ECM-timing Question??

[TampaTom]

I have a 1997 CVPI. Does this 4.6L ECM have an "anti-knock" sensor? When using 87-octane gas, the car seems to have less acceleration (w/no knocking) than it does with 89/93-octane. Is the ignition-timing automatically adjusted?
Since I have no knowledge of electronic engine-controls, any info. is appreciated.

[ModMech]

Nope, your car does NOT have a knock sensor. The most likely reason for the performance difference you see is that if the engine knocks, and most often you cannot hear it, you lose power hence you lose acceleration.

[TampaTom]

Originally Posted by ModMech

Nope, your car does NOT have a knock sensor. The most likely reason for the performance difference you see is that if the engine knocks, and most often you cannot hear it, you lose power hence you lose acceleration.

Thanks, Modmech---Do you recomend 89 octane for this engine? Of course, 87 is less expensive if it is OK......Tom

[ModMech]

Use the grade of fuel your car runs best with. For most people, that will be 87-90 octane, and it can very by suppier and time of year.