I was changing the plugs and wires on my '89 Formula and I found this just hanging there. It was underneath on the passenger side by the starter. What is it and where does it go?

 

Knock Sensor, looks like it's either unplugged, or broken sensor, hard to tell. Have fun changing it, frame is in the way and if it's seized at all it's a nightmare.

To second question, down by the starter, on the block about 3-4 inches towards the front of the car by the starter.

 

It's not hard to get to. You just have to jack the car up and go under it. It's in block just above front of the starter. It does loo like the connector of the sensor is broken off. Any pinging of the engine or code 43?

 

Thanks for the quick response.

Yeah it's definetly broken. There were pieces cracking as I moved it out of the way. Should I assume my car is not going to run (or run really bad) until I replace it?

 

No codes or pinging.

 

Is your car still stock use the computer? Usually under accelation if there is knock the sensor will tell the computer and it will retard the timing. With it not hooked up it can't and would usually set the cel.

 

I went back outside to look and take more pics. Isn't that the knock sensor plugged in. I included that broken connector in the picture as well.

Thanks.

 

My computer is stock... as far as I know. What did you mean "set the cel"?

 

Here is the picture.

 

cel= Check Engine Light

I don't see the new pics you are talking about.

 

Ok yes that IS your knock sensor. I looked closer at the first pic, and that looks to be the fan switch. Are the plugs it is in between 6 and 8? How is your radiator fan working or not working?

 

Got it. Check Engine Light. Thanks. Still learning. Yes the plug is between cylinders 6 and 8. The fan works fine.

 

Is the fan wired to be on constant or to an aftermarket switch that you know of? Because with the fan switch broken, the fan should not turn on normally and you would overheat.

 

It is on as long as the key is turned on.

 

ok ive had that same plug loose near my dizzy for months now not hooked up and never really thought about it. can you take a pic and show me where it goes please

 

That doesnt surprise me, the fan switch breaks and comes loose, then the previous owner just grounded out the fan relay so it runs as long as the key is on. Its pretty common.

 

If you get under the car, and look up at the bottom of the block on the passenger side you'll see a round thing about the diameter of a quarter. That would be your fan switch.

 

i thought that was the knock sensor by the starter

 

It may be, I think they look the same and I get them confused.

 

According to the diagram I have for an LO3, both the knock sensor and fan switch are on the passenger side. The knock sensor is at the bottom of the block, just forward of the starter. The fan switch is towards the rear of the block a just below the head.

 

Thanks for all of the input.

 

The fan switch is on the left, and knock sensor on right. The connectors are similar, a single wire. A little off topic......what is the turn on temp of the stock fan switch on an L03 single fan?

 

212F or 226f not sure which one