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If I recall correctly, Ron may remember better, but I did make a new plate, with relocated tps mounting holes. Worked, got the volts to .45. The issue (as I remember) was with bike running @ idle. I was "running out of steps with IAC" and couldn't get everything "happy". I made the new plate with a hole saw, cutoff wheel, and a couple drills. Easy enough, but I ended up going back to stock unit, once I did the flashlight trick.
In the images, the new one is on top. Note relationship of the small tapped holes in relation to the countersunk ones.
Not sayin this couldnt have worked, it just wasn't right. And I got scolded LOL, if I remember correctly. And, to be fair, it DID make a difference when I made it right.
John
As I recall, yours was higher then desired as well. Scolded is harsh. Might have been a suggestion, LOL. The need was likely due to sight variances between the stock throttle shafts and the upgraded shafts as in blade slots and flats on the shafts. Very sensititve area and a few tenths off here and there can make big tps voltage changes to stock TPS mounting holes.
Ron
 

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Exactly what I was telling above with my bad english. I measured tps flats from the original shafts and made tiny error there and I need to drill larger holes to TPS so I got it to 0.4V with my new shafts.

Different ECM's might have slightly different voltage interpretation. DTT VRFI appears to have good range 0.37-0.43V, fair 0.30-0.80 and bad is out of this. One thing where DTT TPS voltage measure online page comes handy. It is very easy to adjust and tight TPS screws when you see voltages at the same time. It tends to be so that tightening screws will still affect to voltages tiny bit if want to be precise. On the same TPS measurement page you can also see that full throttle can be achieved. Also smooth operation can be verified if worn TPS potentiometer starts making some noise.

One observation for those whom it might concern is that rear blade might suffer from slack due to axially loose linkage ends. Too big tolerance there. It might be wise to add thin shim washer under lock rings. Of course properly adjusted rear blade stop screw might help this too but personally I do not like that kind of slacks. I do not know if rear blade can suffer from flutter when idling. Perhaps not. When throttle is opened this slack is not really problem because it is always in the same side. However it might little bit affect to good blade sync.
 

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The position of the blades at idle is kinda irrelevant. The idle air is controlled by the iac. The volts are the important factor. As long as too much air is not being allowed in by the blades, which was the case with mine, when I made the new tps mounting plate. I was "running out of steps " meaning the iac couldn't close enough to control idle. Hense, the flashlight trick, and then going back to stock tps mounting plate.
It IS very important coming off idle that the airflow (1/4" drill shank trick") that at low tps (off idle) there is equal amount of air is going to f&r. As plates open, especially with boosted, say to 25% open, its important these be equal. After 25% or so the laws of physics (and less restriction) the pressure (you'll be on boost by then) will be equal by then.
John
 

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Discussion Starter #24
As I recall, yours was higher then desired as well. Scolded is harsh. Might have been a suggestion, LOL. The need was likely due to sight variances between the stock throttle shafts and the upgraded shafts as in blade slots and flats on the shafts. Very sensititve area and a few tenths off here and there can make big tps voltage changes to stock TPS mounting holes.
Ron
Ron (as usual) you hit the nail on the head. I believe the angle of the flat edge that goes into the TPS on the Holy Moto shaft is off a bit. This presents a big problem.

Before I lose my mind....is it possible the blades are made specifically for each TB bore? I ask as I have no idea which blade I took out of which bore at this point (too much crap on the bench...).

Another data point: I removed both blades from the TB, then adjusted the front adjustment screw (with the shaft only installed of course) and was able to get to .45 V easily. I then put the blade back in and can't get past .57 V. Going to try the other blade in the same bore next......

Starting to suspect this is a losing battle with the shafts due to inaccuracies (and frankly not the first time I've been burned by HM's lack of accuracy......).
 

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Hang on Freudie. You are not loosing anything yet. One thing which is sure is that shafts and flats are not individually made for different bores. That small error which there might be is easily compensated by drilling larger fixing holes in TPS sensor. I have made those shafts lately and made minor error there with the angle but it did not affect so fatally. More problematic is to get blades center in the bores so they do not restrict closing. I used thin shims around blades and dribbled them to center before tighten blade screws.

In generally microcontrollers control theory there has to be always some hysteresis in the system. There is no single voltage (0,40V) which presents 0% throttle position for the ECM. Voltages coming from sensor varies all the time bit (some noise) and therefore there is range of voltages when ECM converts into TP 0%. Otherwise ECM would jump around fueling charts which would be nightmare for controlling things. TP 0% for VRFI appears to be 0.3V to 0.8V. Do not know what is the range for Delphi. So 0.4V is nominal zero point.
 

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Discussion Starter #26
Ok, more data:

After speaking with John today (always helpful!) I did another look at the blade alignments in the bores. Not ideal, but as good as I could get it.

So.....here is what I did next:

I removed the front throttle blade from my donor/spare TB. I did this because I was concerned that I had mangled the other blades during my several hours of messing with this. My theory was right, the "new" blade went in without a hitch and I am able to get it adjusted so that it's essentially sealing the front bore (I know...it does NOT need that, but hear me out).

At this point I put the single bladed TB on the bike and checked voltage (also had the rear screw NOT touching the rear shaft to rule that out as a complication/variable). I now see around .53 V fluttering to .51 V at times. Better, but NOT the same as stock.

So then I put the rear blade in (from the donor TB as well). Up to .53 - .56 ish....

NOTE: I have the front adjustment screw as far out as it will go, so in other words the front blade is as closed as it's going to get in this scenario. So much so that the front blade is damn near binding in the bore.

ALSO: I swapped TPS sensors, same results...so it's not the sensor (not that I thought it was, but we have to rule out everything at this point).

I even went as far as plugging in the bladeless donor TB (and my original TPS swapped to it) and I see an expected .43 - .46ish V.

What does this mean? It means the aftermarket shaft has an error in TPS blade angle. It's enough to cause frustration for sure. IF it was the same angle as the OEM shafts (which it clearly is not) I wouldn't have this tail chasing scenario. Once again, it's NOT a blade alignment issue....I have the front blade (in the single blade scenario) so closed that basically little to NO light is visible between the front blade and the bore...yet still too high a voltage.

I believe the only "fix" at this point is a bit of filing on the TPS mounting holes to compensate for the angle.

As Red Foreman would say, "Prove me wrong!".

And on a related note......I hate this part of R&D. Too many variables = tons of testing. What has me most frustrated at this point is it had nothing to do with what I was doing. Reminds me of the lifter plate scenario I had to troubleshoot and modify.
 

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Well J....
If everyone could do it, it wouldn't be worth anything, no?
Happy you've found a solution that works for you!!!!!
Good job!!!!!
John
 

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Great job Freudie! I hear you bro when you say it is very frustrating to fight with secondary things when the original focus is somewhere else.

You are clearly in acceptable window now by 0.5 ish voltages and can live with it. If you want to be precise file those TPS holes and you get easily 0.4... from there. As I told if you had DTT your acceptable range would be from 0.3 to 0.8! I'm sure you're in acceptable window for Delphi too.

Even there is well regulated 5V sensor supply with own ground from the ecm there is still some minor fluctuation (electrical noise) after sensors. With the oscilloscope that could be seen better. In automotive applications there is always electromagnetic interference present by the ignition etc.

Please Freudie keep going with the great original sealing topic. As John correctly said if this would be easy everybody would do that. You are pioneer on this.(y)
 

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For illustration purposes here is one pic from where all the fuzz is about. My mistake was that I measured from stock shafts that TPS flats are exactly 55deg from the blade top plane. Now later it appears that it is slightly more or my blades are still not closing enough. That might be the case because I made new blades at the same time and chose diameter tolerance by shaking my sleeve.

605482
 
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