Hondata

Loaded JDM stock B18C 240cc injectors calibration.

Car will not start only cranks. No error codes but was throwing knock sensor code earlier. Car ran fine on stock ECU and with S200 computer J1 cut.

Attached is the datalog recording. Noticed the tach jumps a little when turning key to the ON position and car tries to diesel with key in ON position and/or with key in between ON and accessory positions sometimes when S300 unit plugged up.

who installed the s300 into the ECU?

What ECU are you using this in?

Hondata in CA installed S300.

The ECU is a P28.

So does this datalog tell you anything?

Are you getting fuel and spark?

No spark until it misfires when the key is being moved between accessory and ON positions, at times the plugs fire with the key in ON position.

When CRANKing do not get any spark.

Engine is getting FUEL when cranking.

These are the same symptoms was getting before sent this ECU in to be fitted with S300. Again, the car ran fine when J1 was cut before sending ECU in for the upgrade.

So you are saying that this ECU was having this same problem before it was sent in to have the s300 installed?

Its having the same issue it was having with the S200 before it was upgraded to the S300.

I contacted Hondata about the issues before and I was told to cut J1 to return to stock. When I have gotten the car started in the past on a stock JMB B18C calibration or B18 supercharged calibration it idled for 4-5 min then thte engine stalled and could be be started again.


The ECU worked fine with J1 cut, but with S200 or S300 it fires cylinders in every key position but the CRANK position.

Have you tried starting with a new calibration?

Yes, currently have stock 240cc injectors installed again and car back to stock except for some bolt on intake, exhuast, but no turbo installed.

I have tried the JDM B18C calibration (without any changes) and it will not start.

Is there another calibration I can use, JDM B18C factory one seemed closest since my engine is B18C1 USDM.

It sounds like your ECU may be damaged if it was doing this previously. I would recommend finding a replacement ECU to have the s300 installed into.

With J1 cut on it works just fine this was the test your techs recommended I perform in order to make sure everything was working correctly.

So how can the ECU work fine with J1 cut but when S200 or S300 is used with a tune it goes haywire?

Also you perform simulations before sending a upgraded ECU back so how could this issue not have been detected?

This issue may not show up on a test bench. If J1 is cut it is no longer reading from the external eprom location in the ECU and that appears to be where the problem is. Post a picture of the soldering on the bottom of the ECU.

Are you telling me that J1 should have been resoldered before trying to use S300 in this ECU?

File 1 attached

File 2 attached.

Hopefully you can view the whole thing the file limit would not attach a jpg of 5 mb.