TPS Reads 0 or 1 When Engine Is Running

K-Series Programmable ECU installation questions / support issues
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TPS Reads 0 or 1 When Engine Is Running

Post by kitwilliams1 »


I am finishing up swapping a K24A into my 1991 Honda CRX. I am having an issue with the engine not idling correctly and not wanting to rev above 4,000 rpm. I have a strange issue where my TPS, which is an Acuity Hall effect sensor that I purchased new, will calibrate and give accurate readings when the engine is off, but when the engine is started the TPS reading on the datalog shows 0 when throttle is applied up to roughly 30-35% throttle input. The engine RPMs will go up when I press the throttle pedal but the TPS reading on the KPro datalog shows a value of 0 until maybe 40% throttle pedal, at which point the TPS reading will change to 1. If the RPM goes above 4,000 or so the engine will stall, the RPMs drop to zero and the engine shuts off. The stall may well be related to another issue, I am just starting out my troubleshooting process and the TPS issue is really confusing. When the engine is off I can calibrate the TPS and monitor the TPS readings as I apply throttle and the ECU is giving correct readings from the TPS when the engine is off. The throttle body is a KTuned 72mm unit that I also purchased new.

Any ideas or suggestions would be welcome. I have datalogs with the engine running that I can post if needed.
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Re: TPS Reads 0 or 1 When Engine Is Running

Post by Spunkster »

It sounds like either a problem with the TPS sensor, or a problem with the wiring. You should try your ECU in a known working vehicle and see if it reads correctly. Use process of elimination to determine where the issue is.
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