear with a VDST but I would find someway to do it properly

[scott_araujo]

Woody's right on adjusting the non-linear ones.  I forget whether it was Brad or LT who said it but the spec is something like 150mV +- a few mV.  According to them it's worth sitting there messing with it for a while to get it spot on to 150 mV because it will run much better.

Scott

[DucHead]

Yes, I will try to set it via Brad's instructions.  The problem is that I can't measure voltage with the TPS disconnected, only resistance, right?  (I measured resistance on my Bandit, not voltage).

Perhaps I could wire two connectors together, plug one end into the harness and the other into the TPS and tap into that?  Off to McMaster Carr...


It's an AMP 3-position connector, but I can't find the exact one.  I guess I could cut the wires and spice in a second connector.  Nah.