View Full Version : 97 Civic EX Misfire

05-06-2009, 03:07 AM
My Car Misfires Only When The Engine Is Cold And I Let It Idle. Once It Gets Up To Normal Operating Temp It Doesnt Misfire Anymore. Another Thing I Noticed Is When The Engine Is Cold And I Start It, As Long As I Step On The Gas Pedal And Keep The RPM's Above Normal Idle It Will Not Misfire. I Have Changed The Spark Plugs And Wires And Checked The Timing And Nothin Has Seemed To Work. I Did A Compression Check And Cylinders 1,2 and 3 Are Slightly Above Normal But Within The Limits In The Haynes Manual. Cylinder 4Is The Only One That Doesnt Misfire According To The Scan Tool. I Bought A Complete Fuel Injector Cleaning Kit By 3M And That Didnt Help. Is There A Part Of The System That Would Only Fail When Its Cold? I Also Checked For Vacuum Leaks And Everything Is Good. I Followed The Book And So Far Nothing Has Helped. I Think The Next Step Is To Check The Coil And ICM But If Both Of Those Check Good Then What Else Should I Check For? The Weird Thing For Me Is The Fact That It Only Misfires On The First Start Of The Day And Only If I Let It Idle On Its Own. After It Gets To Normal Temp I Can Let It Idle All Day And It Wont Misfire. Please Help....

05-08-2009, 03:48 PM
Hi tr0njecks,

So, no trouble codes have set? That's a tricky one. Unfortunately it's really not possible for us to diagnose problems from a remote location, especially something like this.

Try pulling the spark plugs (before the engine warms up) and see if they look rich or lean. That might give you a clue as to what to check next.

Sorry we can't be of more help, but let us know what you find. Good luck with that.