My S300 keeps disconnecting!

civiclova · Post by **civiclova** » Wed Mar 12, 2008 6:15 pm

Hi,
i have a b16 engined 99 civic hatch and am having problems with my s300 that keeps disconnecting (going from online to offline after 5 secs of USB USB connection! while back i didnt have this problem and it all started when i installed my electric cutout and s300 disconnects ONLY when i hit the rev limiter when the cutout is fully open! then it became worse when i had to upgrade my stock ignition system to M&W Pro-10 and crane coil and S300 just stays online for 5 secs then disconnects! here is what i did/followed from hondata tech/honda-tech pros:

1- installed resistor type spark plug
2- checked wiring that is all clean and all heat shrinked to prevent any shortage
3- removed my HID kit cause it might be causing all this! now have the stock bulbs on
4- fit an MSD noise filter which is nothing but 12v capacitor at the ignition box (http://www.jegs.com/i/MSD/121/8830/10002/-1 )
5- used a shorter USB cable
6- installed latest S300 version which is 1-3-3 and checked for driver update and software says my driver is up to date!

my S300 still disconnects and thats with the laptop battery on!

any sollutions for my problem here? i dont want to go for another aftermarket box

Post by **Spunkster** » Thu Mar 13, 2008 9:46 am

What you have described is most likely ignition related. Try using just a stock distributor and coil.

civiclova · Post by **civiclova** » Thu Mar 13, 2008 11:43 am

Spunkster wrote:What you have described is most likely ignition related. Try using just a stock distributor and coil.

am about to run some high boost and prefer to use the gap the plugs come in and use an ignition system instead of gapping the plugs down! i tried it once with the stock ignition system and didnt get good results like i did with the ignition system

i'll try a few things out and see how it goes!

civiclova · Post by **civiclova** » Thu Mar 13, 2008 8:49 pm

here are a few things i have done/checked:

1- used DC power supply to match my latop ground to car ground (no results)
2- disconnected my electric cutout to prevent its noise (nothing)
3- used resistor type plug
4- used insulator tape around the USB port and even taped the front ecu case too
5- put some fabric under the ecu case and above it to prevent any shortage with any other wires
6-put MSD noise filter at the M&W ignition box(which is a capacitor)
7-checked current of USB with battery - terminal and get 0 to 0.001mA
8-checked voltage of USB with battery + terminal and getting 16-26mV (which isnt good!)
9- checked CPU usage and it goes to 100% suddenly when i try to datalog when engine running at idle
10-upgraded to S300 version 1-3-4
11-tried different USB ports on my laptop
12-checked driver (ok)
13-USB check (ok)
14-checked USB showing on my hardware...it states that device is working properly which is good (thats with the USB port connected an key on ignition)
15-used different lengths of USB cables (nothing)

noticed my rpm needle sometimes bounces and the only gauge that goes off then on suddenly when driving (does a sweep test as if it was switched OFF/ON) is my electrical oil pressure gauge! the oil press sender unit is the closest sensor to the ignition coil!

am out of ideas here, so what else i should try? am starting to think there is no way out of it! the only way i kinda tuned my car yesterday was to enable the internal datalogging, but its starting to be headache for me since i have to keep downloading from the ECU,save file and load back again just to see my readings!

any help guys?

Post by **Hondata** » Fri Mar 14, 2008 8:53 am

Put the ignition system 100% back to stock, and then make one change at a time to determine the problem.

SOHC_STUDENT · Post by **SOHC_STUDENT** » Tue Apr 01, 2008 7:00 am

Hey, I was having this same problem. It turned out to be carbon fouled plugs...

civiclova · Post by **civiclova** » Tue Apr 01, 2008 6:32 pm

SOHC_STUDENT wrote:Hey, I was having this same problem. It turned out to be carbon fouled plugs...

can you elaborate more about this? are you saying your fouled spark plugs cause the hondata disconnections? are you running kinda rich?

SOHC_STUDENT · Post by **SOHC_STUDENT** » Wed Apr 02, 2008 6:14 am

civiclova wrote:
SOHC_STUDENT wrote:Hey, I was having this same problem. It turned out to be carbon fouled plugs...
can you elaborate more about this? are you saying your fouled spark plugs cause the hondata disconnections? are you running kinda rich?

I run ITBs and they idle around 10 AF. I was experiencing the datalogging cutting out while idling, trying to lean out the idle. The engine started to stumble shortly thereafter and then didn't want to start. The plugs were black when I pulled them. I cleaned them off and the car started so I took it out on the road and opened the throttle to heat things up and clean off the carbon deposits. After that datalogging seems to work fine.