ignition question

[PunkChild]

I have a friend who is a mechanic and he also owns a prototype Explorer. He told me today about a switch or jumper on the back of the battery on 4.0's that retards the timing, allowing you to use premium fuel. Does this switch/jumper exist and if it does, would it increase performance?

 

[SteveVB]

Octane Bar

What year model are you talking about? Yes this jumper exists on the early models , all you have to do is remove the plug, its behind the pass. headlight.

BUT.. it does not increase performance, it should decrease the performance. It will retard the timing( I dont know from what to what, but I think I rermember reading that it takes 6 degrees total out ) which will decrease the performance. It is referred to as an octane shorting bar, and I think it is used when the gas avail isnt the correct octane. It will prevent you from having to use premium fuel. Ill look for some more info, but if its performance your after retarding the timing wont get it for you.

Oh yea, if the bar was previously removed then reinstalling it could give you some power back. I think the vehicles were shipped with the bar in place, so it should be there.

 

[PunkChild]

Thanks for the info.

 

[flyguy]

true true... wouldnt you want to increase the timing for premium fuel?

nick