This past weekend my 88 died in the parking lot, cause of no spark. replaced the TFI module under the distributor, still wouldn't start, bought a new pick up / hall sensor, accidentaly cracked the distributor gear as I was reinstalling it I'll pick up a new one tomorrow.

While I was pouring through the Ford service manuals looking for the cause of my problems the manual described the "Octane Bar" which is set up for the correct octane for the gasoline used. Well I remember back in 88 the gas had a higher octane rating than it does now. The octane bar that is installed in my distribor has a "0" stamped into it twice. inside and out.

Does anybody have any info about these octane bars? Are there different choices that can be installed? this bar holds the hall sensor at a certain place in the distributor and I would think longer bars or shorter bars would effect the overall timing of the spark.

 

One would have to assume that the newer the bar the lower the octane it was designed to run. Since octane ratings haven't gone UP in ages, I would think you could swap a newer unit into an older distributor. The bar is basically setting the duration that the magnet in the hall sensor remains engaged/disengaged. The stronger the magnetic field the quicker the make and slower the break in the sensor. This would increase spark duration which would affect burn capacity and could easily be "adjusted" for variances in octane by changing the size and/or density of the ferrous bar that the magnet reacts to. I would have to look at a PIP sensor again to refresh my memory though.

 

there are two parts to the Hall sensor, the first is the coil / electronics of the sensor where the igntion module plugs in, and the second part that the octane bar attaches to is the make/break part that senses the gaps in the brass cup under the rotor. the octane bar if it is longer or shorter will adjust only the make / break portion, which will only change at which degree the gaps are sensed.

 

Some late night reading if you care to find the cure for insomnia: https://www.ford-trucks.com/forums/9...tment-rod.html

 

The octane bar was a way for Ford to appease the EPA-At the dealership we where not allowed to loosen the Dist to adjust the timing, we had to retard or advance the timing with an octane bar and the warranty ticket MUST have an octane bar part number on it if you turned a claim in for timing adjustment AH YES I remember the good old days Ford Tech Jan. 1977 to Nov 2008 Regards Blue