Hondata

I have a 1996 civic ex with a hondata s300. I installed the unit about a week ago and it ran fine. Now when I turn the car on I get a solid red light on the s300 for about 5 min then the fuel pump kicks on and I can start the car. If I drive the car for an hour or so and turn it off the car will then turn back on. The longer the car sits the longer it takes to start back up.

It may be a problem with the ECU itself. If you remove the s300 form the ECU, does it do the same thing?

yes it does the same thing.

It is not the s300 then. You may want to try replacing the main capacitor in the ECU (the large one). IF that does not resolve the problem, then you will need to find a different ECU to install the s300 into.

The big one as in the one that stands out from the rest

yes

Hey guys, I have the same issue as the OP. I bought a v1 Hondata s300 installed in a p28 from a friend. I also have my original P61 with a s100 installed. When the car is cold or the ECU, it takes an average of 20 mins for the red light, visible through the USB port, to go green. At that moment, I can hear the fuel pump prime (fuel pressure guage shoots up to 38 psi) and I'm able to start the car. After the car is warmed up, and I drive it around for a little while, the green light comes on seconds after I turn the ignition on. If I let the car sit for a while, I'll have to wait longer for red light to go green...it seems the longer the car is off, the longer it takes for the light to turn green. If I swap out the S300 equipped ECU for my P61 w/ the S100, it starts up every time, even after letting the car sleep for days!
I've replaced and added extra grounds to and from the chassis. I've clean, added and secure the grounds on the thermostat housing. I have no other electrical issues with the car nor do I have lit engine check light. After reading this thread...I'm now thinking it may be a faulty capacitor that is not holding it's charge? Is that possible? I'm at my wits end on this one and is hoping that my friend would nullify the deal, I give him back the ECU and he give me back my money.
I think I've reached the end of the Internet :/

Try replacing the capacitor, or swap the s300 to a different ECU.

Well, I had the capacitor replaced and all the pins for sockets resoldered...but I'm still having the same issue (I have to wait over 20 mins for the solid red light on the S300 to go green after the cars is off for any length of time). My only option now is to do as spunkster suggested and get a new ECU socketed for the S300. I'll update this thread if it turned out to be ECU.

Note: prior to replacing th capacitor, I took my ECU over to my friend house and connected it to his Integra, a 95 RS. When I first turned the key, there was a 2 second delay before I got the green light.
After about 20 mins being plugged in, I removed it and brought it back home and reconnected to my DB2, and to my surprise, the damn thing went green as soon turned the key on. It seemed like the capacitor got charged up while it was plugged to my friend's car.