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Discussion Starter · #1 ·
What's up everyone. Got the EG driving last night for the first time. I calibrated the TPS with the engine off, got readings of -5 at closed and 60 and WOT. With the engine off the TPS percentage sweeps smoothly from 0 to 100 but with the engine running the TPS reads 0 the whole time. This is causing it to cut at about 2k RPM. I have looked everywhere, read at least a dozen posts from people with similar issues, but nobody seems to post what their resolution was. I know my MAP sensor is connected bc it's reading correctly in the data.
When I get to the shop today I am going to check the TPS with a volt meter and adjust if it needs it. I'm just confused as to why it will read and sweep the range correctly with the engine off but wont ready anything with it running. I know a bunch of people have had this same issue, does anyone have a fix that worked for them?
 

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93 Civic HB SI, 95 Civic HB CX
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You'll have to see what you've got when engine is running out at the TPS.

With a multimeter and backprobing, verify good 5v reference still exists once engine is running, verify good sensor ground, all out at the sensor connector itself.

Cut key off, go key on engine off, then check the voltage range of the TPS sweep out at the TPS connector. Record your findings. Then verify at the ECU TPS input you get the same sweep reading. Then start the engine, and recheck the sweep voltage, make sure the ECU is seeing the same input voltage as you did with engine not running.

While doing all of this, in parallel, watch the data parameter on your tuning solution at all times, and see if what you're seeing KOEO and KOER in the tuning solution (0-100%) matches what you're seeing with your multimeter (x-y volts).

You just want to make sure you're seeing the same expression in both places. If the TPS voltage input to the ECU is rock solid in all engine conditions, but the tuning solution disagrees only during engine running, something weird may be going on.

You just want to rule out any issues with wiring/terminals/pins first. These cars are old, terminal corrosion and fretting are common, as are copper wiring broken INSIDE the wiring insulation, making KOEO appear solid, but once engine running and vibrations are introduced, intermittent electrical connectivity issuea appear.
 

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Discussion Starter · #3 ·
You'll have to see what you've got when engine is running out at the TPS.

With a multimeter and backprobing, verify good 5v reference still exists once engine is running, verify good sensor ground, all out at the sensor connector itself.

Cut key off, go key on engine off, then check the voltage range of the TPS sweep out at the TPS connector. Record your findings. Then verify at the ECU TPS input you get the same sweep reading. Then start the engine, and recheck the sweep voltage, make sure the ECU is seeing the same input voltage as you did with engine not running.

While doing all of this, in parallel, watch the data parameter on your tuning solution at all times, and see if what you're seeing KOEO and KOER in the tuning solution (0-100%) matches what you're seeing with your multimeter (x-y volts).

You just want to make sure you're seeing the same expression in both places. If the TPS voltage input to the ECU is rock solid in all engine conditions, but the tuning solution disagrees only during engine running, something weird may be going on.

You just want to rule out any issues with wiring/terminals/pins first. These cars are old, terminal corrosion and fretting are common, as are copper wiring broken INSIDE the wiring insulation, making KOEO appear solid, but once engine running and vibrations are introduced, intermittent electrical connectivity issuea appear.
Thank you very much for the awesome insight. I think you helped me nail it. I pulled the throttle body off and used a power probe to supply ground and 5v power to the sensor. Then we used a multimeter to check the voltages through the sweep. We didn't have it set 100% but we got it correct. .5v when closed and 4.97 fully open. I then used the multimeter to check the wires from the connector to the ECU. The signal wire showed some resistance and while inspecting it the terminal on the sensor connector had some corrosion. I went to the junk yard, grabbed another connector and replaced it. Fired up and now my readings go from -1 to 102, I calibrated it again and I am now getting readings from the ecu. Thank you again, much appreciated.
 
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