Octane Bar?

[beavis195]

Looking through records and came upon when we moved here and were getting the last services out of extended warranty at 75,000 miles. It says, Customer states that engine makes a clattering noise on acceleration uphill. Stops when let off gas. Verified concern found to have octane bar installed pulled and noise is gone now. What does an octane bar do? I remember the regular unleaded gas in Utah where I used to live was 85 octane, and here it is 87. Does the octane bar have anything to do with the High Altitude question I asked here: http://www.explorerforum.com/forums/showthread.php?threadid=32964
Thanks

 

[Rhett]

Maybe they mean the Octane Shorting Block...which if pulled will most likely stop pinging but will also cause your truck to have even less power. The mechanics that worked on your truck were not too creative. Pulling the octane shorting block is a poor solution to the problem.

 

[SteveVB]

octane bar info

Octane bar or switch as some call it retards the timing by about 3 degrees when the bar is removed- normal timing when its in place. I agree its a poor solution to the problem but can be used as a last resort. If everything checked OK then I would probably run a bit higher octane 87-89 see if that would help.

Info I have from Charles Probsts EEC book says it was originally installed on Cali emmission 2.3 turbo cars when it was determined they needed to be able to run on reg fuel for regulatory reasons - this after the engine was built and tuned for premium fuel. Ford added the shorting circuit and removed the bars when they needed. The circuit is/was obviously used in other vehicles with the eec controls
FWIW

 

[beavis195]

so is it a switch I can just flip back? I mean, this thing is already slow enough. I'd rather put up with engine pinging when I go uphill than a poor performing truck.
Thanks for your help.

 

[beavis195]

bump

 

[Rhett]

You don't want pinging no matter what--it will damage your engine over the long run.

If I were you I would run whatever octane it took to stop the pinging...WITH the octane shorting block installed...rather than have no power without the block installed. If you can't even run premium gas without pinging then there is something wrong with the truck. Even my Explorer, which is prone to pinging on 87 octane, is quiet if I put mid-grade gas in it (89 octane).

in other words I would not want to run my truck with pinging, it's hard on the motor.