TPS voltage weirdness FD 3rd gen
 

Disclaimer: So I’ve read every every sticky and useful thread I can on the throttle position sensor and I’ve tested the thermowax and also adjusted the fast idle cam as per the FSM. I’m running the stock ecu along with only mod being apexi twin filters. I have replaced the rats nest With silicon hoses and replaced faulty solenoids.

Questions:

1. Do the tps voltages change based on the input from the ecu based on other sensors?
2. How far cracked open should be the lower throttle blade be?
3. Is my tps broken?

I put the tps on the throttle body I place it on the tabs at the highest points. Orange arrows on TPS picture and blue arrows on the TB photo.

When I measure the voltages when the fast idle cam is disengaged I have the following voltages which seems way out of spec. They aren’t even within 5 volts of each other. These are the lowest voltages I can get when adjusting the tps when on the throttle body with the screws loosened.
Narrow: 1.4v to 8.3v
Wide: 0.7v to 7.4v

I plugged the tps in without it being connected to the throttle body just to check it was capable of measuring voltages as low as the factory range eg. 0.3v at closed which it can.

It seems like the tabs are in the wrong position so they measure the incorrect voltages.

Just to note I’m simulating a warm engine by disengaging the fast idle cam manually and not warming the car up. I have tried warming the car up with same results but not after adjusting the fast cam.

https://cimg9.ibsrv.net/gimg/www.rx7...8430b2721.jpeg
https://cimg0.ibsrv.net/gimg/www.rx7...c0fbbbc4a.jpeg
https://cimg2.ibsrv.net/gimg/www.rx7...2c194362e.jpeg
https://cimg3.ibsrv.net/gimg/www.rx7...785044111.jpeg
https://cimg4.ibsrv.net/gimg/www.rx7...f375b64a0.jpeg
https://cimg5.ibsrv.net/gimg/www.rx7...db3d2e16e.jpeg
https://cimg6.ibsrv.net/gimg/www.rx7...5ddbffe8c.jpeg

I have VERY limited experience with the FD TPS personally. If someone experienced doesn't chime in with direct answers, go to the 3rd Gen Tech section and do an advanced search using 'TPS' in "Titles only". I just did and coughed up ALOT of threads. Should be something in them that helps, including a substitute for (IIRC) the NLA OEM TPS.

I've done all that and just did it again. I'll go post in a few other threads to get my access up.

i agree, check in the 3rd gen section.

As I understand it, the tps is only fed 5v. With it being a potentionmeter, based on throttle input it will let through varrying amounts of that 5v input. With 5v being the INPUT you cant have more than that at the output because....... science. The 5v being SENT to the tps doesnt change. It's always 5. If you have more than that going in then you may have a wiring issue. Even with the tps completely removed and turning the thing by hand, it should cap out at 5v.

^Yep. Page F-182 in the FSM has the TPS parameters

cheers for the clarification, that’s what I thought but it baffled me that I was getting higher voltages. I’ll check that out and let everyone know how I go.

Well I don’t like to blame the tools but the multimeter I am using had a dying 9v battery. It was registering 18.4v on the 12v battery. Never seen that before, swapped it out and now all the voltages are right. I’m going to buy myself a better multimeter.

TPS now I’m spec but the car is still running like crap. I’m now thinking it’s the injectors. I had them serviced but the car just runs really rich since I’ve put them back in.

Thanks for clarification, it helped me move on.