91 vette

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Dec 25, 2003 | 10:10 AM

6spd

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Burning Brakes

Joined: Jun 2003

Posts: 949

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From: smithtown ny

91 vette

took the vette for a ride today and when i got home i looked at my ez link scanner and the knock senser was at 18 what causes that??

Dec 25, 2003 | 10:23 AM

65Z01

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Joined: Dec 2000

Posts: 90,675

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From: SE NY

Cruise-In II Veteran

Re: 91 vette (6spd)

Once after each startup the ECM advances timing till it gets a knock count, to test the knock sensor. This is one reason that the knock counts gradually increase.

In addition knock counts can be caused by a bad knock sensor, by metal rattling near or against the block , by low octane fuel and by too much base timing.

If possible monitor knock counts while driving to see if they increase after a WOT burst for example.

Dec 25, 2003 | 10:36 AM

6spd

Thread Starter

Burning Brakes

Joined: Jun 2003

Posts: 949

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From: smithtown ny

Re: 91 vette (65Z01)

hi, what's weird about this is the knock senser is new i use 93 octane and i didn't see any knock retard?

Dec 25, 2003 | 10:38 AM

6spd

Thread Starter

Burning Brakes

Joined: Jun 2003

Posts: 949

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From: smithtown ny

Re: 91 vette (65Z01)

i forgot to mention that my timing is set to 6btdc

Dec 25, 2003 | 11:31 AM

65Z01

Team Owner

Joined: Dec 2000

Posts: 90,675

Likes: 304

From: SE NY

Cruise-In II Veteran

Re: 91 vette (6spd)

So, it may just be normal operation of the system.

Take a scan, take the car out for a short drive, shut off and take another scan.

If the knock count increased by more than one count, go out again, do a WOT burst through the 1-2 shift, shut down and take another scan.

If a jump in knock counts, time to trouble shoot it; else, no problem.