Re: Wot & TPS Attn: Shane

From: Shane Moseley (smoseley@ix.netcom.com)
Date: Mon Apr 03 2000 - 23:26:27 EDT


Bob Tom wrote:

> Shane, do you know of any way to trick the PCM into thinking it is not in
> the WOT
> although throttle is completely wide open and are there any adverse effects
> from this. A few hours ago while searching the web, I came across a site
> which sells an adjustable TPS add-on. I understand what it does but have
> no idea if it is in the realm of legitimacy.

I don't know for sure but I would guess the computer looks for a certain voltage
threshold to be crossed. I'm pretty sure that range is 0.5V-4.5V and I think
0.5 is the closed/idle value and 4.5V (or greater) is WOT therefore the
threshold should be around 4.5V. You could verify that by checking it while
idling with a voltmeter. Bernd - does your scantool read voltages for TPS or
percentages like mine?

You might could rig up a microswitch (like w/N2O) that only gets depressed at
WOT. The microswitch could switch on a resistor that would decrease the voltage
being read from the computer. Oh yeah - the TPS is more than likely just a
variable resistor itself with the computer providing a bias or reference voltage
into one side and then sensing the voltage output on the other side - hence the
variable voltage from 0.5-4.5V. Are you confused yet 8-)

> Thanks for any insights that you can offer. I've got, at best, surface
> knowledge but not enough to get a good feel for the overall picture.

Hey - you are doin just fine. Keep running those good numbers at the track and
don't forget to let us in on some of those secrets 8-))

Tomorrow I finally get to go dragracing again (woohoo - no pinging!!!) - I can't
wait. It has rained for 2 days straight and I'll be devastated if it rains on
my parade - I'd have to wait another week. Ok - where is it NOT raining - and
how far a drive is that?

Latr,

Shane

--
'96 IndyRam-HisIndy-MPI/TB/Pulleys/Coil/Wires/CompTAs
'96 IndyRam-HerIndy-numbered(#142)"Track Truck"
'74 Triple-Black Dodge Challenger Rallye 360 home-brew EFI R&D vehicle
'68 Black Corvette Convertible 427 (For Sale)



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