Hondata

2002 Acura RSX Type S
2008-503173
37820-PRB-A05
V3.3
Car has Turbonetics t3 .57 turbo, RC 550 Injectors, Buddy Club turbo back exhaust
Will upload datalog in few.

Problem arose when during wot tuning. I saw older threads but didn't know if there was a new way to fix this issue. We changed plugs out, tried 2 different laptops and different cables.

Thanks for any info.

Are you using resitor or non-resistor type spark plugs?

Yes, they are resistor the plugs are NGK BKR9EIX Iridium IX.

You need to determine why your battery voltage is dropping to 12.9V just before it disconnects. It starts at 13.7V

I did several runs I didn't save but I didn't notice it drop below 13.x but still had a d/c. I think I was rolling up a window or something bc I was getting on the interstate.

Hi. Im having same kind of issue.

The car is ek4 1999 k20a2.
Its boosted now but did same thing when it was na.

So the problem is that everytime it starts to make real power on boost
usb disconnects. On part throttle i may drive for hours and its logging normally.
When car was na it did the same thing but not that often.

Parts i changed:
-new kpro 3 (old is working fine in other car, i have tried 3 different kpros)
-new engine harness
-new battery
-new grounds/ added more grounds
-new sensors (tps, crank, 4 bar map,)
-new coils
-new spark plugs (resistor)
-new relay in hybrid racing swap harness
-new/different usb cables

Laptop is working fine in other car.
Even its disconnecting usb, on board datalogging is working fine.

My charge light didnt work so i changed another alternator and after that charge light
has been working. On dyno it gave daughter board (low battery error code)
even the battery was charged (+14v)
I changed coils and error code goes away.

I noticed that voltage is dropping to 13,2-13,3 on boost, i dont know why.
Battery is in stock location and there is no big stereo system.

Any idea what is causing this?

Thanks.

What is the part number of the spark plugs?

"Added more grounds" is a bad idea. You only need the standard grounds; any extra just create ground loops and extra noise.

The hybrid swap harness has very undersized wiring for the main, fuel pump and o2 relays (at least the one I got this year did), which could explain the voltage drop.

Na plugs: ngk izfr6k 11

Turbo plugs: brisk racing dor10 ir

Yes the swap harness is probably next ill have to re-do.

Grounds are changed for your recommendations. Use to have little bit different. Didnt help.

The brisk racing plugs claim to be resistor, but does not specific the value. I would switch to a denso or NGK.

I changed swap wiring to k-tuned and engine is now euro spec k20z4 NA.
It still doing the same thing now and then (disconnect ecu from laptop). Usually 2-3 times when ill first time connect laptop to the ecu.
No problem after that on wot. It gave daughter board error 2 times on the dyno. Uploaded calibration and worked fine after that.

Is the K-Tuned harness any better? The daughter board error is caused by a large voltage drop to the ECU, especially when cranking. It can be from a dead battery, but often is the main relay wiring.

Hondata wrote:Is the K-Tuned harness any better? The daughter board error is caused by a large voltage drop to the ECU, especially when cranking. It can be from a dead battery, but often is the main relay wiring.

Ok thanks for that.

You may try a quality USB cable with built in ferrite beads, and/or add more beads to both ends of the cable. I had disconnect issues and went through the whole list of 'fixes', but nothing really worked. Added a few extra beads to the USB (pics about 1/2 way down) and the issue stopped immediately and I haven't had a disconnect since.

viewtopic.php?f=12&p=35564

I will try that. Thanks.

Random information..... Another issue tha can cause disconnect can be Spark plug GAP... Especially on boosted applications. To big of a gap can cause spark blowout which will cause a surge that will force disconnect Kmanager.... I had it happpen all the time on WOT... lessened the Gap... no Blow out... No Disconnect!