My 93 F-150, 302, startd having valve ping/spark knock about 2 months ago...all of a sudden. Only has 44K actual miles, but I changed plugs, wires, distrib cap and rotor, and several brands of fuel additive to clean the carbon from the combustion chamber, and yes, even ran a tank of 93 octane fuel through...no change. And I tried different gas stations too. I tried the poor man's diagnostic but I'm not very sure about that. I did it many time times and the only consistant codes I got out of the engine off test were 33, 16, 34, and 63. The codes during the engine running test were 53, 86, and 32. But like I said, I don't have a whole lot of confidence in this check. I'm not always sure when to count, stop, or question wether I really got a flash. Anyway, the common codes are for the throttle position sensor. That won't cause valve ping will it???? It runs and idles fine. The codes 86, 33, 16, 33, and 34 don't have any refereces in my Haynes book...what do they correspond to? I really don't want to take it to a dealer, but changing all the sensors one by one can get expensive too. Any suggestions?

 

Code 86: Shift solenoid circuit failure
Code 33: EGR valve opening not detected
Code 16: IDM signal not received
Code 34: EVP voltage above closed limit
I have no idea what is wrong but I hope these codes help.

 

Thanks! That must be some book you have. Shift solenoid? Is that like transmission shift? Cause that's an annoyance I haven't gotten around to working yet...shifts way too fast. Hmmm, could EGR and EVP cause valve ping? Other than pinging the truck runs pretty strong. EGR maybe...too many computors and too many sensors. Maybe I should just get a truck from the 1960s...one I can work on without a PHD in electro physics. I guess I'll do the tests on those two components and see what happens. Thanks alot for the info.
The Ping-Master

 

I fixed it!!!!! Just got to thinking and easy thing to try would be letting the computer reset...been about 3 years since the battery has been unhooked. Took the neg cable off for about 30 minutes and low and behold that did it!! It cut the ping by a good 90%...a little is to be expected I suppose. Now I'm going back and rerun the poor man's diagnostic and see what turns up there...just for curiosity. Who would have thought...D*mn computers.