TPS sensor problem

[mr.prick]

TPS voltage and TPS% will not match.
After a TPS reset
0% = .6v
100% =4.5

With the engine OFF voltage and TPS% are fine,
after I start the car TPS voltage goes down and TPS% goes up and swings. :doh2:

This is causing idle problems to say the least.
The TPS sensor wires to the PCM have 0 resistance. :)

[joecar]

Post a log.

[mr.prick]

Before I started the car 0.6v = 0%
After the car is turned off TPS% = 4.7% @ 0.6v LOL
5675
I'm thinking either the TPS sensor is bad or the ignition wires are
causing interference with the sensor, the problem starts after the car starts.

[mr.prick]

I removed the TPS sensor and found the center "cup" that the TB shaft connects
into is quite loose inside the housing.
TPS volts would read 0 if this cup was not centered.
I could turn the cup to WOT by hand and TPS% would = 0% unless I centered the cup.
Can someone confirm whether or not it should fit tighter in the housing.

[Whodunnit]

Any luck? After my first flash (yesterday) I too am experiencing something similar. Hmmm... http://forum.efilive.com/showthread.php?t=11411

[mr.prick]

I still see 0.4% TPS after replacing the sensor,
it is probably due to RFI.

[Whodunnit]

I still see 0.4% TPS after replacing the sensor,
it is probably due to RFI.

Oh, is it a constant 0.4% at an idle or just in the key on - engine off condition? 0.4% or 0.4V? Thanks for your help!
:cheers:

[mr.prick]

0.4% TPS.
It is not constant,
if I tap the throttle it will read 0% but it will not always go down to 0%.
The TPS sensor appears to be very sensitive and RFI is probably the problem.
A ferrite bead around the TS wires may help.

[Whodunnit]

Interesting, thanks. Let me know how it goes!

[Highlander]

Where you able to find out about this?

[acomp917]

Mr. Prick,

If I needed a known resistance, I would calibrate a potentiometer to .5v. Start the car at idle and see if it reproduces the condition. I don't have spare sensors around.

S

[mr.prick]

I bought a new sensor and still it would read 0.4% with the throttle closed. :nixweiss:
I've heard some people separate the TPS wires from the loom for a fix.

[acomp917]

Mr. Prick,

I can understand how that would benefit in a noisy condition. Some ECU's allow any value to be cal'd as 0% TPS.

FMI, what car or harness or custom are you working on.

Also if you don't mind, how do you like the LC-1? I just bought an older 6 wire and like it, just keep hearing about failures and bad CS. On their behalf, they responded to an email within 24hrs. Their software and SSI-4 are very very good for the money($100). ~10 years ago I would have give 5 time that if a system would have been avail. RacePak was way up there. I'm a CAB...cheap azz bastard. :)

Anyway, best of luck.
S

Last thought, If your ground potential raises above zero a voltage divider(the TPS) will always show that level as the minimum value.

Try running an additional ground wire to the sensor plug ground. If that works, you can't leave it there. You must find the problem. You could create a ground loop if it is just added to a faulty ground.

[mr.prick]

This is an 02 Camaro not a conversion and I have no idea why it does this. :ixweiss:
I changed nothing and I know there are scalers for MAP but never thought about TPS. :doh:
I've reset it to zero but it always comes back to 0.4% @ the same voltage: :confused:
I think there is some resistance in the wire.

I like my LC-1 and other than having to replace the sensor it's been reliable.
Innovates software is the best out there but we don't really need to use it w/EFILive. :grin:

[joecar]

+1 on resistance...

check voltage drop across ground connections.