1998 3.9 looking for timing info.
suspect chain jump due to zero compression in all 6 cyclinders .
I've taken off timing cover dots don't align regardless of how many rotations of
the gears make I end up with with both dots pointing at 12 to be at #1 on the rotor ,when dots align rotor points at #4.
I've been looking on net for info on how but have only been finding replacement of....

 

Actually, that's correct..... What is your 3.9 in?

 

Its in a 1500 van .Thanks for the answer to that
question.
so would you have a thought on why there is no compression in any cyclinders..thanks

 

First think I would think is broken timing chain, but, that doesn't appear to be the case...... That it is affecting ALL cylinders is a puzzler too..... I just can't see one or more valves in every cylinder failing all at the same time....... Highly unlikely. Can you do a leakdown test? See where the pressure is going? (requires an air compressor, and a gauge set.)

 

I talked to a mechanic is why i thought it was the timing .
I've used compressed air and it sounds like it's coming out the exhaust. I moved the crank back in forth while doing this and it changed the amount of air coming out but never stopped completely.

 

On all cylinders? Or just one??

 

No I don't think so unless there are 2 dots on one of the gears. The camshaft gear dot should be at 6:00 when the crankshaft gear dot is at 12:00.

To further verify if it's a timing issue, remove the #1 spark plug and valve cover. Then slip something rod shaped about 8" long into the spark plug hole. Slowly turn the engine while watching the rod move up. Once you feel the #1 piston is at or near TDC check to see if the two valve rockers for #1 are down and the rotor is pointing at the #1 cap tower. If they are then the valve timing is good.

 

The crank turns twice for each revolution of the cam. Timing sets are generally installed 'dot to dot' as shown in the illustration there, but, that puts the firing order in the MIDDLE, NOT at #1. Turn the crank once, and no both dots are at 12, THAT should have #1 in firing position.