civic hesitates (stutters) between 1500 and 2000rpm

Recently my 2000 civic sir (si in the US) has started to hesitate or stutter
periodically. It happens between 1500 and 2500 rpm and I beleive it's
usually when it's warm, and I'm accelerating from a stop. Any ideas what
this could be?

 

You changed the fuel filter?

Checked air filter?

Had any work done under the hood, where some one could have pulled a
vacuum hose lose?

Changed the fuel cap?

 

I have recently replaced the air filter, changed oil/filter, and pcv valve.
The problem started shortly before I did this.
If it was a vaccume hose issue, how can I track down the leak?

 

you'll almost certainly have codes stored in the computer. read them,
then report back.

 

I hooked up a computer two weeks ago when it started,and there were no
codes. My girlfriend said the check engine light blinked a few times on her
way to work, so I'll check again. Haven't seen the light come on since.

I'll check again this week.

 

No codes. I was able to get the engine light blink a few times. I was
accelerating from stop, and the engine was hesitating, kind of boggin down.
I floored it and after about two seconds the engine light blinked 5 or 6
times. After about 5 seconds the engine started responding properly and the
engine like went away. No codes were saved.

 

don't believe you! how did you try to read them?

 

I've got an obd2 code reader. It connects with a green light and no codes
are reported. I know it works because we've connected it to other vehicles
and it's reported codes on them.

 

For the experts: does this sound like distributor trouble?

 

in that case, look into the ignition switch. for your model year, there
was a recall because the switched burnt out - and symptoms were odd, but
left no code like you describe. it's particularly bad if you have a
heavy key ring. try using the key on its own and making sure you
manually return the key fully to the "run" position after cranking
rather than letting it turn back with just the spring. the spring's not
very strong, and particularly with a heavy key ring, the contacts only
partially engage, overheat, and burn out. and of course, replace the
ignition switch if this turns out to be the cause.

 

Maybe but with modern cars with 'puters, it's hard to tell.

JT

(If it has a "Check Engine" light, I won't own it!)

 

I was finally able to get the check engine light to stay on and codes to be
saved. They're missfire codes and it turns out the misfire monitor requires
2 consecutive trips to trigger the DTC.

The codes are P0303 (Cylinder 3 misfire) and P1399 (Random/Multiple
cyclinder misfire).

Reported data is as follows:

Report#: 1
Report Date: 4-16-2007 (8:34 PM)
Vehicle Year: 2000
Vehicle Make: Honda
Vehicle Model: Civic (SIR)
Vehicle Engine Size: 1.6L
Vehicle VIN:
Vehicle License Plate:
Vehicle Mileage: 1230000

Stored:
P0303 Cylinder 3 Misfire Detected

Pending:
P1399 Random / Multiple Cylinder Misfire Detected

MIL ON
MisFire Monitor Complete
Fuel System Monitor Complete
Comprehensive Component Monitor Complete
Catalyst Monitor Complete
Heated Catalyst Monitor Not Supported
Evaporative System Monitor Complete
Secondary Air System Monitor Not Supported
A/C System Refrigerant Monitor Not Supported
Oxygen Sensor Monitor Complete
Oxygen Sensor Heater Monitor Complete
EGR System Monitor Not Supported

DTC for which Freeze Frame was Stored P0303
Fuel System 1 Status Open Loop - due to driving conditions
Fuel System 2 Status Not Supported
Calculated LOAD Value 94.12 %
Engine Coolant Temp 138.20 °F
Short Term Fuel Trim - Bank 1 0.00 %
Long Term Fuel Trim - Bank 1 -4.69 %
Intake Manifold Absolute Pressure 28.05 inHg
Engine RPM 3256 rpm
Vehicle Speed Sensor 32.93 mph
Intake Air Temperature 59.00 °F
Absolute Throttle Position 92.55 %

 

check the ignition componentry [distributor cap, rotor, leads and plugs]
and ensure its in good condition - if old, suggest replacement as a
precaution. random misfire on all cylinders can be multiple problems,
but misfire on #3 is injector or ignition componentry. injector cleaner
might be a good idea too.

 

Thanks for the tips. I'll look into these. The thing I found odd was that
the behavior only manifests when I'm excellerating, usually from stop or if
I punch the gas, and the car has warmed up.

 

that's consistent, particularly with aged plugs. for spark plugs, the
sparking voltage depends on the gas pressure, composition, etc in the
cylinder. if the plug is leaking slightly [electrically] or the
electrodes are worn, it may spark at one cylinder condition, but not at
the other. same can go for aged distributor caps/rotors.

 

Good call, turns out I was able to fix the problem simply by changing the
plugs. The old ones didn't even look that bad. Glad I didn't take it into
honda, the honda dealership here is terrible, I'd be surprised if it would
have came to less than $200 or $300 by the time they got through with it.

 

Thanks for letting us know what the problem was - it helps the next guy.
What brand were the old plugs?

Mike

 

The old brand I was using were Bosch. I've gone with NGK this time. It's
one of the brands Honda recommends in the manual.