you need to pull your timing belt set your cams to zero they have timing marks and crank your engine to tdc and put your timing belt back on make sure everthing is at zero or you will not be able to get your timing right by moving your distributer.
.031 in timing is 10 degrees BTDC at 800 rpm
The correct timing for that is 10'btdc. but you must short out diagnostics with a paper clip. The correct plugs to short and the timing is on a label located on the inside of your hood. you must short this out to get proper timing so the timing won't advance. i hope that helps. i have a 1990 4 runner as well.
There should be a sticker in the engine compartment that shows the specific information for your vehicle. If you don't have one then it has a normal setting of 10 degrees BTDC at 800 RPM
on the v6 bridge terminals te1 and e1 in the diagnosis control box under the hood and the timing should be 10 degrees btdc
My book says to check the emission label in the engine compartment. I have a 92 V6 and the label says 10 degrees BTDC at 800 RPM.
1 (0 deg BTDC) - 5 (480 deg BTDC) - 3 (240 deg BTDC) - 6 (600 deg BTDC) - 2 (120 deg BTDC) - 4 (360 deg BTDC)
10 btdc
The correct timing for a Mercruiser 3.0L 140 engine is 6 degrees BTDC. for a Mercruiser 120 the correct timing is 8 degree BTDC.
35 BTDC 35 BTDC
8º BTDC
6 cyl ------------------------> 4* btdc 8 cyl 2brl-------------------> 8* btdc 8 cyl 4brl -----------------> 12* btdc Straight out of my 71 pontiac factory service manual
10 degrees BTDC