Any ideas on how I could rig up a TPS sensor on the tii?

[peteinjp]

I have a kind of lean spot in the curve and I'd like to figure out if its something that could be taken care of with slight shaping of the throttle cam (half moon in the tuna can) And I'm just curious and like to mess with stuff. I am using the LM1 from innovatge and I can add input from varios other sources to be logged along with the O2 data. So i was wondering if there were any thoughts out there on what kind of TPS might be good to use and how/ where it might get attached.

[TJW]

I am sure you know how the TPS is driven on a 'modern' car, but if you already know you have a lean area 'presumably at a given rpm' is there a need for a TPS.

If you just want to play around with it you could weld a little stub, shaped to drive the TPS anywhere in the linkage that pivots, I think it would not matter where, even on the firewall linkage, then you could plot your fuel curve with the LM-1

[peteinjp]

Yeah I guess once i get on in hand I can figure a way to connect it. I was thinking about the linkage at the firewall as well.

In terms of the lean condition It is at cruise cruise in 5th under load- say up hill or into the wind. There is just the slightest lean miss fire. the thing that bugs me is that if I let off the throttle a little it gets rich. It should be the opposite. At wot its 12-13 all the way thru the band. Its not really a big deal but I just want to get it spot on. Then again maybe it is and I just don't know what I'm talking about. I do realize as well that in fact the wideband is not telling me the true afr. I use it for relative reference. I do think that on my car it is pretty close and plug readings are conguent with what the lm1 is telling me.

[winstontj]

No idea as to relative space that you have down there but take a look at the exploded of the two. This is the e30 318i TB that I emailed you about. You could litterally take out the throttle plate shaft, cut it and weld it ANYWHERE like TJW said, or possibly rig something up underneath your tii TB. Look at the bolts on the bottom - near #'s 21,22 and 23. Looks like #21 is some type of mounting flange/bracket. Again, no idea what that mounts up against but the e30 M10 TPS has something similar and mounts with two phillips screws. It's on an angle and the TPS mounting points are ovals so you can rotate it slightly. There is a click with just the slightest movement of the throttle. Adjusting the idle could set it off - needing to adjust both the throttle plate idle position with the TPS.

Have a look - maybe this will give you some ideas. This part is of no use to me as the M20 TB I'll be using will surely come with it's own TPS. Could you rig up the M10 TB? How about an M20 TB? Just a suggestion...

[dubois]

I would just enrich it across the board. I would turn the enrichment screw on the pump 1/4 of a turn. (Record this for future reference.). I would think it would be possible to mess with the tuna can cam, as well, but that would be a one way street, unless you can manufacture a few with different profiles (here is an idea for profit).

I had a similar problem once , and 1/4 turn that's all it took.

[ray_]

No idea as to relative space that you have down there but take a look at the exploded of the two. This is the e30 318i TB that I emailed you about. You could litterally take out the throttle plate shaft, cut it and weld it ANYWHERE like TJW said, or possibly rig something up underneath your tii TB. Look at the bolts on the bottom - near #'s 21,22 and 23. Looks like #21 is some type of mounting flange/bracket. Again, no idea what that mounts up against but the e30 M10 TPS has something similar and mounts with two phillips screws. It's on an angle and the TPS mounting points are ovals so you can rotate it slightly. There is a click with just the slightest movement of the throttle. Adjusting the idle could set it off - needing to adjust both the throttle plate idle position with the TPS.

Have a look - maybe this will give you some ideas. This part is of no use to me as the M20 TB I'll be using will surely come with it's own TPS. Could you rig up the M10 TB? How about an M20 TB? Just a suggestion...

The TPS on Motronic EFI with an AFM is not a variable pot. It is basically a switch that is actuated at idle position in order to send a binary signal to the ecu, and another contact towards WOT for the same purpose. U can get a variable pot TPS, one comes with the alpha-n setup as it is a requirement in that system. But I digress.

Cheers,

Ray

[peteinjp]

What cars might be good donors for variable units?

[ray_]

What cars might be good donors for variable units?

Um, I dunno, but u can google variable throttle position switch for some ideas.

Cheers,

Ray

[winstontj]

What cars might be good donors for variable units?

Second that question! Might you know if the M20's TPS is variable? I need a variable unit and I was going to ship Pete the M10 one - don't want to make the effort to ship crap all the way to JPN!

[schmick02]

Well - i found an aftermarket TPS which was cheap (make sure it is a sensor not a switch) - then ground a flat on cap screw to fit the the semi circle spiggot - then tapped a plate in place of the coffee can lid - and voila. Oh yeah - JB Welded the cap screw to the top of the butterfly shaft. been there over 3 years now.

[GetOuttaMyWay]

FYIzzle, Bosch part # 0 280 122 001 is a variable TPS. You can find them on the following cars:

Make Model Year

FERRARI --- 512 95-92

TESTAROSSA 91

PORSCHE --- 968 95-92

SAAB --- 900 95-93

9000 95-93

VOLVO --- 240 93-92,90

850 97-93

960 97-92

S70 00-98

S90 98

V70 00-98

Make Model Year

HYUNDAI --- ACCENT 99-95

ELANTRA 00-96

SCOUPE 94-93

TIBURON 01-97

The M20 TPS is not variable. I pulled mine from a testarossa at the wreckers. Er, actually it was from a Saab. Be sure to check the PN because the other years of the makes listed above are just on/off switches.

[GetOuttaMyWay]

FYIzzle, Bosch part # 0 280 122 001 is a variable TPS. You can find them on the following cars:

Make Model Year

FERRARI --- 512 95-92

TESTAROSSA 91

PORSCHE --- 968 95-92

SAAB --- 900 95-93

9000 95-93

VOLVO --- 240 93-92,90

850 97-93

960 97-92

S70 00-98

S90 98

V70 00-98

Make Model Year

HYUNDAI --- ACCENT 99-95

ELANTRA 00-96

SCOUPE 94-93

TIBURON 01-97

I pulled mine from a testarossa at the wreckers. Er, actually it was from a Saab. Be sure to check the PN because the other years of the makes listed above are just on/off switches.

[peteinjp]

Well - i found an aftermarket TPS which was cheap (make sure it is a sensor not a switch) - then ground a flat on cap screw to fit the the semi circle spiggot - then tapped a plate in place of the coffee can lid - and voila. Oh yeah - JB Welded the cap screw to the top of the butterfly shaft. been there over 3 years now.

What are you using the TPS for? Just out of curiosity.

That is a good solution- Maybe I'll give it a shot.

[schmick02]

Honestly - I'm not sure of the make / brand of the TPS I use. It was supplied to me by the dealer I bought my Wolf-3d ECU from. It;s virtue however is that it was small, had slotted mount holes on the perimeter to allow adjustment of fixing point - and could be reversed to accommodate clockwise or anti-clockwise butterfly opening. From memory I think the Tii swings the opposite way to many standard applications.

Now - just to ensure you;re not wasting time. I think you said your problem was a lean point somewhere in the curve. Assumedly if you donlt have a TPS fitted at present then your primary source of "load" is via a MAP sensor. In this case - fitting a TPS will not affect a lean out at certain map points. You;re better off programming the fuel map. When you are running a MAP sensor and a TPS - generally the TPS is there to enable a momentary enrichment when you transition the throttle openeing - sort of like an accelerator pump on a carburettor. If the leaning out is a momentary problem when you tramp the throttle then way to go.

Otherwise - if your intake system will dive a MAP sensor ok (works on mine with a 300' cam) then you don't want to abandon the MAP sensor and drive the fuel map from the TPS alone. OK for a race application but not good for the road. Similalry - dont bother filing the cam in the coffee can - it will have no effect on anything except the rate at which the throttle opens as you depress the accelerator.

Hmmm - everything I say above assumes you are talking about having an ECU drive electronic injectors. Can;t think why else you;d want a TPS - but if that;s not the case ignore everyhting I say;-)

Mac