I have a 1990 F150 XLT Lariat that I am having a few engine issues with. I have been trying to perform a koer test but I am not getting any response from the check engine light. I checked the fuse and replaced the light bulb but still nothing. I think the diqgnostic is running because the idle goes up for a second once I start the truck. Does anyone know what I'm doing wrong?

 

im using a innova scanner. i can do a KOEO test no problem, but during the KOER test i get a message, Can not retrieve Cylinder id, continue running test until 11 or 111 appears. When i continue to run the test the scanner just shuts off. so i did it again and just kept pressing the enter button, the whole time the test is running the check engine light flashes mores code and engine idle fluctuates. i did this for about 5 minutes or more, and still no codes so i let the scanner be and then it shut off, once it shut off the engine rev'd quick then back to normal...

Im not sure if how to get around this, i sure hope some one can contribute some advise to this page.

 

OK I finally got the koer test going. I got a code for low voltage on tps so I replaced it this morning. The truck is running much better so I reset the codes and ran the diagnostic again now I am getting a code 13 which I think is the iac . why did I not get that code before? Do I need to replace the IAC or can I just clean it?

 

You can clean it but its usually recommended to replace it. Depends how dirty it actually is I guess.

 

MLPS the manual leaver position sensor malfunctioning can keep one from pulling KOER codes.