Long story short. 2001 Civic LX 5-speed manual with 160K. Civic has been properly maintained and no issues in the past. I tried to start the car and engine turned freely but would not ignite. I connected a code reader and no codes came up. I suspected a fuel pump issue but the fuel pressurized when*powering up. I suspected a cps problem so I replaced both crank and cam position sensor and after replacing the Civic started immediately. Drove the car to and from work today (40 miles) with no issues and*3 hours later I tried to start the car and I have the same issue*the civic will not start. Any advice on what the problem could be?
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Thanks in advance,
Figman

 

Any correlation between when it acts up and the cockpit heat levels. I believe there is a master relay module (could be called the fuel relay module) mounted under the dash which may be going intermittent when the sun heats up the dash area.

 

Much obliged, I will check it out.

Figman

 

Check codes again. When it won't start, crank a few times and then connect your scanner without turning the key off. Sometimes the ECU will forget codes whenever the key is off.

When it won't start, check that when you turn the key on but don't crank, the CEL comes on then goes out. This shows the ECU is booting up and running, at least to some extent.

When it won't start, pull up the hand brake and watch the BRAKE light while you crank. It should stay on. If it goes out there is likely a problem with the ignition switch cutting power to the ECU etc. while cranking.

 

I tried starting the car a few times over the past week but would not start. Yesterday I tried again and the civic started immediately and ran great. I let the car run a few minutes and refired a few more times with no problem. I think you may be correct that it is the relay. Where is the relay located (specific) on the 2001 Civic?

Thanks,
Figman

 

Did you end up changing the relay? I am having the same issue on my sister's car. When the car is cold, it starts like a champ, after driving for roughly 40 minutes and turning off the car, it won't turn back on. We replaced the Fuel Pump Relay, but the car was still doing the same thing. I did not think to replace the Main Relay. Please let me know, thanks!

 

Check for it here OEM Honda Parts Online

Should be able to get the main for pretty cheap