Looking for temperature switch information

[saadow]

Hey guys, new to the forum. Little back story: in 2009, I purchased my first car. 1996 toyota camry, 5SFE 4 cylinder. I love my car, I don't want to give up on it, but I've had such a staccato of problems that it's throwing me for a loop.

Last winter, towards the end of it, the car was displaying some trouble running, it'd stall out on me while stopped or idling at intersections. Took apart the EGR valve, cleaned it out, it was packed with carbons solid. A week later, similar problems were occurring. My father was a mechanic for over twenty years, so we looked at the fuel filter, and it looked like it was never changed. So I bought a new filter, he helped me put it on, car sounded great for a couple of days. At this point, it'd start running rough after a few miles of driving, then it'd want to quit out. You park it and the RPMs'd spike up to 2k, then way low to almost 500, then eventually just die on me there. We discovered a problem with the wiring harness for the igniter, namely some of the wires were coming out of it, and most of the harness was held together with 3+ solderless terminal ends per wire. Lovely right? Now, the mechanic shop fixed this, but there was still a problem with it wanting to die out on me, so I took itr back to the mechanic I bought it from, he opened up the IAC, as well as cleaned the TPS. The IAC was a mess, according to the mechanic, so that was cleaned out. Now, the vehicle is running great when it gets there or starts cold. But, if I drive a couple of blocks, then go into the store, sometimes, the car will not want to start when I get back to it. It'll crank, it's got spark and fuel, but it just won't ignite. If the car has sat for a while and it's cold, it'll start okay. This seems to be a reproducable problem, and my father has it in his head that it's the Temperature Switch.

Now, my question, is what the Temperature Switch might have to do with this, and what temperature switches (I've heard there are multiple) should I check, and where can I locate them?

Any help and ideas would be appreciated.

[TrailDust]

Hi there, welcome to Toyota Nation!

I edited your thread title to reflect the type of information you're seeking. Also, you'll want to use the forum's search feature to locate past threads that may address your temperature switch issue. Thanks!

[dc_98_cam]

wild guess ....
Does this engine use a distributor ..... is there a distributor cap that the spark plug wires are inserted into?
If so, then there might be corrosion of some sort on the interior of the cap, where the metal high voltage spark electrodes are located. The symptoms that you describe are exactly like what used to happen on a lot of early GM distributor caps.
To fix, just get a new cap and center piece for the distributor. Get the best quality you can .... the high voltage of the spark tends to build up a layer of oxide, which inhibits electrical conduction. .... also complicated by thermal/heating of the conductors.

[Mike Gerber]

The temperature switch you are looking for is called the engine coolant temperature sensor. It feeds information to the main computer as to what the temperature of the engine is (based on coolant temperature) and the computer adjusts the fuel mixture based on this information. In some of their manuals Toyota refers to it as the ECT sensor. If you are standing in front of the engine it is located to the right (driver's side) of the cylinder head on a port to that side of the cylinder head. There are 2 or 3 sensors there. The one you want is the one under a green plastic connector. It is a 2-prong sensor that screws in to that port. You can check that sensor at various engine temperatures with a digital volt/ohmeter and the specs from any manual. They are about $30-$35 to replace, using an aftemarket sensor.

Another thought would be your coil inside the distributor is causing the problem with the hot engine. They have a tendancy to cause problems like you describe when they rack up lot's of miles. You can also check the coil for being in spec with the DVM and the specs from the same manual. Also, remove the coil from the distributor and inspect it carefully for hairline cracks. Cracks in the coil shorting to ground inside the distributor on a hot engine is another common problem on the first 3 generations of Camry. An aftermarket coil is around $50.

Mike

[hill8570]

Quick check for that temp sensor that Mike mentioned is to just disconnect it when you're getting the problem -- the fail-safe for that sensor is to default to "warmed up" -- if it's the sensor you'll suddenly be able to start. You'll get a CEL, but it'll go away as soon as you re-connect the sensor.