On today's episode of help me fix the never ending problems I encountered buying a salvage S2000 we have a recurring TPS issue.

The car sometimes has hesitation/stuttering while driving. It happens temperamentally at a certain throttle position. The car came with an aftermarket TPS, noticeable since the damn thing is oriented the opposite direction that the OEM TPS is supposed to. It looks like it may have been an OmniPower unit.

So I replaced that with a Blox Racing unit that claimed to fit the F series and that one was also oriented the opposite direction that the OEM TPS is supposed to. After a few thousand trouble free miles this unit also gave me trouble while driving and eventually threw a code for low TPS voltage as well. I can see the TPS % reading on my diagnostic tool jump around when the issue occurs.

I have a few questions...

What is the best aftermarket TPS option? This doesn't seem to have been addressed since 4 years ago, at which point it looked like the OmniPower unit. Should I try to go OEM?

Is there something that could be somehow breaking my TPS sensors? From what I've read the TPS sensors are actually quite trivial mechanisms so there shouldn't be anything special about an OEM one. This leads me to think that there may be something else getting in the way.

 

Wiring? Check the resistance while you wiggle the wires.

 

I noticed you tested the voltage versus throttle position using an OBDII reader (on another thread). Are you getting consistent, same bad readings or changing readings? I'd imagine consistently bad = TPS problems. Inconsistent = grounding or problem with supplied voltage to the TPS.

Just a WAG...

 

I'll give that a shot.


I haven't actually been able to reproduce the bad readings when the car is actually running. I can look down at the logs and see it when it happens but I haven't tried to reproduce the voltage drop while the car is stationary. It does not seem to reproduce consistently though. I'll give it a shot now that I know the general area where it has happened to me while driving.

 

UPDATE: I haven't been able to drive the car too much but I noticed that the throttle position sensor voltage gets worse over time and I have to re adjust it every few thousand miles. I still have a hunch that the issue is with the poor aftermarket throttle position sensors I have been using that haven't been correctly designed/oriented for an F20C. I just ordered the OMNI Power F series throttle position sensor that I have confirmed is oriented the correct way, after calibrating the voltage on one last night. After that is installed and I have driven a few thousand miles I will update this thread.

 

Do you have the original Honda OEM TPS? Sub it in & see if it solves the problem(?).

 

The car I bought came with an aftermarket TPS. I have a totaled car with an OEM TPS but I don't want to separate it right now.

 

Ugh. What's a good used one go for? Like $100-200? Expensive experiment. Seems that would be the only way to rule-out bad TPS...

 

I can't seem to find used OEM TPS ever. The OMNI Power runs about 60$. I am pretty confident that the OMNI Power TPS should solve my issues as many one the forums have used it as well. If all goes south I'll cut off the OEM one I have laying around.