I have an odd issue with Spark Knock. Odometer has 216k, but I believe the engine and trans has been into.
Spark knock appears at mid throttle. Give it more pedal and it goes away. Lighten up a bit, and it goes away. I have replaced the O2 and the MAP sensor, made no difference. The distributor is not adjustable. Anyone have a guess? Engine is a 5.2lt.


Thanks a bunch
Ron

 

You sure it's not a rod knock?

 

I got to think it's so spark knock...marbles in a can. Oil pressure is fine. I started in a hot rod shop 25 years ago some familiar with the different noises. It started with the MAP going bad. It's darn odd. As I said ONLY part throttle.

 

Check the sweep of the TPS, you might have a dead spot and causing a lean condition.

 

There is a new idea. I'll give it a try!

Ron

 

Lets start back on this again.
Changed the MAP sensor over to a different brand. Still there.
Had a suggestion that all of the sensors stacked up are almost at spark knock, the when it drops to 10 inches of vacuum it sets it off. Only sensor really left is crank position sensor.

Best I recall this is the SOB on the back of the block.

Ron