I know there have been threads about this topic but here goes: 2000 Exp. w/5.4 over the past year I have noticed a knock that did not used to be there. Putting 93 octane does NOT seem to help. The pinging is not terrible all the time but going up hill with the trailer, it can be bad. Since I hit the 100k mile mark, I decided to do the following: Replaced: plugs, IAC valve, EGR valve & sensor. Cleaned the MAF sensor, throttle-body and air temp sensor, and ran 2 bottles of SeaFoam through the gas tank. I also had the dealer perform their intake system cleaning to (hopefully) get rid of carbon buildup. The fuel filter only has about 15,000 mi on it.

How do I test a knock sensor?
How do I test fuel pressure during load?
Could the injectors be causing this? If lean, I figure the computer would compensate by opening the injectors longer.
How can I monitor sensor readings while I drive?

Please help! Any ideas will be appreciated!

 

I'll bet you're onto something with the knock sensor. The 2V engines are very knock prone due to the intake design,and most all of them run off of the knock sensor all the time. I noticed awhile back that my F150 would knock almost all them time if I leaned on the throttle at all-and it's a bad knock sensor. I've got tuning software here,so I just disabled the knock sensor parameters,and dropped about 5 degrees of spark adance out of the timing table to keep it from knocking. Problem solved. The only way I know of to check the knock sensor it to live datalog it while driving. Log the knock_sensor_retard parameter,and see if it's pulling any timing when you hear the knocking. If it's not-it's very likely that the the knock sensor is bad. I'm not pulling the intake to change mine-it'll just have to stay disabled for awhile until I get the other engine here to swap in.
If the injectors were partially clogged,then you'd have lean codes after the EEC adjusts to a certain point.
JL