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Hey peeps, so I bought an 03 civic 1.7L non v-tech. Had it for a month now, car was doing great, then one day I go out to start it and no go. I changed the map sensor, new fuel pump relay. Did nothing, so I was told it was the ecu, went to parts shop and got a used ecu for the same exact car. Even the ecu numbers were the same. So I put it in, called a locksmith and got my two keys, the vin number attached to the ecu. Also had the blinking green key on dash when installed ecu. So problem was fixed, to I start the car, let her run for about 5 mins at idol while I finished getting ready for work. Got in the car, drove maybe 1/4 mile the car shut off on me, so I rolled into a parking lot and parked it. Tried to start the car and nothing. It will crank, sometimes it almost fires, and that key icon is blinking when I try turning her over. Any ideas?

 
Rep Power: 222

Checked timing?

 
Rep Power: 367

check if alternator bolts are loose.
that fries ecus

 
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Really? I do have one that is broken going to replace with through bolt.

 
Rep Power: 367

loose alternator causes voltage/current fluctuations that electronics hate
it's common on these cars

 
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Ok just got the car home and looked under the hood, sure enough alternator bolt is sticking out. And in order to do anything I知 going to have to take off power steering, then exhaust manifold in order to drill out hole for new bolt. Can I through bolt it?

 
Rep Power: 119

Maybe. Is it the top or bottom bolt that is broken? My 05's top alternator mounting bolt stripped out while I was driving about 8 years ago, so I ended up just getting a new/used alternator bracket from a junkyard instead of trying to fix my bracket. Whatever you do, it is critical that it's solid. The alternator grounds through the bracket and bolts and if it loses its ground it will try to ground through the green 4 pin connector that goes to the ECU and could easily fry it. I added a ground wire from my alternator to the chassis for extra safety. That way if the alternator breaks loose again it doesn't lose its ground and fry the ECU or anything else.

 
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Yea I looked under there and noticed the top bolt hanging out. So I pushed it back in and tried to thread it but it痴 either someone put the wrong bolt in or it broke at the threads? I read that it痴 possible for the alternater can go bad as well and still work, but would continue to burn ecu. So I知 going to get used bracket and alternater. Replace those and probably the ecu as well (again). Get the locksmith out again and start over.

 
Rep Power: 224

Threads in the bracket are probably stripped, it's just aluminum. Don't waste money replacing things that you don't know are bad, I would just go for the bracket for now. You can unbolt the power steering pump, remove the reservoir from it's bracket, then pull the whole thing out of your way so you can get to the alternator. Alternator bracket is also used for the engine mount on that side so you'll have to undo that as well.

 
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Yea so definitely was stripped, not only the bracket but the bolt as well. So I just drilled it out and threw in a through bolt, lock washer and nut. Holding good, had the tech come out again to rescan ecu and it was a no go. I must have fried it. Gotta get another one then call the tech again. I let u guys know how it goes

 
Rep Power: 224

Did you check the lower alternator bolts too? One bolt with a wingnut to tighten the belt (this also has a nut to tighten once the belt is tight), then another bolt from a bracket to the block.

 
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thanks guys, all is good! So glad, who knew an alternator can do hundreds in damage. And yes BrotatoChip lower bolt was loose as well. Tightened wing but then bolt. All good thank you for the insight

 
Rep Power: 134

This issue of loose alternator bolts (or failed alternator replaced with aftermarket one) is so common in these cars. When someone new mentions electrical problems with battery light on or flickering - this is 9 out of 10 times the reason.

 
Rep Power: 367

so all that is left is the ECU

 
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yep sure was, I知 glad I have u guys to help me out. Now that I know a little more about these cars, I can help others as well. Thanks to all who put their 2cents in, it helped a great deal. Car is running great now. I get a little pudder here and there, but going to replace all plugs and wires. See if that helps. Also have kinda of a whining noise when accelerating. Was told timing belt to tight? Any input gents?

 
Rep Power: 119

Glad we were able to help! The whining noise when accelerating could be an accessory or something with the timing belt. When was it last changed? I doubt it is too tight, these cars have an automatic spring loaded tensioner for the timing belt. Is there a specific RPM the noise happens at? Does it make the noise when revved up while sitting still or only while moving?

 
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honestly I can say both. I値l rev her up and about 4500 5000 rpm she will a whining noise. Same with driving. When I take it easy it痴 hard to notice because of the cannon muffler. Give it a little gas and You値l hear it for sure. You might be right with the accessories idea. Had a truck that did that with an aftermarket stereo. I値l unplug my deck and see if same. Thnxs for the ideas.

 
Rep Power: 119

The accessories on the engine (alternator, AC compressor, power steering pump) can make noise too if one of them is failing. What I would do is take the power steering belt off, rev it up, and see if it still makes that noise. If it does, remove alternator and AC belt as well and try the same test. If it still makes the noise with both belts off, you can eliminate those 3 components as possible culprits. If the noise stops, you narrowed the problem down to 1 or 2 components and from there it should be easy to figure out which it is. I've done that test many times and it's a very simple and effective way to rule out components. Hope this helps