Yesterday my Civic started doing something weird. When I first start the car the engine shakes like something is out of balance. After a minute or less it idles out and is fine; no problems while driving.

The first thing that comes to mine is possible dirty or messed up injectors. The previous owners were putting in top octane fuel into the car when it only needs low. I have put on nearly 2000 miles since I weened it off high octane fuel. I see no problems with MPG; its 30 or higher.

The last thing the previous owners did was have the timing chain replaced by a trusted Honda mechanic (I talked to the mechanic when I traded for the car). The cam sensor went out after the timing belt change happened which the same mechanic replaced.

Should I try some injector cleaner or could I have a bigger problem?

I tried to take a video but it wasn't as violent when I started it this morning. You notice it the most when I focus in on the steering pump.


Fuelly report for kicks:

 

Motor mounts.

Scan the CEL.

 

I forgot to add my car to the garage. Its a 2002 Honda Civic LX with no modifications and high mileage (190k).

I don't have a check engine light but I can scan codes myself (about to do that now, will post if I see one). After talking with a friend he thinks its either a dirty spark plug, injector going out, or ECT sensor going out (if my car has one) which detects if the engine is cold or hot. My car doesn't idle high when I first start it and sometimes I smell gas. One time a few weeks back it stalled on start-up like I flooded the engine (which should be impossible to do, flooding the engine did pop in my mind as odd but I didn't think twice about it then).

Edit: Code P0301 - misfire in cylinder one

Odd how there is not check engine light when there is a code...

 

00:41 on the video, there is a CEL.

Swap the injector to cylinder two, and see if you get P0302, then the coil, then the spark plug. Take it for a drive after you change something, and you should find your culprit.

Also inspect the harness for the coil and injector.

Have fun.

 

Thanks for the info. I don't know why I missed the light. I am going to try what you said backwards. Looking at the service records I see no time when the plugs were changed so I will get a good set of NGK plugs first and go from there.

I have the feeling its an injector but new plugs never hurts.

 

Take it to a professional... From the bit of information youve given us already, it seems that you are just going to cause more harm than good for this car. It shouldnt take a well-trained technician more than a hour to give you a proper diagnosis of your complaint.

 

Don't be silly, you can do this.

All you're doing is unplugging stuff.

Here's a tip, dip your finger in some oil or ATF and run it around the o-ring so you don't tear it.

 

Can't be any harder than replacing a clutch and head on a Toyota 22R, or taking 3 22RE engines and making one, or fixing a dozen diesel trucks Found On Road Dead. I even put an F150 lift kit on a Ford Explorer. I don't work on vehicles to make money but I know enough to get myself in trouble. I am not to new when it comes to Hondas. Usually they give me the least amount of problems. I had a 92 Honda Accord Wagon that I changed the distributor on and the radiator. Well, and the heater hose that I caused the leak on...

 

I put in new plugs. Moved cylinder 1 coil pack to cylinder 2. No problems since. Easy quick fix for now.