I have a good one for you guys. My '92 V6 p/u randomly turns on the check engine light and throws codes 14 (ignition signal) and 52 (knock sensor). When the check engine light comes on is relatively random, but I have noticed it more going from a stop or a steady cruise. Otherwise, this truck runs fine.

I've tried the knock-sensor-on-a-head trick, and it seems to reduce the number of times the check engine light come on.

What I've noticed is that the volume output from my stereo (factory) significantly reduces before the check like comes on. Actually, it's very consistent; when the volume output drops to near nothing, the check engine light usually comes on. When I turn off the engine and turn the key to the accessories position, the radio volume fades from full volume to very little volume in a couple seconds when the check engine light starts coming on.

At this point, my guess is that there is an electrical issue somewhere (bad ground, bad capacitor, bad rectifier, etc.) that's affecting the knock sensor signal circuit.

Anyone experience anything like this?

 

i would certainly start at the grounds (next to the battery in the fender, by the lifting hook on the passenger side, etc) and then check the fuses by the battery and at the kick pannel. your stereo going quiet is a good tell-tale that voltage is dropping off.

 

Every so often I will get the code 14 / 52. I usually just clean the the ignitor connector and ign coil connector with some deoxit and reseat them and all goes back to normal. I suspect the code 52 is happening becuase of the code 14. So if you can eliminate the code 14 the code 52 will more than likely go away. YMMV

Cheers
Andy