2000 Civic LX

In the past few days, I've noticed that my idle is really rough and low when I stop at a stop light. When I have the car in gear and have the AC on, it gets bad. When I put the car in neutral, it helps just a little, but the idle is still rough. When I turn the AC off, the car is still idling a little low, but it's not as bad/rough.

Also, I noticed that I've got a nasty **** stain on my rear lip from my tail pipe, like the car is running really rich or something. I know I go through a lot of oil, but I don't know if that would cause the mess on the bumper. I've never had it gunk up the plastics before.

No CEL, CEL works. Any ideas?

 

Anyone?

 

Really? No one?

Now the car is dying at intersections.

 

I am getting a low idle also on my 98 but when the ac is on it stays the same no balck smoke but runs great when crusing still cannot get any help neither

 

if its running rich you'd assume it was the o2 sensor, no? but with no cel, that is really odd...

 

I've already swapped the primary O2 sensor. Header has the typical crack that the 96-00 ones get.

Today I cleaned my IACV. Started it back up, drove a little, no change. IACV was surprisingly clean for never having been taken off after 139000 miles. After this, I seafoamed the engine. I followed the 1/3 in the tank/crankcase/intake method. Got tons of smoke, was lots of fun, drove it for 20 minutes on the interstate, still does the same thing (though not as bad)...

Ugh. I just need this engine to stay dependable until the new one goes in.

 

Before I replaced my engine, the back of the car was black from oil smoke. If you can see clouds when taking off from a stop, it's going to smoke up the bumper and stuff.

Cracked manifold though, the ECU will think it's running lean due to O2 leaking in through the crack, will run too rich to compensate.

 

Had a strange turn of events today. My car has been idling very low when at intersections or when parked. MPG is down to 25 or so. Engine is just going to hell, etc. But today, I was sitting at Sonic parked, AC on, and it was idling fine for once: a nice healthy 800 RPM idle.

BUT the CEL was flashing. It flashed for about 30 seconds, turned off, and kept idling the same. Then intermittently, it would come on again, flash for a bit, then turn off. Idle remained healthy. (Sad to be worried that it was running nicely, right?)

I took it straight to Autozone and borrowed their scanner. Threw code P1399. Misfire in any cylinder. I cleared to code and it hasn't "misfired" again yet. But I haven't gotten to drive it much because that was on my lunch break.

I've driven that car when it was misfiring on 1 cylinder AND when misfiring on 2 cylinders. This time it wasn't misfiring at all.

The car has gotten new plugs and wires in the past 6 months. It got a new distributor cap in the past year and a half. Not sure where to look next.

 

1) Test the coil and have the ICM tested at an auto parts store.

2) If you installed an aftermarket distributor cap and rotor, consider replacing them with OEM.

 

I don't suppose you have a how-to sheet on the coil test? (I'd like to get the ignition fixed before I swap these parts over to the new engine on Saturday.