Page 1 of 2

s300 crazy sensor spikes

Posted: Sun Jun 23, 2024 6:57 am
by Nick8434
HI I am new to forum I have an issue going on with my car it's a 94 civic with a d16z6
the engine is very heavily modified its a turbo car. My issue that I'm having is while datalogging I will get crazy sensor readings (images attached below). I am in neutral with the engine idling, and it will show 9000+rpm crazy high map reading in the hundreds of psi, vss reading while I am not moving, and I have unplugged the vss as well and will still get the readings of crazy speeds. It will also at times just say I have 17 error codes but doesn't show any error codes when I check. tps will also read than not read. I have a rywire harness with the sub harness I have 4 grounds on the car battery to chassis, thermostat ground, transmission to chassis and valve cover to chassis. I have 13.8+ volts when running, I also have 12+, ground, and output from the ELD 3.5volts at idle as and when running and if revved Eld will change. I do not have onboard datalogging selected I am all updated on hondata software as well. I have gone and unplugged any external sensors I have, as well as removing iac, iat, etc., fan switch etc. to see If I had a sensor shorting causing a short, I have ran the car with just the coils connected injectors and tps and map connected and same exact problem. I have checked all the ground and power to the ecu as well and have been spot on. Also, when having the car running and looking at the live data it does glitch and is not a consistent smooth reading. The COP was done from burton racing 2 months ago and the socketing of the s300 I do not Rember, I did have burton racing test the ecu and they said all was good with it. This is also the first time the car has ran in 2 years .
Thanks for all the help !

Re: s300 crazy sensor spikes

Posted: Sun Jun 23, 2024 8:04 am
by Nick8434
also wanted to add that the j12 is removed as well and I am on s300v3 and serial number is 41514 on the board and this is a p28ecu

Re: s300 crazy sensor spikes

Posted: Tue Jun 25, 2024 8:47 am
by Spunkster
If you go back to running without the COP and just use a stock distributor, does the problem persist?

Are you using resistor or non-resistor spark plugs?

Re: s300 crazy sensor spikes

Posted: Tue Jun 25, 2024 12:09 pm
by Nick8434
I am using resistor plugs and I have not tried the distributor since I do not have another distributor. I'm not sure if I can even unplug the board in the ecu if the distributor will then work either since I know they have to socket the board.

Re: s300 crazy sensor spikes

Posted: Tue Jun 25, 2024 12:19 pm
by Spunkster
You need to test that first.

Re: s300 crazy sensor spikes

Posted: Tue Jun 25, 2024 12:48 pm
by Nick8434
okay I will get a distributor and see what I can do and get back I appreciate it

Re: s300 crazy sensor spikes

Posted: Tue Jun 25, 2024 5:22 pm
by Nick8434
I got a distributor on the car and it did the exact same thing with the cop removed

Re: s300 crazy sensor spikes

Posted: Wed Jun 26, 2024 8:59 am
by Spunkster
Have the capacitors been replaced in the ECU?

https://hondata.com/accessories/capacit ... uage=en-gb

Re: s300 crazy sensor spikes

Posted: Wed Jun 26, 2024 11:59 am
by Nick8434
there were inspected at burton racing and I was told they were good

Re: s300 crazy sensor spikes

Posted: Wed Jun 26, 2024 12:14 pm
by Spunkster
If they have never been replaced, then they are at least 15 years past their expected lifespan and should be replaced to see if that resolves the issue.

Re: s300 crazy sensor spikes

Posted: Wed Jun 26, 2024 12:58 pm
by Nick8434
okay thank you

Re: s300 crazy sensor spikes

Posted: Sat Jul 06, 2024 7:28 pm
by jk_unless
I'm having the same issue even though my resistors have been replaced by Burton racing. When a datalog spike shows a high timing value is it actually giving the engine that much timing?

Re: s300 crazy sensor spikes

Posted: Mon Jul 08, 2024 1:03 pm
by Spunkster
resistors or capacitors?

From Help, About, what is the version of software you are using?

Re: s300 crazy sensor spikes

Posted: Tue Jul 09, 2024 5:27 pm
by Nick8434
So, I ended up getting a reman ecu and new hondata from burton racing and I am still having the exact same problems I can even go as far as unplug the entire engine harness and will still getting the crazy spikes

Re: s300 crazy sensor spikes

Posted: Wed Jul 10, 2024 9:05 am
by Spunkster
From Help, About, what is the version of software you are using?