so I bought a OBD 1 scanner the other day for my 1997 F350 7.5L and when I went to do the key on engine on test. its suppose to tell you how many cylinders its testing right. Well it said it was only testing 6 cylinders and not 8. any ideas on why that is? I redid the test a few times and it says the same thing every time. I bought the INNOVA 3145 Ford Digital Code Reader if that helps at all. Thanks

 

Run the KOER self test using the common paperclip/CEL method and see what Cylinder ID the PCM is sending out and see if it matches what the Innova is displaying.

 

Dynamic engine tests like cylinder balance only work with MAF vehicles because MAP based systems do not have control over individual injectors.. they are fired in batches. You will find notes for this at various locations in the documentation for the Equus code reader.