Hondata

Wondering if you guys have ever seen this issue before. Ect drops to 145F under boost then shoots up to 260F when you let off the gas. Started off shooting up to 260F under boost late last year. Rebuilt the motor. Thats when it started dropping under boost. Hooked up a independent ect and the car is not actually over heating/cooling. Made a new sub harness for the factory sensor to the ecu with a new ect sensor. Same issue occurs. Wondering if it is the ecu or hondata that is causing the issue. Running s300 v2. Any input?

Here is a log showing the issue currently.

Are you sure that you don't have some kind of pressure switch wired in that is also wired to the ECT sensor that is trying to trick the ECU into thinking it's running cold to add more fuel?

No don't have anything else wired in on that circuit. I've owned the car since it was bone stock. Just a really odd issue.

Here is the first datalog I got when the issue started last year. Popped the headgasket. Figured that was the only issue. But the issue with the weird temp reading has just gotten worse. Weird square wave of an ect reading i have.lol

Try the ECU on a known working car and see if the problem follows the ECU or is specific to your vehicle.

Will do. Might have a car to test it in next week. I'll update after that. Thanks

check thermostat ground?

Bumping this topic back up. So put the ecu in a bone stock car with no issues prior. Same thing occurs. Check out the log and map. Thanks. Guess I'll be trying the hondata board in another ecu and see what happens.


Any ideas?

i was having similar issues @ tx2k17. i changed my sensor AND the connector on the harness, and it fixed my issues. old wires/connector was throwing false readings

I had this issue on a D16 turbo build, first it was flux residue left on the ecu after soldering the hondata header pins, get some good flux cleaner or 99% isopropyl alcohol and scrub off what you can with a toothbrush if you see or can see or feel any flux on the board. the second issue was an actual bad ECT.