TPS reading wierd ohm values. - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

jafero · 03-10-2007, 07:50 PM

I checked throttle position sensor.
According to FSM, TPS should have 2K ohms when gas pedal is released and 10k ohms when gas pedal was pressed completely.

When I tested, it was the other way around. When gas pedal was release TPS had 9.45k ohms and when gas pedal was pressed TPS had 1.16k ohms.

Why is this happening? Could this be due to incorrect install of the TPS?
Since the guy who sold me the engine installed the TPS, I have no way of knowing if TPS is installed upside down or not.

jafero · 03-11-2007, 07:37 PM

No one knows?

Dream240 · 08-06-2007, 08:14 AM

Reviving an old thread.

I'm having this same problem. Here's the wierd part, when I measure the ohms from pins 1 & 2, I get the backwards readings. But when I measure ohms from pins 2 & 3, I get the proper readings.

I'm thinking this aftermarket TPS that I bought has been miswired. Like the wires are in the wrong locations. Mind you I'm measuring these readings with the connector facing me -> 1 2 3 .

So anyone know if I'm on the right track? Do I need another TPS with good wiring?

drftmark · 08-06-2007, 09:28 AM

same problem, someone must have an answer...

Slidin240Wayz · 08-06-2007, 09:57 AM

Can you check it directly off the tps on the throttle body?

Dream240 · 08-06-2007, 10:15 AM

you mean check the resistance at the TPS, where the wires come out of the TPS? Why should that matter?

I'm confused.

I'm starting to think it's that the TPS is miswired. But that would just be the beginning of my woes. I'm also thinking I've got a bad injector.

I think too much...

Kaneda774 · 08-06-2007, 06:37 PM

Don't know if this helps but in working with Megasquirt, a DIY fuel injection computer, the TPS was wired as such

Pin 1 - 5 v ref
Pin 2 - Signal
Pin 3 - Ground

Should be pretty easy to isolate the problem, if you check for continuity between ground and one of the outer wires, the one with continuity is your ground, the other is Ref and the middle should always be signal. Take your reading with ground going to common on your multi-meter and signal going into the other lead. If it's still screwed up time for another TPS,
Check your wiring its probably just mixed up.

03-10-2007, 07:50 PM	#1
jafero Leaky Injector Join Date: Jun 2006 Location: NJ Posts: 129 Trader Rating: (0) Feedback Score: 0 reviews	TPS reading wierd ohm values. I checked throttle position sensor. According to FSM, TPS should have 2K ohms when gas pedal is released and 10k ohms when gas pedal was pressed completely. When I tested, it was the other way around. When gas pedal was release TPS had 9.45k ohms and when gas pedal was pressed TPS had 1.16k ohms. Why is this happening? Could this be due to incorrect install of the TPS? Since the guy who sold me the engine installed the TPS, I have no way of knowing if TPS is installed upside down or not.

08-06-2007, 08:14 AM	#3
Dream240 Nissanaholic! Join Date: Dec 2002 Location: Inland Empire, California Age: 46 Posts: 2,188 Trader Rating: (8) Feedback Score: 8 reviews	Reviving an old thread. I'm having this same problem. Here's the wierd part, when I measure the ohms from pins 1 & 2, I get the backwards readings. But when I measure ohms from pins 2 & 3, I get the proper readings. I'm thinking this aftermarket TPS that I bought has been miswired. Like the wires are in the wrong locations. Mind you I'm measuring these readings with the connector facing me -> 1 2 3 . So anyone know if I'm on the right track? Do I need another TPS with good wiring? __________________ Don't mess with my monkey...he's loaded.

08-06-2007, 09:57 AM	#5
Slidin240Wayz Post Whore! Join Date: Jan 2005 Location: Everywhere Age: 40 Posts: 5,427 Trader Rating: (9) Feedback Score: 9 reviews	Can you check it directly off the tps on the throttle body? __________________ Support Zilvia by purchasing a sticker!

08-06-2007, 10:15 AM	#6
Dream240 Nissanaholic! Join Date: Dec 2002 Location: Inland Empire, California Age: 46 Posts: 2,188 Trader Rating: (8) Feedback Score: 8 reviews	you mean check the resistance at the TPS, where the wires come out of the TPS? Why should that matter? I'm confused. I'm starting to think it's that the TPS is miswired. But that would just be the beginning of my woes. I'm also thinking I've got a bad injector. I think too much... __________________ Don't mess with my monkey...he's loaded.

03-11-2007, 07:37 PM	#2
jafero Leaky Injector Join Date: Jun 2006 Location: NJ Posts: 129 Trader Rating: (0) Feedback Score: 0 reviews	No one knows?

08-06-2007, 09:28 AM	#4
drftmark Zilvia Junkie Join Date: Nov 2005 Location: tx Posts: 524 Trader Rating: (5) Feedback Score: 5 reviews	same problem, someone must have an answer...

08-06-2007, 06:37 PM	#7
Kaneda774 Join Date: Apr 2007 Location: Lyman, Maine Age: 41 Posts: 20 Trader Rating: (0) Feedback Score: 0 reviews	Don't know if this helps but in working with Megasquirt, a DIY fuel injection computer, the TPS was wired as such Pin 1 - 5 v ref Pin 2 - Signal Pin 3 - Ground Should be pretty easy to isolate the problem, if you check for continuity between ground and one of the outer wires, the one with continuity is your ground, the other is Ref and the middle should always be signal. Take your reading with ground going to common on your multi-meter and signal going into the other lead. If it's still screwed up time for another TPS, Check your wiring its probably just mixed up.