On this 1995 throttle-body truck, disconnect the tan/black spark-advance wire (between the ductwork and the blower motor below the glove box; it may be taped into the harness) and set base timing to 0 degrees. If the engine is actually CPI rather than throttle-body, timing is not adjustable: install the distributor at TDC on cylinder 1 aligned to the cap firing position. The coil test was not answered.
The owner of a 1995 truck with a newly installed engine and transmission asked how to set ignition timing and how to test the coil, recalling that older trucks required unplugging a connector behind the glove box or on the firewall and setting timing to 0. One reply said a 1995 should be CPI with no timing adjustment, only distributor alignment at TDC for cylinder 1, and that being far off can set a cam/crank correlation code. The owner said it is throttle-body injection, reported pinging when timed for best running, weak power at 0 degrees, a lean reading, replaced the knock and oxygen sensors, and described timing moving from about 18 degrees at idle to about -2 under heavy throttle plus highway hesitation. They later reported the fix: unplug the tan/black spark-advance wire under the glove box and set timing to 0. The coil question was not answered.
