C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Engine Wiring Problems '85

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Old Aug 1, 2013 | 05:14 PM
  #1  
Chuck Norris's Avatar
Chuck Norris
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Default Engine Wiring Problems '85

There are a lot of wires cut in my engine bay and i am having trouble figuring out where certain sensors are directed. If someone could give me some colors of wires or locations or pictures it would be much appreciated

Knock Sensor
MAT Sensor
02 Sensor
EGR Solenoid and EGR itself
Tach Wire on Distributor
AC Control
Both Temperature Sensors

I believe that was all that i couldn't figure out. Much thanks for everybody that can give me advice.
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Old Aug 1, 2013 | 07:24 PM
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Originally Posted by Chuck Norris
There are a lot of wires cut in my engine bay .
Time for you to buy the factory service manual for your car ( or the Cd version at least).
Will pay for itself in no time,
if you have cut wires then highly likely you will have other problem requiring the info in the FSM

KS is in the block in front of starter
MAT is under the plenum
O2 is in drv side exhaust pipe
Egr valve is on the intake manifold under the ( center ) plenum , EGR solenoid (for '85 ) at rear of intake ,pass side
Tacho terminal is marked TACH on the dist cap
Temp gauge( 1 wire ) sender in drv side head (for '85 )


CTS ( 2 wire ) for the computer is at front of intake


Last edited by vetteoz; Aug 1, 2013 at 07:33 PM.
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Old Aug 1, 2013 | 11:00 PM
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Thanks vetteoz, i have all the sensors in now in the right place now. i do have the service manual and have been using that as reference. the problem i am having now is which wires goes to the sensors.
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Old Aug 2, 2013 | 01:53 AM
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went and looked at my 85 and this is what i see..

ks= blue wire and goes to the esc module pin e
mat= a tan wire and blk wire
o2 sensor= blk wire
egr temp switch in the egr=green wire by the firewall then goes into a connector like the one you unhook for timing then blk wire to the egr temp sensor, as for the solinoid wiring not sure as mine is gone but if it mounts pass side rear of intake then its 2 wire plug pink/w blk stripe and light purple violet.
tach= white
1 wire temp sender in drivers head for guage= lol forgot to look
1 wire temp sender in pass head for the aux fan= blk
cts= yellow and blk or could be super dark blue, hard to tell

these are the colors on mine as best as i can tell, manual would be better imo but i have seen some that are wrong color.. always best then to trace the wires out .
best of luck
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Old Aug 2, 2013 | 02:09 AM
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Look in section 8A in the back of the FSM. There is an index in the front of that section. It shows all the electrical connections with wire colors.
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Old Aug 2, 2013 | 03:49 AM
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Thanks to all, I'll hopefully have all wires connected tomorrow
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Old Aug 2, 2013 | 04:05 AM
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If you've got the connectors a "quick reference" to the correct cavity and wire color EFI connection is generally very accurate. Just pick the connector you're interested in a click "details" - cavity and colors are there. If this link doesn't take you directly to the TPI section use the index on the left.

Looks like you just need to use the drop-down and select TPI from the link:

http://www.eficonnection.com/eficonn...ngineType.aspx
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Old Aug 2, 2013 | 05:21 AM
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http://www.chevythunder.com/1985_tpi_ecm.htm

http://www.chevythunder.com/fuel%20i...***********ECM PINOUTS
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