Rep Power: 0

My kid has a 2001 Civic LX AT, this problem started without warning. He said it wouldn't start, it was cranking over but no start during the day but when I got home later that night it started up just fine.. I did it 4 times and it worked without a problem. The next morning it started right up, but then again in the afternoon it didn't start again. I got home and decided to try a few things. Replaced the spark plugs and it didn't solve the problem. I thought maybe it wasn't holding fuel in the rails after sitting so I primed it by turning the key on and off several times and starting it, that worked a few times. Replaced the fuel pump relay, won't start even tho I hear the fuel pump whirring. Long story short is I'm not sure where to go from here, I don't have a fuel pressure tester but I think I found the check valve (green cap behind the drivers side of the head). Other than that I'm thinking about replacing the fuel pump and checking the coils. Any advice would be appreciated.

 
Rep Power: 517

You're probably gonna need to make this problem act up, then troubleshoot WHILE it's still acting up.

Once it will run on its own, the problem is no longer present and you're back to making more expensive wrong guesses.

Nope, and don't touch that cap. It's for testing the evaporative emissions system, not fuel pressure.

Does the computer already have the answers you seek?
Got check engine light?
Got fault codes?
Got scanner datalist?



Compression, fuel, and spark. In the correct quantities and at the correct times. Which part isn't perfect?

 
Rep Power: 0

CEL came on and stayed on last night, got the scanner today and will attack when I get home from work.
Thank you for telling me not to touch the green cap. hahaha.
When it finally does start it runs shitty for a couple seconds then runs fine. Problem seems present mostly when it's warm outside until last night when it wouldn't start at all. Exhause manifold has a crack which I learned was common, so I'm getting that welded up (I just need the car to work for another year.. that's all).

 
Rep Power: 0

So I had the car running yesterday. It ran fine the whole time. Replaced the Fuel Pump Relay and the ELD (had a code for that so I replaced it), took it for gas and it wouldn't start again. It started up just fine from cold but once it warmed up no start. No check engine light. I've been reading about a possibility of a leaking injector or a Main Relay going bad.. Any ideas?

 
Rep Power: 517

Check out what's happening at the times it will not start,

Turn the key on and wait a second before cranking, look at:
Does the check engine light actually light up on the dash before you crank it? If not, that may mean the PCM isn't getting powered up, like an intermittently flaky main relay.

At the time it won't start....
Have you pulled out a coil to verify spark is or isn't present?

Maybe you can try a brief squirt of flammable spray (carb and throttle cleaner directly into the throttle body) to see if it will try to fire on an alternate fuel source. THat would indicate spark still works but it needs more fuel for some reason, and maybe give a direction to pursue further.

I'd probably want to see a good scanner and have a look at live operating data, like see if the coolant temp sensor is reporting a seriously incorrect temperature or MAP is way off, or anything in the data is amiss that could explain a bad warm restart condition.

 
Rep Power: 228

Just a few dummy checks

-are both battery terminals tight?
-is the battery testing well (especially since you mentioned hard starts while in different temperatures)?
-is the ground wire going to the head in good condition and tight?


Have you or your son done or had any work on the car done within the last 3 months?