I was fianally able to buy a code scanner. Studied the procedures and did the tests. I have a 93 ford explorer 4.0 eddie bauer. The reason I bought the scanner is because the engine revs for a second then drops back to normal 500-600 rpm, in all gears. It has EEC-IV OBD II. For the KOER test it gave me a code 538. In the manual it says "insufficent rpm change during KOER dynamic response test" or for trucks only "invalid cylinder balance test due to throttle movement during test". My Chilton book doesn't have KOER codes but the other two test's it says (code p1538) "intake manifold runner control (IMRC) fault". I looked on the internet and I've found "System did not receive "goose" test - TESTS" (OBD I? it doesn't say). Which definition do I go by? Isn't the scanner supposed to make it easier to diagnose a problem, not make it harder? I appreciate any help, I'm confused!
it will usually give you that code if you don't "goose" the engine hard enough during the KOER test. next time you run the test, try getting on it a little harder when it tells you to "goose" it. or did it not prompt you to do it the first time?