Portland Mobile Auto Inspectors will offer the following tests for a used car inspection:
Cranking History Test:
This is a test for the strength of the battery. A battery reading above 9.60 volts would indicate a good battery. Alternator amp readings show the alternators ability, or inability, to keep the battery charged.
Electronic Compression Test:
This test shows engine cylinder compression (power) uniformity. Good compression is shown by a high % number with all readings being within a 10% range.
Ignition Primary Test:
This test looks for bad primary components such as the ignition coil.
Spark Burn Analysis Test:
This test looks for bad secondary components such as ignition wires and distributor caps. 0.8 to 2.3 burn time milliseconds is the typical range limits. Short burn times could be caused by breaks in ignition wires, a worn rotor button, etc. Long burn times could be from fouled spark plugs, a rich fuel mixture, etc.
Power Balance Test:
This test measures each cylinder contribution relative to the others by turning off the spark plugs one at a time. All of the % drop numbers should be within 10% of one another. Out of range readings will be compared to other tests to confirm a problem.
In addition to these major tests, the following other information will be determined:
The results of the inspection are delivered on the spot in a 100 point inspection regime. From the information provided with the inspection, the client will know exactly what is wrong with the car. This is useful because depending on the condition of the car, it might dissuade the person from purchasing it, or will be used as leverage to reduce the price to account for the needed repairs.