My '95 f150, 5.0, is pinging while I'm towing, mostly when I loadup in the highway gear, up hills. I've heard there's a problem with the #8 cylinder detonating, 93 octane helps a little, any ideas?

 

You can start by checking out my thread (pre-detonation) about five below yours.

 

Any CEL? Codes?

Try unhooking the vacuum line to the EGR valve and see if it changes. If so, the EVR solenoid may be leaking.

Clean the MAF sensor filaments.

Try running with the MAF disconnected (you will get a CEL that can be disregarded).

Be on the lookout for vacuum leaks.

Steve

 

sounds like you need to get the timing adjusted. on a '93 the timing can be adjusted.