Hi, new member, new Civic owner.

I just bought a 94 DX with a whole load o' miles on it, but my only concern right now is my engine.

It starts and idles fine, and runs great cold. Once it has warmed up, however, it bogs & misfires heavilyin the middle RPM range (no tach, so don't know the revs exactly) when under load. I have to rev quite high to prevent this and get any power out of the engine.

I just got it and the PO mentioned that it gets 280 miles to a tank... EPA says 34-40MPG, so shouldn't it be getting 300-380 miles per tank?

CEL is on, but I can't find any instructions anywhere on how to blink codes on this ECU.

My thought is: rich mixture. Bad O2, bad water temp sensor (are there two water temp sensors in a Civic or only one?) or failing ignition components (coil, dizzy, plugs, wires..)

Thoughts? I'd really like to know how to pull codes, since the ECU seems to know whats wrong.

Thanks!

 

All right. Pulling codes was a snap.

As per http://www.c-speedracing.com/faq/06.php Jumper the 2-wire connector coming from the ECU, which is under the outer wall of the passenger's side of the dash.

OK.

I get a LOOOONG, short short short short. 14. Thanks to http://www.c-speedracing.com/faq/05.php I found that a 14 is the IAC valve. Fine. This I knew. So what about the bogging?

Every post about bogging / rich mixture in the forum says: "O2 Sensor" and "maybe cracked exhaust manifold." Woot. JB-Weld time then.

Well, though I received 0 replies, the forum was a huge help! I'll take off the heat shield tomorrow and check the manifold. I'll order the O2 sensor soon.

Thanks for the info!