Honda OBD1 B Series Setup

[BillyC]

There doesn't seem to be any real info about the setup for a Honda B series so I will post my current setup. If there was some documentation on this it would have saved me tons of time. I still don't have all the details worked out yet but I have the triggers and ignition working correctly. The car starts and runs.

OBD1 HONDA JDM B16A
Stock distributor
Stock ICM and Coil
Cam gears set to stock position
Distributor physical position setup with stock ECU locked at 16BTDC

I will also include the Honda/Acura OBD0 OBD1 OBD2a/b wiring cheat sheet I made for building my own plug and play harness. This sheet also includes the trigger setup in case picture hosting stops working some day.

https://docs.google.com/spreadsheets/d/ ... sp=sharing

Hope this helps someone.
If anyone else has this setup and can share some settings for the stock PWM idle control valve that would also help. I can't seem to get any settings to work correctly there. The idle just raises above the setpoint the moment I enable it.

[BillyC]

I have the car running pretty well. The EMU Black is a truly nice piece of hardware. Very intuitive and easy to dial in. I hope the mods here can get the forums under control. With a little more community support I could see a lot more tuners turning toward this as an alternative to the other competition out there.

To pick up where I left off in my last post about the PWM Idle Air Control Valve...
I set the frequency at 500Hz and dialed the duty cycle back to around 40% base dc. I'm using the PID controller with the stock setting as well as some ignition advance with the PID for small changes. The car idles better than stock. Here is an image of my settings.

I was having repeated issues with a misfire at about 6000 rpm when hot and 4000 when cold. I think I narrowed that down to coil dwell settings. The motor has fresh plugs gapped at .030 (oem recommends 1.1mm or .043). I set the base dwell to about 3.9ms at 14v which is a little higher than most standalone ECU's put this for the OBD1 ICM. I then have the Dwell RPM correction pull dwell down to around 60% by 5000RPM. This seemed to have cleared up it most of the misfire problems but it was still thre everyone once in a while under hevy throttle. I also added map correction that would pull it back even furth to about 88%. This seemed to clear up all misfire issues. This runs the dwell down around 2ms at the low point. It seems like that is right on track for this load/RPM area when comparing to other setups. I don't really like the way the EMU does the coil dwell calculations. I'd rather have an XY graph with voltage and rpm. There is no real circumstance where high RPM and low voltage should try to run dwell higher but there are times when low rpm and low voltage would. The dwell time at high rpm is really being limited by the time it takes distributor to reach the next cylinder.

I'm still having issues with the speed sensor giving me a reliable signal but the tune is to a point where I'm comfortable enough sharing it. See attached.

[BillyC]

Got back to driving the car today and there is still a bad misfire at 6000rpm. It seems to come and go which is really hard to diagnose.

I've attached the log if anyone has any ideas. Here is a screenshot of the spot.

[valsorimkaran]

As far as I can see, your problem is in the Cam sync trigger, from 24 to 3.

[BillyC]

Thanks for taking the time to check that out! It seems obvious now and I should have suspected that. The Honda distributors are notorious for wobbling at high speeds. I'm sure noise could be the problem as well. ECUmaster tech support also replied with some recommendations on how to solve the issues. They are very responsive and helpful every time I send them an email.

Tech support recommended turning off camsync above 4000RPM. As far as I can tell it was a great fix and the car runs perfectly now. I'll upload the new tune to forum once I have it dialed in a bit better. Now that it's getting colder here I've had an opportunity to dial in cold start and warm-up more.