What could cause multiple TPS's to go bad? (S4 n/a)

NoDOHC · 12-15-2008, 09:06 PM

I don't know about you, but I distrust multimeter resistance readings. I would rather watch the voltage sweep and verify that it is linear than attempt to compute the resistive dividing ratio of the sensor (I do understand that the factory service manual lists a resistance spec, but I also know that the ECU reads voltage, not resistance).

If you like, I can try to test the TPS voltage on my bone-stock '90 GXL (which purrs like a kitten on one rotor) right now.

I know you said that the TPS was unplugged, are you absolutely sure that you disconnected all wires to the TPS and that you had a good strong connection with your multimeter leads?(contact resistance is the reason that I mistrust resistance readings).

need RX7 · 12-15-2008, 09:36 PM

I'll try it again tomorrow and double check everything, but when I adjusted my first TPS with the same multimeter it worked fine, until the TPS crapped out for no reason a while later. The part I find weird is that 1) my first TPS went bad for absolutely no reason and 2) one of the TPS's that wouldn't work on my car tested good at the dealer. It just seems fishy to me. I appreciate all your help, can you elaborate on the voltage method so I can try that out too?

12-15-2008, 09:06 PM	#1
NoDOHC The quest for more torque Join Date: Sep 2008 Location: Sheboygan, Wisconsin Posts: 855 Rep Power: 17	I don't know about you, but I distrust multimeter resistance readings. I would rather watch the voltage sweep and verify that it is linear than attempt to compute the resistive dividing ratio of the sensor (I do understand that the factory service manual lists a resistance spec, but I also know that the ECU reads voltage, not resistance). If you like, I can try to test the TPS voltage on my bone-stock '90 GXL (which purrs like a kitten on one rotor) right now. I know you said that the TPS was unplugged, are you absolutely sure that you disconnected all wires to the TPS and that you had a good strong connection with your multimeter leads?(contact resistance is the reason that I mistrust resistance readings). __________________ 1986 GXL ('87 4-port NA - Haltech E8, LS2 Coils. Defined Autoworks Headers, Dual 2.5" Exhaust (Dual Superflow, dBX mufflers) 1991 Coupe (KYB AGX Shocks, Eibach lowering springs, RB exhaust, Stock and Automatic) Last edited by NoDOHC; 12-15-2008 at 09:09 PM. Reason: Spelling owns me

12-15-2008, 09:36 PM	#2
need RX7 Clean S4 Nutswinger Join Date: Mar 2008 Location: Sterling Heights, MI Posts: 485 Rep Power: 18	I'll try it again tomorrow and double check everything, but when I adjusted my first TPS with the same multimeter it worked fine, until the TPS crapped out for no reason a while later. The part I find weird is that 1) my first TPS went bad for absolutely no reason and 2) one of the TPS's that wouldn't work on my car tested good at the dealer. It just seems fishy to me. I appreciate all your help, can you elaborate on the voltage method so I can try that out too? __________________ -Ted -1986 Mazda RX7 Sport [DD/beater]: engine finally let go at 205k. parts car status. -1986 Mazda RX7 base [resto-mod project]: S5 n/a swap in progress.