Hondata

KManager 4.1.4.0
02-04 RSX Type S PRB ECU
NA K24/K20 swapped 2004 S2000

Trying to track down why I'm getting a bunch of knock and it looks to be linked to cam angle changes. Locking my cams to 0 produces little to no knock and stepping up the angle amplifies my knock count. Looking through my logs, I see a lot of bouncing around of my cam angle even though the cam command holds steady.

Just wanting to know if this much sensor is fluctuation normal...

Holding the cam at 0 reduces the dynamic compression, since the intake valve closes late, which is why you're probably getting less knock.
The fluctuating VTC is from low oil pressure, clogged VTC filter screen, bad VTC solenoid or a bad VTC cam gear. From people who have had similar problems it usually is the solenoid or camgear which is the problem. Of course check the wiring and grounds too.

Yeah, been having the VTC issue for a while and have replaced and cleaned all the things you listed.

I think what I am looking at here is an electrical issue. My battery voltage and ELD is very jumpy. Could explain why multiple sensors are also jumping around.

Been poking around and found someone with the same issue. They noticed that the ELD and BAT were much more stable before the O2 relay kicked on. I saw the same thing in my logs. Just now disconnected the relay and did some data logging. My voltage still jumps around, but not nearly as much. ELD is far more steady, but not quite flat like I've seen that it should be. With VTC enabled, knock was much lower that I would normally see.

S2000s don't have the O2 relay setup like a K Series, so I had to wire in my own

I followed the wiring diagram shown here. https://www.hondata.com/?_route_=tech-k20-swap-wiring

There is obviously something else left to figure out however. Having my O2 relay wired up like the diagram shows, doesn't seem to be the root cause, but it's interesting that it would have that large of an effect on my ELD.

I suspect this could be related to the dual mode charging that is happening with my ECU. I know Hondata has stated that this is not enabled in K Series ECUs, but it is in mine and maybe there is something different with my engine harness. With ELD disabled in KPro, I do not see the dual charging behavior. I will see what happens when I clip the ALTC wire...

It is not the alternator control. If you're seeing the battery voltage change when the o2 sensor heater is active, then it is the wiring.

Thanks for your patience/help on this and my recent barrage of questions. Not to but like 5 years ago, I had no idea how a motor even worked haha. Fun stuff and because race car.

Questions
- Am I just looking at noise in the datalogs? I ask because I'm not seeing rapid voltage, eld and cam fluctuations in most other K-Pro datalogs I've seen. Sorry, just no experience with this to determine otherwise. This guys K24A2 was having the same issue. http://www.hondata.com/forum/viewtopic. ... &hilit=VTC

- Is the O2 heater relay supposed to be on all the time when the ignition is on? Didn't think that's how it worked. My pin E8 has connectivity to ground right when I turn the ignition on and from seeing my wavy ELD during my entire drive, it doesn't ever seem to turn off.


Not totally necessary to read through this, but here is what I found out last night.

- With my O2 relay disconnected
- BAT rapidly fluctuates between an average of 13.8 and 13.9
- ELD at the same rate +/- 0.8 amps
- Cams, same rate +/- 1 degree

- With O2 relay connected
- BAT from 13.9 to 13.7
- ELD +/- 5 amps
- Cams +/- 3 degrees and some times up to 7

- The lower angle I lock my cams, the lesser the fluctuation I get. Hoping this is the reason I get less knock.
- With the engine off and ignition on, I still get rapid .1v changes
- Disconnecting the ALTC wire had no effect other than to keep my voltage near 14v with the engine running
- Disconnecting my alternator all together had no effect on everything above. Other than dropping my voltage to 12v.

A few things I will try next will be to switch out my remaining sensors that are from other k-series non 02-04 RSX Type S sensors. What's left is a TSX crank position sensor and my cam positions sensors are from my 07 Si. Same part # for exhaust cam position sensor, but different on the intake side. Thought this could be it so I swapped my intake with exhaust and vice versa. No change, but for peace of mine, I might just get 2 new ones.

Have you read the info at: http://www.k20a.org/forum/showthread.php?t=83896

The problem is from either a bad ground path or bad power supply. Everything you describe is a symptom (ELD, cam angle fluctuation, battery voltage fluctuation etc) but not the problem. When the o2 heater is on the current draw is higher so the problem gets worse. Ignore the symptoms and look for the cause.

Thanks, that makes sense to me.

One thing to add however, is that there are times when my fluctuating sensor values smooth out or get worse based on RPM and load. Also gets worse when the motor is cold and a bit better when fully warm. My motor mounts are fairly solid so dono if vibration might have an effect on power supply.