1992 Aerostar 3.0L auto, 222,000 miles. At idle speed the timing is 10 degrees BTDC, which is correct. On increasing the engine speed by a few hundred rpm the timing retards to about 0 degrees BTDC; a few hundred rpm more and the timing advances back to 10 degrees BTDC, and stays there until the engine speed is increased to about 1900 rpm, at which point the advance jumps to 20 degrees BTDC. The advance does not move smoothly between 10 and 20 degrees BTDC no matter how slowly I increase the RPM - this 10 degrees of advance comes all at once. There is no further advance, even at very high rpm. As the manual advises, I did disconnect the single SPOUT wire before doing these tests. (I subsequently performed the tests with this wire connected and got the same results). I don't know what the timing characteristics should be for this van but these figures don't seem right to me. The van lacks power which is why I checked the timing. I replaced the distributor cap, rotor and spark plug leads (which were probably the originals as they had "1992" printed on them), and the Ignition Control Module. None of this made any difference. I checked for codes and got the following results: KOEO test: code 111 (ok). KOER test: part of this test attempts to advance the ignition timing by 20 degrees to 30 degrees BTDC. During the test the ignition timing only advanced by about 8 degrees to 18 degrees BTDC. Any suggestions would be appreciated. Jan