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Toyota Other Repair Question


Topics covered: Ignition coil, Spark, Compression.
Mileage: No information provided.

Asked on March 5, 2007

Cylinder misfires only on one (rear) bank?

Hello,
I have a 2000 Toyota Solara SLE V6 (3.0L), approx 130K miles.
Earlier today, the car began to run very rough at idle, and the Check Engine Light came on moments later. I scanned the codes and came up with P300, P301, P303, and P305. These are random cylinder misfire, and misfire on cylinders 1, 3, and 5 respectively.
The problem has replicated itself since, and typically all four codes appear. Cylinder 3 misfire appeared by itself on one occasion, and Cylinders 1 and 5 appeared by themselves at another time. The CEL flashes steadily. All the misfires have been confined to the rear bank.
I have cleaned the MAF, changed the fuel and air filters, and also all three A/F sensors. I have also tested with new plug wires (I have three plug wires that interface with the ignition coils).
I plan to change the plugs just as a baseline, though I did replace them about a year ago.
Finally, I will be testing with new ignition coils tomorrow.
I understand that a bad ignition coil can register multiple cylinder misfires - but since each coil interfaces with both front and rear banks, is this the probable cause (as my codes are restricted to one bank)?
I have also been advised that this problem could be related to the ECM or the fuel rail.
Beyond changing the plugs and ignition coils, I am unaware of how to troubleshoot this further. I am also unaware of what problems these vehicles are typically known for.
Any advice you could provide would be GREATLY appreciated.
Thanks.
Avatar Asked by aaron65527

Answer

Replied on March 6, 2007

The P0300 code is a random misfire code while all the other misfire codes denote a misfire problem in a specific cylinder. The last digit in the code tell a misfire in cylinder number one.

If a misfire in a specific cylinder should lead you to check the spark plug, fuel injector and compression.

Misfires can be caused by worn or fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel.

Check all of these and you'll run right into your problem area.

HTH-Good Luck!

Tiny Answered by rasmataz
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