Toyota Repair: misfire on 1997 Camry, vehicle speed sensor, intake air temperature

Question
QUESTION: My '97 Camry LE(2.2 l, auto, air) has been running rough for some time.  Initially it would miss on acceleration, whether hot or cold.  The codes I was getting off the on-board computer were 300, 301 and 304.  Since the misfires were on cylinders on opposite ends of the motor I ruled out head gasket.  Since they share a common coil that seemed a reasonable place to start.  Replaced the coil and had same problem.  Figured there was some deferred maintenance I could do anyway, so replaced the plugs and the PCV valve. I also ran some injector cleaner. (Added to the gas)

When I was replacing the plugs I noticed a crack in a vacuum hose.  Trimmed back to where it was good and it seemed OK.  

Cleared the code and seemed OK for a while.  Now it is idling rough and the rpm's are fluctuating.  Is OK on acceleration now, but tonight the check engine light came on and was 304.  I'm assuming I could generate more misfires on 1 and random misfires if I ran it longer.  Below is the information off my ODB freezeframe:

DTC for which Freeze Frame was Stored     P0304
Fuel System 1 Status    Closed Loop
Fuel System 2 Status    Not Supported
Calculated LOAD Value    32.94 %
Engine Coolant Temp    185.00 °F
Short Term Fuel Trim - Bank 1    -2.34 %
Long Term Fuel Trim - Bank 1    3.91 %
Intake Manifold Absolute Pressure    9.77 inHg
Engine RPM    665.75 rpm
Vehicle Speed Sensor    0.00 mph
Intake Air Temperature    68.00 °F

Any suggestions on what I could check or try next?

Thanks!

Tom

ANSWER: The V-6 engine shares the same coil for cylinders 1+4 but you said it's a 2.2 L engine which is a 4 cylinder which has a coil for each cylinder, is it a V-6 or 4 cylinder engine?

---------- FOLLOW-UP ----------

QUESTION: It's the 4 cylinder.  There are two coils, one for 1 and 4 and the other for 2 and 3.  Since the original error code was coming up with misfires on 1 & 4, and random misfires, I replaced the coil on 1 & 4.  Didn't help.  Now it is idling very rough but seems to accelerate smoothly.

Thanks for the help!!

Tom


ANSWER: On the 4 cylinder engine each coil fires one cylinder, they are independent of each other and not paired with another cylinder so if you have a code 304 the misfire is isolated to that cylinder only. Did you replace both coils on 1+4 ?

---------- FOLLOW-UP ----------

QUESTION: This particular model has one coil for 1 & 4 and one for 2 & 3.  (here's a picture of the part I replaced:(although I'm not sure if the picture is 1 & 4 or 2 & 3) http://www.1aauto.com/1A/IgnitionCoil/Toyota/Camry/1AECI00147/372478/1997   )

I see there is a resistance test for the coil, so I think I'll check the old and new one to see if perhaps I have a bad NEW coil, but any thoughts you have would be appreciated!

Thanks

Tom  

Answer
Ok, that clears it up a little for me, right after toyota got rid of the distributor they introduced the two coil configuration, the old coil should have the cylinder numbers stamped on them and you already replaced the coil for those cylinders. Since the dtc is now for #4 cylinder only I would suspect either low compression on that cylinder or a bad fuel injector but looking at the freeze frame data the fuel trim seems normal. Just to be sure can you check to make sure there is injector pulse to the #4 cylinder?