So here's the deal. A couple weeks ago my civic just shut off and would not start again. I went through and gave it a full tune-up. (spark plugs, wires, filters, cap & rotor) I ended up solving the problem when I replaced the Ignition Control Module and Coil. I also had some bad gas that had water that was freezing up on me. All the problems seemed to be solved with the ICM, Coil, some new gas and some Heet. So I ended up taking the car on a trip (for the holidays). Everything was going fine, ran like a top all the way there, and most of the way back. I was coming down this hill and all of the sudden it just started lurching. (my foot wasn't on the gas, as I was going down a hill). I stopped at a gas station not even a quarter mile away. When I went to start up the car it started right up, then just quit. I tried to start it again and it started up fine and ran. Going down the road, the rest of the way home (about 40 miles), it occasionally lurched. I brought it home and left it sit overnight. When I tried to start it the next morning, it would fire up fine and run, then just shut off. It did this about 6 times. Finally it stayed running. I took it straight to the mechanic. He hooked up it up to the diagnostics, and the car would not repeat what it had done. He couldn't find the problem. It ran fine all the way home from the mechanics, I shut it off and started it a couple times in between the mechanics and home. The mechanic also said that it did not shut off the entire day that he had it. I do have a check engine light when I before I start it, and it does go out. I also have fuel pump. I checked the main relay when I was searching for the problem last time (coil and ICM), and it clicked twice before the car started. Could the main relay be intermittently failing? Or is there something else? Any help would be great!

I believe the owners of older Hondas (i.e. at least 10 years old) should bite-the-bullet and just replace the ICM, coil, distributor housing, main relay, and ECM, if like-new reliability and performance is important to them. If these cars are their primary means of getting to work, then this advice is even more relevant.

I am getting ready to move, and am trying to keep a budget, basically get the car running good again, but I don't want to replace all of the above if that is at all possible. I'm trying to narrow it down a bit, and maybe replace all the rest at a later date. What does it most sound like to you, a main relay?

Is it possible for a main relay to intermittently fail?

Try resoldering the old main relay and see if that solves the problem; otherwise, just replace it. They run around $45. It could be that when the main relay heats up cold solder joints cause it to fail.

The car runs better when it's warm than when it's cold. When it's cold it just wants to keep shutting off after I start it. When it's warm it barely does it.

Is there any way to test the main relay?

Standard bench testing procedures do not test for intermittent cold solder joint failure, which separate and fail when the relay heats up. You can likely find the standard bench testing procedure on the internet. The problem stems from poor PCB soldering.

Is there any way to test for a bad ECM? And if it was a sensor in the distributor wouldn't I have a CEL?

I developed the K-Test to test for a failing ECM. It's an overall test of the ECM to function like a power transistor. However, it does not test all aspects of the computer. It also does not test subtle problems that can be caused by oxidation on the connector or pins to the ECM--problems that definitely can affect performance. Intermittent problems are notoriously difficult to solve, at times. That's why it's important to establish a "known-good baseline."

I had a Civic distributor that was failing miserably (in fact, destroying itself) and the CEL never came on. Simply amazing.

What do you mean by "known-good baseline"?

Components that are known to be good. You are eliminating as many potential problem areas as possible. Examples are ensuring the battery is fully charged, under-dash and under-hood fuses are okay, ICM is good, coil is fine, etc. Through process of elimination, you focus in on the cause of the problem.

Okay well, the coil and ICM are brand new, cap & rotor are good. I don't know about the ECM, distributor housing, or the main relay. I noticed the main relays are fairly decent priced, so I may go get one tomorrow. If that is not the problem I'll check back with you. Thanks for the help.

ICMs, coils, main relays, and distributor housings are the most common electrical components to go on Hondas. Main relay problems usually show up during the summer, where the car starts okay in the morning, when temperatures are cool, and fails later in the day, when temperatures go up. I recommend drilling ventilation holes in the cover, to help prevent heat buildup.

I just went out and started the car. Its been sitting 3 hrs. It started fine, then shut off. I started it back up, and it almost died, then picked back up before it died. This is new it hasn't done this before. Then it continued to run fine. Does that help narrow it down at all?

It really doesn't sound like a bad main relay. However, it could be if it's really messed up. Your's just would not be the "classic" symptoms most people look for.

. Clean main ECM ground on the thermostat housing. Look for a 3-wire brass connector--remove and clean with abrasive cloth. This is a must!

. Disconnect negative battery cable for 10 seconds, or remove the Backup Fuse in the under-hood fuse box for 10 seconds, to reset the ECM. This is a must!

. Perform K-Test on the ECM. This is a must! Tell me what voltage you record at various times, especially after the engine dies. ECMs that are experiencing intermittent failure show 5 volts, when everything is okay, and .3 volts, when problems arise.

. Using a mechanic's stethoscope or large handle screwdriver, can you hear each fuel injector click, when the engine is running?

. Check vacuum hose connections, particularly to the MAP Sensor.

Okay so I ended up taking the main relay out. When I went to do so, I just barely wiggled the relay (before taking it out) and then the car wouldn't even start after I did this. And this is like 10 mintues after it was just running fine. I then continued taking it out. When I got it out, I noticed that it had been mauled up some, looked like someone had been into the insides of it. So I took it apart. Someone has already resaudered it and it looked horrible. Definitely just globbed on there. There was one that is definitely cracked around the bottom rim of the sauter joint. I tried to get a new one, but it's on order until Tuesday. Does it sound more like the main relay or am I still barking up the wrong tree?

I think you nailed it! You definitely need to replace the main relay. Again, most problems Hondas have are related to issue with ICMs, coils, main relays, ECMs, and distributor housings.

All right. I just went and put the main relay back on and it still doesn't start. I am getting all three clicks though, that doesn't rule it out though right?

No. At this point, the only thing you can do is wait until you install the new main relay on Tuesday, or try resoldering the relay yourself for something to do. I would wait and do the job right. It's part of establishing a known-good baseline.