Hondata

The conversion harness would be my first guess. An easy way to check the conversion harness would be to remove it from the car and test the resistances on each end of the harness with your multimeter to rule that out.

I noticed the owner of the local dyno shop didn't have a conversion harness on his obdi ecu in an obdii civic. I asked him about it and he said all conversion harnesses are cheap and eventually short out. He had ordered his ecu with the obdi conversion built in.

still waiting on a response from spunkster.

ohmed out the harness and everything ohms good, although there is one wire that confuses me a little in the harness.

On the OBDI side of the harness there is a wire that goes to A7 (FLR1) and then it splits into 2 wires and goes to the OBDII side A15/A16 (FLR). A16 is unoccupied according to my wiring diagram.

According to the diagrams I have, the harness is suppose to take A15 from the OBDII side and turn it in to A7/A8 on the OBDI side.

I ohmed the ECU's A7 and A8 to eachother and they both seem to goto the same point anyway, so it shouldn't be a big issue, but by reversing the wiring scheme for that might improve it in some way, but I don't see the point of doing that right now.

used multimeter to test power and ground/fuel/ignition system voltages under non-running conditions.

A1-3, A5 = battery voltage
A7 = battery voltage
A21 = 11.83V
A23 = 0V ohms 0.3 to ground
A24 = same as A23
A25 = battery voltage
A26 = 0V ohms 43 to ground
B1 = battery voltage
B2 = same as A26
D1 = battery voltage

here's the same checks when the car is in running condition.

A1-3, A5 = battery voltage
A7 = battery voltage
A21 = 11.83V
A23 = 0V ohms 6 to ground
A24 = same as A23
A25 = battery voltage
A26 = 0V ohms 60 to ground
B1 = battery voltage
B2 = same as A26
D1 = battery voltage

Has the car ever run properly after converting it to manual?

car ran perfectly up untill a few months ago.

and what happened then, what changed?

I went to another state for training and the clutch system went out, it took about 2-3 weeks before I could get the proper parts for it, and by then I had to have it towed back to my home state, so basicly the car sat for nearly a month and then it wouldn't start, I inspected the starting system and resoldered some wires just in case that was the issue and it just started up again one day.

I'm starting to think possibly the ECU might have a cold solder joint or somthing. Last night I started the car and it ran for a minute, then I took it out. I brought the ECU and harness inside, I was checking it for about 1-2 hours and when I brought it outside and reinstalled it, it wouldn't start up again. I went to the store for about an hour and then it started up when I got back.

When the car wont start, the light in the USB port is constantly red and I get a CEL, but I don't get an error code.

I had similar problems on my S200 in a P28.

Turns out it was the ECU. The socketing job left much to be desired.
The motor was actually shutting off on me randomly though. I could not communicate with the computer / Hondata with the motor off and ignition on either.

I would bet it is the ECU.

ok, I checked all of the solder points on the ECU and they all looked ok, I resoldered a few just incase.

Durring my inspection I looked for leaky capacitors and found C21 and C24 were both leaking, I don't have a schematic of the P28 ECU so I'm not exactly sure what these 2 capacitors do for the ECU, but I'm sure it's not a good thing that they are leaking.

Is it possible to send this off to Hondata and have the ECU run on a diagnostics and bad components replaced? here's some pictures of the capacitors.

Once the acid in the capacitors leak out, they damage the board. You will need to just get another ecu and have it socketed for your Hondata system.

in regards to getting a new ECU and installing my current Hondata into it, I've found a potential ECU, but here's my issue, some of the parts are still soldered into the current ECU, am I going to have to desolder the tracks and mail them off with the S300 or can I just get the new ECU, remove the S300 and mail it off together?

If all you are doing is having an ecu socketed, you do not send the s300, and you do not send any components. All we need is the ecu, the socketing form, and the cashier's check or money order.

so mail it off with the form and cashiers check, a few days later I get the ECU back ready for my S300 to go back in?

yes