Hondata

Hi guys,

I have recently boosted my b18c4 stock block. I am running a Hondata s300 v1 and when I turn the car on, it will idle fine... the issue lies with the TPS. It’s not reading any values when data logging on the sensors section? I have tried 2 TPS on my car, my old one that I know worked and a brand new one. I have also tried plugging the ecu into my mates ej9 with a b18c4 to see if it read anything and it didn’t.

As mentioned above, the car will idle fine, but because it’s not reading the TPS at all, when I try to rev it even a little it’ll just try to die because the car doesn’t know I’m opening the throttle to let more air in.

After trying it in a friends car and it doing the same issue no reading, it makes me think it has to be something to do with the ecu. What I could really do with finding out is if it is likely to be the p28 board or the actual s300 socket?

With all this aswell, if I try to read the maximum and minimum throttle positions it’ll come up with -5% closed and 60% Wide open. These figures will come up the same where eever the throttle actually is.

I have also tried 3 different adapter harnesses to cancel that out.

I have seen a few other threads on other forums from years ago with the same issue but they never got resolved.

Any help at all would be great, if it’s just a faulty p28 then I’ll be pretty buzzing but I’m just praying it’s not the Hondata.

Full engine spec just incase.
Stock B18c4 with Skunk2 Intake
68mm TB with a new genuine TPS.
AEM Fuel Pressure Reg and Walbro 255 Pump
Evo 560cc Injectors
Speed Factory Racing 4 Bar Map sensor

You could try cutting J1 to revert the ECU back to stock map. If you have aftermarket MAP and injectors, you will need to revert those back to stock also. Then try cranking the car and see if it responds to throttle input.

Have you verified the voltages at the sensor plug? Make sure you're getting ground, 5V in, and ~0.45V at closed throttle and ~4.5V at WOT on the respective wires. You can check the ground wire and 5V reference wire with the sensor unplugged, but the signal wire back to the ECU will have to be back-probed with the sensor plugged in.

If you have tried the ECU on a different vehicle it sounds like the ECU is damaged and will need to be replaced. The s300 is probably ok.

DUDE! i was just about to post this! Exact same thing happening to me, I even too my TPS sensor off thinking something wrong with it inside, I removed the tps from throttle body, hooked up my multimeter to check for voltage, the voltage was off a bit, so I made it so voltage was reading .50 closed throttle and 4.5ish for wide open throttle, When I go on hondata to read values for the tps I get 0 for minimum and 60 for Maximum, and as well does not show any value at all when under the sensors tab, just always stays at 0 percent. I have to fight to get my honda prelude started up, idles for about 5 minutes or so then just dies out, the 2nd I give it any fuel it instantly dies out. Ohh and this Ecu is new, just got it from my tuner

when you install the sensor back make sure it fits in between the fork so it will move as the throttle move.

then do the TPS scale.

I just got a new ecu so i think i need to check to make sure my dealer/tuner installed my s300 in it correctly, something about J12 pin?

Is J12 cut in the ECU?

Ok so figured out my issue, I borrowed my friends ecu with hondata s300 and got the tps working again and reads properly, but now with the tune I have the car doesnt want to stay running unless i give it some fuel, idle kinda bounces. So yeah tps issue for me was bad ECU, J12 was cut yes

Having an issue with my tps sensor I believe but would like some advice on the situation. Going to post the datalog and calibration and you can see what I mean. When I go WOT it will stall bad, but if I stay sub 95% throttle it will go fine minus the fact it isn’t wide open. My sensor reads 40 closed and 60 open after I hit the read button. When I back pin the connector with ignition on and closed throttle it will not go below 3 volts no matter which way I move it in the slots. This is a new throttle position sensor recently purchased from autozone. Could it be a bad sensor? The sensor I removed was doing the same thing though. Any help interpreting the data logs or advice would be greatly appreciated thank you. 650 cc FIC injectors

It appears to be an issue with the TPS or how it is installed.

Ok update looked around some more and evidently the positive and negative can be swapped on some ecus. So I swapped the 1 and 3 pins by cutting them and connecting them back and now it reads correctly in hondata when I press the read button. So you are saying based on the datalog it appears to be the tps causing the cut at WOT? Does ignition look OK? Thanks for the help, I'll do some more pulls tomorrow to see if it still stalls at WOT

That datalog cannot be used to look at timing as the TPS was not reading correctly.

Hey I got a pull in with the changes to the tps and it did not stall at WOT. So that is good, need to do a pull to see if with boost it will stall but need to update the piping. As far as this pull does the ignition look OK? Im not sure about this ignition, trying to identify if it's a cheaper unit asap. Thanks for any insight