Nicnic100

I'm heading to a junk yard soon to see if I can get lucky and I read one of the things you should have your eye out for is sensors. Extra sensors are always good to have. My question is what the heck is a sensor? Also where could I find these sensors. Oh and if you have any otherideas of things to look for at the junk yard, please share. Thanks.

89Laredo

You want pretty much anything you can find,
IAC (on throttle body, 1" round stepper motor)
TPS (throttle pos. Sensor, on throttle body)
NSS (Neutral Safety Switch, on passenger side of trans. junkyard may charge you a bit for it though)
CTS (coolant Temp Sensor, in rear of block)
IAT (Intake Air Temp, Located in intake manifold towards rear. 19mm wrench to get it out)
CPS (Crank Position Sensor, On bellhousing top)
CKP (Cam Pos Sensor, inside distributor. Or you can just pull the whole thing)
etc.

guest02

Here is a great link for information about sensors...

http://www.aa1car.com/library/1999/cm69910.htm


Hope this helps!

5-90

A "sensor" is a device used to monitor a condition - whether it is a changing condition, or a condition that could change but should not. The conditions most commonly monitored are temperature and pressure, but nearly anything can be monitored (rotational speed, synchronisation of two shafts, ...)

That answers the "what." "Where" depends on the sensor you're looking for:

- Oil pressure sensor is down by the distributor. Two types.
- Coolant temperature sensor may be at the driver's side rear corner of the cylinder head (to 1999,) down on the driver's side of the block (to at least 1995,) and could be in the thermostat housing (1991 forward.) 1987-1990 also has a "sensor" as a thermal switch in the driver's side radiator tank, used to turn the electric auxiliary fan on and off.
- Manifold absolute pressure will be on the firewall (early) or on the throttle body proper (late.) A remote MAP sensor will have a line leading to the throttle body.
- Manifold temperature will be monitored by a sensor screwed into the manifold proper.
- Crankshaft speed will be monitored by a sensor located, if you were to look from the back of the engine forward, at 11:00 on the bellhousing. Definitely get all of the screws for those you can - they're special.
- The camshaft/SYNC sensor will be located inside the distributor. Disassembly of the distributor is required for removal.
- The IAC (Idle Air Controller) isn't so much a "sensor" as an "actuator" - a sensor generates an input for the ECU to read, an actuator responds to an output from the ECU. The description is otherwise correct.

I am inclined to think there may be some more sensors, but they're escaping notice for the moment.

NB: Some sensors (the oil pressure sensor, the temperature sensor at the rear of the cylinder head) will come in two types - one to drive a panel lamp (gives a simple ON/OFF value) and one to drive a panel gage (gives a variable resistance, which is used to generate a variable voltage signal.) The lamp type will sort of work with a gage (it will result in full swing to one side or the other, depending on whether the switch will be ON or OFF,) but the gage type will not drive a lamp. Check the instrument panel to see which sort you can expect.

In OBD-II vehicles (1996-up,) all sensors will give with variable resistance/variable voltage signals, and any lamps will be driven by the ECU (just as the gages will be.)

Response curves for temperature sensors are fairly standard (answering back to values for General Motors "thermistor" type sensors,) and there is a good deal of crossing over you can work with. The primary difference will be the plug used to connect to the vehicle harness.