1994 Civic with 1.6L factory everything. Bought from old folks who had it since new and garaged most all it's life. Issue of passenger side front floorboard water buildup which I believe led to ECM malfunction. First issue was engine light, followed by fuel pump becoming less and less dependable, then blower motor stopped. Also, radio burned out several months ago... just malfunctioned and I could smell electrical smoke until I turned it off.

Fuel pump would charge up at first, but car would start, then die. At some point, the car would start and run fine. Later, I'd have to turn on ignition, then off, then on, until I could hear the fuel pump charge. Eventually, I almost didn't get the car to start and run for a drive home from work. The rain stopped for a long period and I went to just give the car a try... since then, it's started right up and run fine, but blower motor not working but very rarely (it works normally at sparse times) and engine code shows O2 sensor, but mechanic told me he didn't suggest doing that because it seems like another type issue.

Another local mechanic suggested unplugging ECM and spraying into the harnesses with starting fluid to disperse any remaining water, then coating around the harnesses with dielectric grease to keep any more water from working it's way in. I did that yesterday, and there is no change in anything. The blower motor still doesn't work properly and engine light still on.

Any suggestions would be greatly appreciated before I order a new ECM, which is my last resort.

 

If the car has a sunroof, the front right corner drain runs down the passenger A pillar and through the fender support, however the connection to the exterior of the car is just about right behind the ECU. I'm betting your drain hose has been leaking down there. Pull the ECU out and open the case - look for bad electrolytic capacitors on the board. You can try replacing them if the leaking electrolyte hasn't destroyed the surrounding traces. If that's the case, source another ECU and replace it, and find the source of the water and repair that as well.

 

Opening the ecu up and looking for any obvious issues isnt a bad place to start. But for evey ten computers i replace only one maybe two gave tale tell signs of something wrong. I would choose one of your issues, do the diag and see if it leads you back to the ecu. I would start with the blower motor. Seeing you should only need a wiring diagram and a test light to trouble shoot it. The fuel pump issue your having might require a tad bit more diagnostic equipment ie fuel pressure tester, amp meter volume tester. Stuff like that.

 

Thanks for the replies. I got the things together to start checking out the blower issue and saw there was some rust on the bottom of it. Figured the easiest first thing to do was to give it the "tap" test with a wrench, and of course, that made it start up. Ordered a new one and installed it yesterday. Now, it blows harder than ever, but apparently the water is coming into that location. The old fan even had pine needles IN THE BLOWER. Is it normal for debris to work it's way down into it?

Main thing I have to do now is to locate exactly where the water intrusion is. No rain for a month, so not sure how to test that. The car is an EX and has the sunroof. If there's a way I can "try" to make it leak, I can try that or else I will wait for the next really good rain and get in there to locate the problem as best I can. Just one step at a time. The fuel pump has worked perfectly ever since everything has been really dry, so wet weather definitely has something to do with that malfunction I would think.

Any ideas I can try in the meantime?

 

Yes it's common for the blower to get leaves and needles. These cars do not have a cabin filter to stop it from pulling in from the cowl area.

 

Run a hose over the roof of the car. The sunroof drains are in each of the 4 corners, and the drain tube runs down the corresponding pillar. If that doesn't show you where the water is coming from, run some water down into your cowl intake at the bottom of the windshield - I wouldn't do a wide-open garden hose, as the cowl won't see that amount of water. Lastly, you can try popping the hood and running the hose on the seams around where the hood hinges are. Honda issued a Technical Service Bulletin (92-050 - Google it and you'll find a copy) for fixing the leaking seams.

 

Thanks TomCat. Seemed strange when I saw it, but at least I know it's nothing unusual.

 

Getting the right ecm relies on knowing what engine you have.

 

It's the 1.6, but now that I know the real issue is water, I will fix that first. ECM is a last resort and the fuel pump is working as it should since the rain stopped and been dry for a long time. I can now see at the base of the windshield where water can easily get to the seals, so I have to reseal first of all.

Only real question I have now is the engine light. Can the code be reset as easily as it is on a Chevy truck?