Mechanics

SPUTTERING/STUTTERING WHILE ACCELERATING AND HOLDING SPEED

Honda Civic

I have a 2002 Civic Si, the chassis has approximately 90k on it, with a motor that is in the mid 40's. Recently my car started to expirience a sputter or backfire while holding speed on the freeway. I checked the plugs and they appeared to be fouled with oil, so I replaced them and got new valve cover gaskets to go along to change any chance of it happening again. It seemed to work, for about a week, but it came back. It has now gotten to the point where I don't want to drive the car, as I don't want to make the problem worse. It is also now doing it under acceleration, not just while cruising. I have exchanged the following parts from a known working car; coil packs, map sensor, fuel pump/filter, fuel injectors, fuel rail, throttle body, main relay 1 and 2, ECM and intake manifold has been cleaned, air filter is in good condition. There are no codes on the ECU. No cat-converter is on the car. Yet the problem persists. I do not know what else I can change to get it to go away.
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Mdoyle
May 8, 2006.



Replaced the plug wires? Have you had the timing checked as well? When you pulled out the fuel filter did you dump out the contents and note if any moisture was in the gas? Any your fluid levels dropping? Have you done a compression check? I would look at these items. They are reasonably inexpensive and can tell many tales about what is happening in the engine.

Bruce Hunt
May 8, 2006.
Coilpacks were changed with good units, compression test and leak down test were both done and nothing is out of spec. Timing is perfect. I didn't dump the contents of the old filter out, but did replace it so I don't see how that could be a problem. I have also checked for any loose connections and vacuum leaks.

Tiny
Mdoyle
May 8, 2006.
Reason I asked on the filter was for water in the system. Sometimes something so useful is so harmful. Water in the system can cause the symptoms. Wires, Wires, Wires. Simple stuff before the deep stuff.

Bruce Hunt
May 8, 2006.
The newer Honda's (the K series motor) do not have wires, they have coilpacks, which I have already changed, as stated in my previous posts.

I might try draining the tank then, it's nearly empty anyhow.

Tiny
Mdoyle
May 9, 2006.
Sorry I forgot about the newer engines and no wires. I have to keep kicking myself on that.

Bruce Hunt
May 9, 2006.
Thanks for the suggestions, i'll be draining the tank later today and putting in some high octane fuel to see if maybe there is something left in the lines.

Tiny
Mdoyle
May 9, 2006.
Well, after another day of swapping parts we finally narrowed it down to a bad Primary O2 sensor. Again, thanks for the help.

Tiny
Mdoyle
May 10, 2006.