I have owned my 1999 Honda Civic HX since new. It has 260k miles on it. I am having trouble diagnosing the problem. It will start for a second, maybe 2 seconds then die. I have replaced the fuel pump, main fuel system relay, cap & rotor, fuel filter and the ignition switch.

If I start with no throttle, it will run for about 2 seconds, then just die. It will die immediately with any throttle.

Tried to read the codes, but scanner won't sync.

Can anyone help me out?

 

This could be something with the ignition switch or wiring. Attempt to start, after it stops, don't touch the key. Watch if the oil and battery lights come on. They should be on because the ignition is still powered up. If they don't come on, that's likely a bad switch, fuse box, etc.

If not that, pull a diagram, turn key on and probe all the power and ground pins on the ECU. The power ones should have power and the ground ones ground. If you have power and ground to the ECU but it won't scan, it's probably a bad ECU. Also test the the 5 volt sensor circuit, the 5 volts is regulated by the ECU.

 

I had hoped it was the ignition switch, but I just put a brand new OEM switch and ignition lock assembly in. No change.

Oil and battery lights come on after it quits.

 

So with the switch at "run", do you actually have power to everything? Another place to test is the yellow and black wire that powers the distributor.

 

Yup, with switch in "run" position everything works. I guess it could be the ECU or the distributor.

Tried to keep from paying $80 diagnostic fee at the dealer, but I've spent way more than that trying to figure this out. I've worked on cars all my life, and I'm stumped with this one.

 

I have a 1997 Honda Civic, when trying to start it, sometimes it turns over when I turn the key and sometimes it takes about 30 tries to get it to turn over. I've bought a new starter, changed the ignition clutch (i think that's what it's called) this is where I put the key in and turn it to start the car. Do you think I need to buy an ignition switch now? I bought the car about a month ago.

 

As an update, I just replaced the ECU. The car still starts then dies. I have run out of ideas. Has anyone else experienced this?

 

My car has a kill switch on the fuel pump. Without the switch on the car will start and then die, almost exactly how you describe. I know you said you replaced most of the fuel system but maybe its worth going over again. See if the pump is keeping the line pressurized or something like that. Wish i could give you a specific answer, sounds like a headache -_-

 

My guess now would be distributor, either ignitor or coil..

Did you do anything to the car before this issue occurred ???