Hondata

Hi,
i have strange thing with my Sensors. Im using two Bosh Temp/Pressure sensor. One for fuel pressure and one for Oil Pressure / Oil Temp.

While mapping, i noticed the Fuel Pressure was jumping between 2,6bar and 4,2bar. I changed the whole puel pump assembly inc. the pump and it didnt changed a thing.
I logged the cold start a few days ago and noticed that on the first 4 Minutes, the Sensors are very stable, AN0 (FuelPress) is very flat.
And after like 4 Minutes, the ignition starts to move the sensor is reading the jumping values. Look at the attached datalog or the pic.

Ive connected the +5V Source from the TPS wire and Ground is on the Kprov4 Ground on the additional harness.

What could be the Problem?

Your battery voltage is fluctuating by half a volt constantly. You may want to look into that first.

why is that?

It may resolve the other issue you are having.

no i mean how to check what could cause the voltage jitter.
Thanks

You will have to go over the wiring and possibly test the ECU in a known working vehicle and use process of elimination. Typically this is an issue with grounds or the alternator itself or how things have been wired.

How can I improve the ground? Should I run more wires from the cylinder head to the chassis?

Make sure they are in the correct location and that they are not corroded or painted.

Have you found the issue why voltage is fluctating?
I have simillar case that oil pressure signal is very noisy. Is there a way to smooth it using some resitors or capacitors?
Thanks

Hey no. I tried to wire it differently and completele seperate from ignition loom and stuff and tried the different grounding on the ecu but it didnt changed a thing..

I dont know where the Ground issues are. Its a fulkly build race car with stripped wireloom, welded cage and stuff. Its not possible to have the OEM groundlocations so im kinda stuck.
It sucks to be fair.

Hello,

i cant find the issue. You say i have a grounding problem. But how can i fix it? Can i put more ground wires from the engine to the chassis to fix it?

Im starting to fed up with kpro, never had those issues with the link g4x :(