I started my car up this morning and got a CEL CODE 72 (random misfire). So I decided to turn the car off and then on again...CEL still on. So I drive to work with the CEL light on. After work I start the car up and no CEL light. (If it makes any difference, I was getting slightly low on fuel though the empty light wasn't on yet.)

I replaced the spark plugs, distributor cap, and rotor about 2 months ago. Theres approx. 70k on the car right now. The car idles fine and there doesn't seem to be anything wrong. Should I be worried?

Thanks!

 

Were the spark plugs pre-gapped or was it gapped by someone else?
It's possible that a spark plug is fouling. I believe the second number 7(2)<---- indicates where the misfire occurs (Cylinder 2).

Cel 72

From 98+ service manual
Possible causes of a random misfire. P0300 (71-74)
Ignition system
Fuel supply system
MAP sensor
IAC valve
Contaminated fuel
Lack of fuel

Possible causes of a detected misfire . P0301-P0304 (71-74)
Fuel injector clogging, fuel leakage, air leakage
Fuel injector circuit open or shorted
Spark plug carbon deposits, fouling, malfunction
Ignition wires open, leaking
Distributor malfunction
Compression low
Valve clearance out of spec





Modified by mastamind at 6:52 AM 7/7/2005

 

The plugs were pre-gapped. Denso double platinum.

 

One way to eliminate a faulty spark plug as a possible cause would be to exchange the problem cylinder plug for a different cylinder plug. If you get a different cel code (71/73/74) after the exchange then you have the answer to your problem.

For a fuel injector listen for a clicking sound at the one in the problem cylinder.

I wouldn't personally ignore a misfire because it could be strong enough to damage the catalyst/increase emissions.

 

Thanks for the help mastamind. Yeah...I was hoping that since the light turned back off then it was just "random." But I'll definitely check everything you suggested above.

 

No problem, don't get overwhelmed because it could possibly be a very simple fix. Post up any updates on this issue in this thread.