I have a 4.0 liter, V-6 ext cab ranger....with 168k miles and significant pinging and knocking...I have tried high octane gas at 91 but it does not help...i have changed plugs and wires as well...no overheating at all

How do I check to see if the timing is set correctly...?...the book I have is unclear and does not show or explain exactly how to get to the area where the notches and markings are...it also does not explain how to change or rotate the pulleys or parts needed to get it right if it is off...

I need details...!

 

The reason it doesn't explain how to adjust the timing is because the timing isn't adjustable on the 4.0. It can be checked, however. See "ignition timing tests" at www.dalidesign.com/hbook/eectest.html On my Explorer it's pretty hard to get the light to point down at the crank pulley with the air intake tube in the way, but it can be done. One other note, The harmonic balancer has rotated relative to the crankshaft so it reads ~180 BTDC when it's really at 10 BTDC. If the timing looks way off, make sure TDC on the pulley means TDC at the #1 cylinder.

That said, there are several common causes of spark knock on the 4.0 that aren't related to the timing. In fact, timing is almost never the problem. The problem is either carbon buildup in the cylinders or the engine running slightly lean.
For carbon buildup in the cylinders, get some decarbonizing treatment (Seafoam or equivalent) and run it through the engine.
For a slightly lean mixture, 1) Clean the MAF filaments.
2) check for vacuum leaks
3) tighten lower intake manifold bolts. It's fairly common for these to come loose and allow a small leak through the gasket.
Those seem to take care of about 80-90% of people's trouble with spark knock on these engines.
I can't remember how much information was there, but check out www.glue.umd.edu/~singletn/exp.html for further instructions.

 

Some of the above items have info in the Ranger forum in the sticky called tech info. There is a TSB addressing decarboning. I've posted the contents of the TSB; it has recently resurfaced in the Ranger forum and should be easy to find.

 

I'm about to give up on solving the mystery of the engine knocking on my 94 Ranger with the 4.0...I followed the decarbon procedure with the PM-3 recommended...I changed out the plugs with factory specified double platinums with appropriate heat rating and gapped them at .54...I changed out the oil and filter...I flushed and filled the coolant...I carefully checked the vacuum system hoses and tightened all connections with clamps or strips....and I'm still getting the same knocking, $55 later...also cleaned MAF that showed no signs of carbon or dust...also...

Very frustrasted...should I give up..

 

Did you tighten the lower intake manifold? That cured my pinging.

 

Can You Give Any Details On That Procedure...?...i'm Not Sure Where That Is Located Or What Is Involved...the Book I Have Is Limited In Details...

 

Lower intake is underneath the upper intake manifold and fuel rail, between the valve covers. Chiltons discusses the intake manifold in the engine rebuild section, and covers both manifolds together. Haynes is the same way, I believe. If you don't have an adequate manual, try the vehicle repair guides at www.autozone.com, which is the equivalent of Chiltons.

 

I Tightened The Lower Manifold And No Change In The Pinging...