I can't speak to the TEC issues but the description of the OEM stuff is correct except that three of the four '94-'97 TPS wires should be the same as the '99 3-wire TPS (the 4th wire is simply an additional idle switch).
----- Original Message ----- From: "Martin Eby" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]>; <[email protected]> Sent: Friday, October 31, 2008 2:02 PM Subject: TPS signal and TPS-based boost > This is mostly directed at JasonC, but any and all responses are welcome. > My car is currently about 800 miles from where I am. They guy > working on it is, at my request, trying to implement TPS-based boost > (Less throttle = lower boost target. More throttle = higher boost > target.) on a TEC ECU (TEC-GT if it matters.) > > Here's what he's reporting: > > "I am trying to get the TPS-based boost working nicely. Initial > problem was that the TPS read a minimum of .52V closed and 3.55V > open. The way it works is to hook the TPS up to a GPI channel on the > TEC (already done) and then use that channel to trim the boost duty > cycle map. The way the trim works, however, is that anything from > 0-2.5V will reduce our duty cycle by up to 50%, anything from 2.5-5V > will increase it by up to 50%... so I need to get the TPS to read > closer to 5V at WOT. > > The 99+ cars have a three wire non-adjustable TPS, so from the > factory, where it is is where it is. I have explored a couple of > different options. An adjustable 94-97 will not work because it is a > four wire." > > and > > "One solution would be to physically rotate the TPS to where it will > read higher voltage per throttle input, and drill and tap the > throttle body for the new base setting. This is not a perfect > scenario; once screw would solidly mount to the throttle body, the > other would be used with a little fabricated bracket to make sure the > TPS physically stays on the throttle body. However it would result in > the numbers we are looking for with no electrical gizmo action (WOT > reads 4.88V)" > > and > > "The GPO trim function is set up in the firmware, there is no way to > change how it responds to the voltage... so anything below 2.5v will > decrease duty cycle, and anything above increases. You can't change > the negative/positive value set point, 2.5 is the magic number." > > The car is a '99. My question are these: > 1) Does this sound right to you? > 1a) The stock TPS doesn't read 0-5V? > 1b) The TEC doesn't support "mapping" or even "offset and scale" an > input voltage? > 1c) None of the TEC's input/output map function coudld be used to > accomplish this? > > 2) How did you implement TPS-boost on your car? > 2a) Is the boost signal taken from before or after the throttle > plate? (I would prefer to take it separate from from before the > throttle plate in order to minimize backpressure and inefficiency at > smaller throttle openings..) > 2b) Any problems with reliability or resolution? > > Thanks in advance, > > M. > > _______________________________________________ > Miatapower mailing list > [email protected] > http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower _______________________________________________ Miatapower mailing list [email protected] http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower
