I have been having issues with my 1995 civic coupe it won’t start / send power to the fuel pump unless the ECU has been in my house and warm. If I leave the ECU out side in the car it won’t start at all. I have two ECUs I have tried and it’s the same thing every time. Not sure if it’s the ECU or somthing else. Please let me know what you guys think. I have changed the fuel pump, fuel filter and two different relays.

(it’s been about 45 degrees)

 

Well , I had the same issue on my stock obd2b ecu , went to replace pretty much everything (internal of the ecu) but it turned out it was a part that could not be changed sadly, so I kept my ecu warm as well , until I went to obd1, never did manage to fix it , thankfully my obd1 ecus were in good shape.
But its weird that 2 other ecus doing the same.
I would say for starters try all 3 ecus in a car that is known to work , just to rule out the ecus (either working or not)
that should be the first step.

You can also check the wiring , meassure it with a multimeter and move it around to see if it breaks connection and whatnot , everything in me says that there is no way all 3 ecus are bad.

 

Yeah I’ve checked power etc it’s such a weird issue. I’m gonna try one more ECU. It’s odd because it’s like a delay on the first start to power to the fuel pump prime.

 

Your issue is likely capacitor failure for the main power/fuel pump circuit pathways... the sooner you repair them, the better chance you have of not further damaging the ECU board/traces from the leaking electrolytic fluid. These types of failures are SUPER COMMON right now because these ECU's are all now 25-35 years old. I have a whole pile of damaged ones... you only have two.

 

Is this a pretty easy fix?
or just newer ECU

 

If you are proficient at soldering... you can fix it. The longer the problem exists, the less of a chance you can actually fix it. OBD-2 ECU's are more difficult to fix and the parts may be discontinued. There are multiple sources for the capacitors or you can send the ECU out for repair by a professional.

 

Sounds good thanks for the info. I will look into this. Thanks again.