Misfire 98 LX 2.3l
 

Hi Folks,

First time poster - bear with me!

My 1998 LX began running rough intermitantly about 2 weeks ago, usually around 2000 rpms hot or cold. Added fuel injector cleaner - no luck. Then this week it has been idling and running rough at all rpms hot and cold. Pulled codes and got P0300, P 0301, P 302, and P1399. As I understand it basically a Cyl 1 & 2 misfire.

Ignition Control Module, Plugs and wires were replaced 3 yrs ago at 166,000 mi, so I thought maybe loss of compression? But, compression testing showed no low compression:

Cyl 1: 215 psi
Cyl 2: 218 psi
Cyl 3: 208 psi
Cyl 4: 218 psi

Oil looks good & no oil in antifreeze. Plugs look normal for 30k mi, no excess carbon, not wet. Where to go from here? I'm thinking of replacing plugs, wires, and distributer cap as a start?

You might try the "shower test". Spray wires and distributor w/ fine mist of water w/ engine running at night and look for sparks jumping from wire to wire, wire to ground, or distributor to ground. Replace components as indicated. Suggest changing the rotor in any case, since a fine crack can cause arcing to ground.

Try disabling the EGR valve. A sticking EGR valve might cause missing, but I thought the ECU was capable of detecting this condition. So perhaps a long shot. More likely an ignition problem.

good luck

I changed the rotor, distributor cap and the plugs last night. Had to quit before I could do the "shower test". But I really wanted to try that, it sounded cool. What was interesting was that after disconnecting the battery, and then reconnecting and starting, the car started and ran great for about 3 minutes. Just when I thought I had it beat, it started misfiring again, although not quite as bad. I'm going to look at the EGR valve next. Any other thoughts?

I unplugged the wire connector to the EGR valve - no improvement.

In researching other threads here there was a suggestion to clean the throttle, so I removed the air box and cleaned throttle body. Seemed like a lot of carbon build up on the engine side of the throttle. Pulled the EGR valve, also a lot of carbon soot build up on bottom of valve and ports in from engine and out. Cleaned up valve w/dental tool and carb cleaner. I didn't clean ports because they are still open and didn't want to dislodge soot that I couldn't get out. still rough running from idle up to about 2800 rmp.

Replaced Autolite "pro series" spark plug wires w/NGK. Connection of wires to the distributor seemed much tighter. Car running smooth! I think that was it. This doesn't bode well for Autolite in my book.

Seems like Hondas have always behaved best with NGK plugs.

I've used Autolites platinum plugs w/o problems in several Hondas and Acuras, but never tried their wires. I agree the NGK wires are top of the line. Sounds like it could have been a fit problem for the Autolites.

Good to hear you resolved the problem.

good luck

thanks for your suggestions. Drove the car all weekend without any problems (knock on wood), so I'd say it's case closed!