octane adjust plug

WAIT A MINUTE!

HOLD UP EVERYBODY! Don't unplug the octane adjust connector!!!! Unplugging it causes the car to run less timing, not more as I had thought! I did some reading in my books and came across this in my "How to Understand, Service, and Modify Ford Fuel Injection and Electronic Engine Control 1988-1993" by Charles Probst:

"The Octane Switch in some engines adds a feed-foreward signal for spark timing and turbo boost. When the Octane Switch is in place in the underhood socket, it shorts the contacts in a circuit to the control module for normal spark timing. If the engine is knocking with the fuel being used, you can change to a higher octane fuel, or you can remove the switch from the socket to retard the timing by about 3 degrees, and reduce maximum boost."

"Fig.9-1. Octane Switch shorting bar closes a circuit to control module providing normal spark advance for fuels of recommended octane. Removing shorting bar signals control module to retard spark about 3 degrees to handle fuels of lower octane."

So the long and short of it is that if you remove the octane adjust plug, you lose power and fuel economy!

juggalo said:

that's what i'm goin for

Click to expand...

Re aggressive timing, I once made the mistake of putting on my damper bolt without using an air-tool. Many months down the road and unbeknownst to me, the bolt began to back-off. This allowed enough play between the damper and crankshaft, to allow for some wobble. For quite some time I noticed a HUGE boost in power. (note: took place during warm weather months) Eventually I started experiencing a HUGE power loss, but only on a cold start... then resumed with the huge power boost. Still eventually, the engine got harder and harder to run on a cold start until it got to the point that it would stall unless you baby-sat the accelerator. Not soon after, I had no power at all. Literally had to run 4000RPM just to get it a very slight incline.

Longer story short and after several hours of troubleshooting, I happened to notice the damper wobbling on it's axis while running.

Once pulled, I had discoverd that the damper key, (in the crankshaft,) had carved a ~10 to 35 degree notch in the damper. So I had to get a new damper.

But, the key observation here, is that modifying your damper keying, may have the potential to advance your timing. To note, the damper did rock back and forth on the crankshaft, in response to resistances produced by the serpentine belt items. I have no idea what kind of impact that may have had on the overall timing.