Can someone please give me a location (picture) for the coolant tempature sensor on a stock 1987 'vette 5.7 litre or give me the page in the service manual that shows it. I seem to have lost fast idle and simutaneously lowered gas milage. I have been told it is probably the temp sensor and that would cause both items. Any help will be appreciated.

Thanks

 

Well, since you wrote that "any" help would be appreciated, here's what I did. Since I use to own a 86 - not 87 - I looked in my 86 FSM and on page 6D5-1 I found a diagram of what GM calls a COOLANT TEMPERATURE SWITCH, which is what you're looking for.

Sorry I don't have a photo or a way way to post the diagram. Maybe someone else can cover that base for you.

The CTS is mounted to the front of the intake manifold, slightly to the passenger OUTBOARD side. There are two switches mount there, right next to each other.

The COOLANT TEMPERATURE SWITCH IS THE OUTBOARD ONE.

Now there is another switch screwed into the driver's side cylinder head which controls the fan operation. There's yet another one which is screwed into the passenger side cylinder head - in the area of #6 spark plug which is for the dash board coolant temperature gauge. Over the years, GM did swap the location of those two but I believe 86 and 87 are the same.

I'll bet Agent86 has more details on your question. I just offered what I believe to be correct since no one had chimed in.

Hope this helps.

Jake

 

Thank you for the response. I saw the switch on 6D5-1 but am not sure if that connects to the sensor (appears to be a nut behind it) or how to get it out since the female part of the switch is on it. (In the 87 manual it is the same page but shows it to be on the passenger side below the throttle body if I am looking at the right thing.) Again, Thank you for your response. I'll see if Agent 86 happens to pick up on this thread before I mess the car up too bad hunting. :-)

 

CTS circled
Unit with brass nut is switch for Cold Start Injector (CSI ); has same style connector as injectors

 

Interesting stuff.

Does the ECM command operation of the CSI? Or is the CSI / sensor independant? Just curious why two temp sensors.

 

CSI is independant of ECM. The CSI is turned on with the thermo time switch, it's duration is also controlled by the same switch.


There is another pic in section 8A-201-5

 

WOW!! MY BAD!!! I meant to write Passenger side. Nice catch; I already made the correction.

All you need is a deep-well six point socket to unscrew it from the intake. IIRC is takes a 3/4" socket.

Jake

 

I don't know what engine this intake setup came from. Whether it's off a 'F' body or a different year 'Y' body.

The 86 Vette has it's fuel lines directed to the Passenger side of the engine.

Jake

 

Thanks for the help guys. I'll see where it goes from here.