1992 Honda Civic LX (AT)
My engine fails to start. The starter motor cranks and the fan turns on (the one beside the radiator, not the one on it) when the key is in the ON position. The check engine light, along with the battery and oil lights come on and stay on when key is in ON position.

I tested the voltage between the MAP sensor (yellow green wire) and ground (scratched paint off body behind sensor with lead and used bare metal), the meter read 0.33 volts.
I spoke with my mechanic who has worked on this car since it was born and he told me, knowing my car that he believes it is the ignition coil (I was not able to show him the pictures since he now lives an hour away). He suggested a test involving a test light and another person turning the key (both of which I presently lack).
Is that voltage reading (from the K-test) a clear indicator that the ECU is all together bad and MUST be replaced for the car to run?
If so, the # on my ECU is 37820-P06-A50-741, I located one that is 37820-P06-A52-741 (from a 1995), will this work in my 1992 civic?

I plan to take the distributor cap off tonight and check to see if the resistance is within spec for the ignition coil (have OEM shop manual). If resistance measures out of spec, is this a clear indication the coil must be replaced?

I am unable to tell if the fuel pump comes on when I turn the key to ON since my car is located on a busy street and the fan comes on as well. I may also try a test suggested this forum (txgreasemonkey, I really appreciate all of your advice, it has been very helpful) where I connect 5 and 7 leads in the MAIN RELAY to activate the fuel pump when the street noise is less this evening.

To summarize my questions:

Is the voltage reading (0.33) a clear indicator that the ECU is all together bad and MUST be replaced for the car to run?

May I replace the few components in the ECU / ECM that appear damaged or do I have to buy a refurb?

Any other suggestions?

Yes, the K-Test correctly indicated that your ECM is "toast." Like so many other Civic ECMs, your electrolytic capacitor leaked. If you are lucky, you may be able to replace the capacitor. However, your best option will likely be to replace the ECM with an exact part no. match. I recommend that you buy a remanufactured ECM with a lifetime warranty--check with O'Reilly Auto Parts.

I place little faith in bench testing coils--I've seen too many that test okay that don't work. I believe that your failed ECM is why your Civic won't start, not the coil. If you replace the ECM, the main relay and fuel pump should work fine.

Quote:

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Originally Posted by txgreasemonkey

Yes, the K-Test correctly indicated that your ECM is "toast." Like so many other Civic ECMs, your electrolytic capacitor leaked. If you are lucky, you may be able to replace the capacitor.

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So I (accidentally) removed the back cover to take a closer look at the capacitor numbers in hope of ordering a $1 part and fixing (instead of $275) as a result of reading of people doing this with their ICU's and WOW! I had no idea capacitors could be so violent!
You weren't kidding when you said "toast" - this thing is FRIED and let out a strong smell of burnt electronics as soon as I removed the cover (a smell I noticed the evening my engine died while driving down the road, coincidentally also the evening the remnants the FL Hurricane swept through and blacked out a good portion of Pittsburgh, while I was waiting in my car for a tow, the wind knocked out a transformer in front of me sending off a beautiful blue firework).
I found one on eBay for ~$100 I'm going to try.

How important is this lifetime warranty thing? Is the capacitor going to explode again?
I read here this is pretty rare. I've read in previous posts that this a known design flaw but is it possible something else going on that may have caused the capacitor to blow?

Your ECM is not just toast, but burnt toast! A lifetime warranty is only significant if you want to keep your car for years, like me.

I had the same issue on my 92 DX (195K) just last week. My thanks as always to txgreasemonkey for providing troubleshooting advice that helped me identify my problem.

Your pictures look exactly the same as mine. I took off the blown cap and cleaned up the board and it had blew a nice hole in the board... not worth trying to repair. I ended up finding one at a salvage yard for $125 after Oreilly and Advance Auto didn't have them readily available. After I picked it up, my wife was driving home and I took it apart to look and compare it to my old ECU, and realized that it had been chipped at some point (with a kit similar to what you'd find at phearable.net and someone had subsequently removed the modification, and they were also kind enough to cut capacitor C30 out when removing the modification. It might have still worked without it, but I took no chances and desoldered one from my bad board and added it to the salvage board before I hooked it up and it worked great. So when you get yours, I'd recommend checking it closely to make sure it hasn't been modified.

The ECU arrived in the mail last week (~$100 ebay), I opened it up and carefully inspected and compared it to my burnt ECU, everything looked good and all of the numbers matched. The car started up as soon as I plugged in the ECU. :) I drove it about 5 miles several days later, left it sit 4 hours and then drove another 5 miles, no problems (did not turn on vent fan or radio since I wanted to listen to car). Yesterday, I drove the car about 7 miles, no problems. It sat in the sun for ~2 hours and would not start when I returned to it. :(
I heard the fuel pump turn on when I first turned the key to the ON position. After about 10 minutes of messing with my GPS, I turned the key to start and it was just like before - the starter motor cranked away but the engine did not start. I removed the key, waited a few minutes and tried again with the same result. This continued for about 30 minutes, I noticed when I listened that the fuel pump did not always come on. After about 20 mintues, the sun was covered by a cloud. After 30 minutes, I made a call on my cell phone, as it was ringing, I turned the key and the motor started.
I turned on the radio (stock honda tape deck) as I was returning home and the sound was cutting off and on (to all speakers), just the sound and not the power as evidenced by the display remaining on. I've had problems with the front right speaker in the past and this was different. I turned off the radio. I noticed a smell that reminded me of the burnt electronics smell when my ECU fried the first time around and my heart sank. The car got me home.
3 hours later it started on first attempt and drove 15 miles (used headlights and vent fan, no A/C or radio). After 3 hours, it started on first attempt and drove 15 miles home. I noticed the brightness of headlights were fluctuating (not a flickering) from very dim to normal on the drive home. My instrument panel had been flickering on and off before I replaced the ECU, now it was on and dimmed appropriately with the dimmer switch.
I'm afraid to check the ECU again, please don't be burnt! :(
My feeling is that it may be related to a rusty or loose ground wire (I live in western PA where we are famous for car rust due to the large volume of salt we use on our roads in the winter). Other than that, the ICU comes to mind.
I would appreciate any guidance or ideas on where to begin or what to try next. :confused:

I need a p28, are any of the other numbers compatible with this 94 civic vtec 1.6 auto

josho87, my advice is to get an exact part no. match. Anything else is too risky, unless you get a warranty.

If you PM me with the complete vehicle description, VIN, etc, I can help locate a module for you.
Or you can see the website in my profile.