Welcome to the Corvette Forums at the Corvette Action Center!

DETONATION SENSOR

chevyagain

Well-known member
Joined
May 13, 2007
Messages
77
Location
VIRGINIA
Corvette
1984
does anyone know the function of the ESC detonation sensor
on a 84 crossfire, while under car i noticed it was disconnected
sort of a round switch, forward of starter in block. if this is not
working what does it do to engine performance
 

wishuwerehere82

Well-known member
Joined
Sep 6, 2003
Messages
2,314
Location
Rochester, NY
Corvette
Red '82 Coupe,Sebring Silver '98 Coupe
The function of the knock sensor is to retard the ignition advance in case of sensing engine knock.
If you don't have any knock, it doesn't do anything.
I assume your timing is set low enough, and your octane rating is high enough that you're not getting any knock.
This may have been disconnected because of a bad sensor. If they go bad, they will randomly retard the timing, causing the ignition advance to be all over the place.

If it is reconnected, you can test it with a timing light and a hammer. Connect the timing light to #1 plug and observe the timing mark on the harmonic balancer. Then whack the block with the hammer, and the timing should retard.
You may be able to get more performance with it re-connected, and properly timed.
 

KANE

Moderator
Joined
Mar 2, 2002
Messages
3,244
Location
KY
Corvette
Dark Blue 1982 Trans Am(s): Polo Green 1995 MN6
does anyone know the function of the ESC detonation sensor
on a 84 crossfire, while under car i noticed it was disconnected
sort of a round switch, forward of starter in block. if this is not
working what does it do to engine performance

You have a speed-desnisty system... so, that will do plenty. Have you noticed- was the check engine light illuminated?

The ECM cannot advance or retard the spark without the knock sensor. Hook it up- disconnect the battery, and then see if the light goes out (it should).
 

chevyagain

Well-known member
Joined
May 13, 2007
Messages
77
Location
VIRGINIA
Corvette
1984
The function of the knock sensor is to retard the ignition advance in case of sensing engine knock.
If you don't have any knock, it doesn't do anything.
I assume your timing is set low enough, and your octane rating is high enough that you're not getting any knock.
This may have been disconnected because of a bad sensor. If they go bad, they will randomly retard the timing, causing the ignition advance to be all over the place.

If it is reconnected, you can test it with a timing light and a hammer. Connect the timing light to #1 plug and observe the timing mark on the harmonic balancer. Then whack the block with the hammer, and the timing should retard.
You may be able to get more performance with it re-connected, and properly timed.

thanks for your help, i think this is why i was having alot of trouble
with running poorly, let you know how i make out
 

chevyagain

Well-known member
Joined
May 13, 2007
Messages
77
Location
VIRGINIA
Corvette
1984
thanks for your help, i think this is why i was having alot of trouble
with running poorly, let you know how i make out

do you happen to know what color wire goes to the knock sensor my wires
are not in good shape and i dont have a manual as of yet
 

chevyagain

Well-known member
Joined
May 13, 2007
Messages
77
Location
VIRGINIA
Corvette
1984
thanks again, the wire that looks like it goes is green cause it has the pin type connector. my wires going to the solenoid are frayd ang in bad shape
i have a tan wire or brown coming out of that harness that should go to the coolant sensor but ill check again and get my books
thanks again for your time-----john
 

wishuwerehere82

Well-known member
Joined
Sep 6, 2003
Messages
2,314
Location
Rochester, NY
Corvette
Red '82 Coupe,Sebring Silver '98 Coupe
The ESC knock sensor has a weird connector. It's like a Metal spring clamp that you squeeze together to fit over the post on the knock sensor.
 

chevyagain

Well-known member
Joined
May 13, 2007
Messages
77
Location
VIRGINIA
Corvette
1984
The ESC knock sensor has a weird connector. It's like a Metal spring clamp that you squeeze together to fit over the post on the knock sensor.

would like to replace all connectors as original, my are disintergrated
do you know somewhere that has em, i guess i could make my own
as long as it gets juice. im originally from long island now in va.
noticed your in rochester. havent gone to any parts stores yet
to check on connectors, kinda in the woods here------------john
 

chevyagain

Well-known member
Joined
May 13, 2007
Messages
77
Location
VIRGINIA
Corvette
1984

jmccloud

Well-known member
Joined
Feb 1, 2003
Messages
694
Location
Maryland
Corvette
1995 White Coupe LT-1 Auto
Removing knock sensor

My '95 had one 'rounded' knock sensor. No way a wrench would grasp the hex because it was 'well turned' by a previous owner. A LARGE set of water pump pliers (channel locks) about 15" long unscrewed the sensor very easily. New one was only about $20.
Good luck
 

chevyagain

Well-known member
Joined
May 13, 2007
Messages
77
Location
VIRGINIA
Corvette
1984
My '95 had one 'rounded' knock sensor. No way a wrench would grasp the hex because it was 'well turned' by a previous owner. A LARGE set of water pump pliers (channel locks) about 15" long unscrewed the sensor very easily. New one was only about $20.
Good luck

thanks, finally got it, drpped starter, used of all things, a basin wrench
worked great------------------------------john
 

c4c5specialist

Technical Advisor
Joined
May 29, 2001
Messages
3,682
Location
New Haven, Ct. USA
Corvette
Nope, but someday.
HI there,
Make sure you only tighten the sensor to 14 ft lbs.
Any tighter, and you will create a lower power condition.
And do NOT use any sealant.
Allthebest, c4c5
 

Corvette Forums

Not a member of the Corvette Action Center?  Join now!  It's free!

Help support the Corvette Action Center!

Supporting Vendors

Dealers:

MacMulkin Chevrolet - The Second Largest Corvette Dealer in the Country!

Parts/Accessories:

Vetteskins

Advertise with the Corvette Action Center!

Double Your Chances!

Partners

Top Bottom