Alright, so I just started reading into PROM for beginners and saw that the computer uses temperature readings to tell the computer when to learn or not and when to be in closed or open loop, well recently I've been having trouble getting my car started when it was cold out, I would have to manually adjust the idle screw which seems weird to me because the engine is run by computer. I was wondering that if a disconnected coolant temp sensor (the pass. side one) would cause the ecm not to learn and not adjust the choke when it is cold (roughly 40 degrees). The reason it is disconnected is because the PO broke the connector for it and so of course the wire will not stay in the sensor. Any ideas are greatly appreciated!

 

is that a 2 wire or 1 wire temp sensor?

 

It is a 1 wire.

 

There are switches and senders in the heads, the sensor is in the intake manifold.

Get all the basic tune up stuff 100% covered in detail. That will make all the difference in further troubleshooting.

 

As far as I know there is only one coolant temp sensor/switch in the passenger side head, which is a 1 wire, how much more detail is needed? pictures? part numbers? I just wanted to know if having it unplugged would cause the computer to be in a mode that wouldn't allow it to adjust properly to outside temperatures when it is less than 40 degrees.

 

The temperature sensor in the passenger side head is for the radiator fan. The temperature sensor in the drivers side head is for the dash gauge. Both of these are 1-wire sensors.

The two wire sensor in the front of the intake manifold is for the ECM.

RBob.

 

Got any ideas as to why the computer won't help my car idle when it's cold then?

 

I am a little confused by what you mean learn.. The car doesn't go into closed loop until a series of thing happens pending on what it programmed into the chip.. It goes into closed loop only after each item is satified by what the computer reads the appropriate numbers from each sensor, so it stays in open loop until then. I think if you start unplugging sensors, the computer will not see the numbers it is looking for at all. I hate guessing at sensor's also, but what you really need to do is get a computer with an ALDL connector and check out your readings in your computer to see what it see's.. That will help you diagnose what is going on with your system and not spend $$$ on guessing what is wrong

 

The computer wont make any adjustments until the car warms up. The problem isnt with your computer but is something else. I would start with basic tune up stuff and go from there. Check your TPS and also check your IAC

 

When my car had a map sensorfail it ran very lean. I have a WB. Not sure if you have a MAP sensor or are MAF. If it was cold out I bet my car would not have started.

Is your CE light functioning? any codes?

 

I am seeing a pattern of people stating the same thing...



Hopefully that is enough of a clue

 

It's a Map, I haven't tried to pull codes, CE light works and isn't on. I unplugged the map and the car ran the exact same though, and I've heard that when the map sensor is unplugged that the computer uses a factory setting for map, but considering I don't know what kind of crazy things POs have done to my car, my best bet would probably be getting a laptop and seeing what the ecm is seeing. I know certain things aren't hooked up (why they don't throw a light idk), and I've even found a socket on the underside of the engine that was there for god knows how many miles.