cold engine ? and ect sensor index

[DDSTANG94]

does the ECT sensor need to be indexed or put in a certain amount?

also what can cause poor performance when the motor is cold, here is what has been replaced

ECT
O2's
tune up

what eles could cuase problems? the problems im experiencing are at low rpms when the motor is cold it feels like the timming is retarded and skips a little bit, then when it hits like 3k it comes alive and starts pulling harder, like i said it does it when its cold out and the motor is cold

 

[DDSTANG94]

common guys ??

 

[cjones]

IAT (Intake Air Temp) - if that shows warm air coming in then it could cause problems. when you replaced the ECT you replaced the coolant sensor with 2 wires, right??

have you run codes??

 

[DDSTANG94]

IAT (Intake Air Temp) - if that shows warm air coming in then it could cause problems. when you replaced the ECT you replaced the coolant sensor with 2 wires, right??

have you run codes??

ok is the IAT different from the ACT? when i replacet the ect i only did the one that treads in the intake fitting.....and yes but no codes came up

 

[HISSIN50]

IAT and ACT perform the same function. They both measure the temp of the intake charge. Fox III's (with intake mounted sensors) generally are called ACT's. Cars with the sensor in the air inlet tract seem to be called IAT.

The ECT is the coolant sensor for the EEC.

You dont index an ECT.

You dont have to index an IAT but I do (I put the support posts at 12 and 6 o'clock so nothing blocks the bulb).

 

[DDSTANG94]

IAT and ACT perform the same function. They both measure the temp of the intake charge. Fox III's (with intake mounted sensors) generally are called ACT's. Cars with the sensor in the air inlet tract seem to be called IAT.

The ECT is the coolant sensor for the EEC.

You dont index an ECT.

You dont have to index an IAT but I do (I put the support posts at 12 and 6 o'clock so nothing blocks the bulb).

ok thanks, any thoughts on what my problem could be?

 

[HISSIN50]

Have you checked codes and the calibration of the ECT?

 

[toyman]

From reading the posts I don't get a clear picture that the OP knows where the ECT is located. It appears that he's confusing it with the IAT (ACT). The ECT is located on the passenger side lower intake manifold and has a two wire connector. The coolant sensor on the driver's is the one for the dash gauge and has a single wire.

 

[DDSTANG94]

Have you checked codes and the calibration of the ECT?

no codes, the ect is brand new motorcrafter

 

[HISSIN50]

Being new doesnt mean good, nor does it mean the sensor is calibrated. You just gotta test it (I would ohm out a new sensor before installing it, just for the sake of doing so). With it on the car, I'd check the signal reading instead - since that takes the voltage to the sensor into account.

 

[DDSTANG94]

Being new doesnt mean good, nor does it mean the sensor is calibrated. You just gotta test it (I would ohm out a new sensor before installing it, just for the sake of doing so). With it on the car, I'd check the signal reading instead - since that takes the voltage to the sensor into account.

iv had two new ect's on there, how exactly do i check it

 

[HISSIN50]

The IAT is scaled the same as the ECT.

ECT values

 

[Bullitt95]

IAT sensor = Intake Air Temperature sensor = ACT sensor = Air Charge Temperature sensor (located in airpipe between MAF and TB)
ECT sensor = Engine Coolant Temperature sensor (located on passenger side of intake manifold, screwed into heater tube assembly and has 2-wire connector)
Coolant temp. gauge sending unit is located on the driver's side of the intake manifold and has a single-wire connector.

The engine needs a richer A/F mixture and more timing advance when it's cold, so the ACT and ECT sensors are very important during the engine warm-up phase. If there's a short in the wiring to either of them (or a short inside the sensor itself), the voltage across the sensor wires will be near to zero volts (too low) and the engine computer will think that the engine's hot, retarding the timing and leaning out the A/F mixture causing cold driveability problems. I suspect your problem lies there. A short in the ECT sensor wiring will usually cause the electric fan to stay on constantly while the engine's running.
If either of the sensors themselves goes bad, the result is usually the opposite (voltage across the sensor wires near 5.0v reference, engine runs rich but otherwise pretty well during the warm-up phase).

 

[HISSIN50]

IIRC, as IAT and ECT values increase (towards VREF), the indicated temperature is lower, not higher.

 

[Bullitt95]

You're quite right Hissin. Thanks. I've corrected my last post.

 

[DDSTANG94]

so is it possibly it is the IAT or more likely the ect

 

[HISSIN50]

so is it possibly it is the IAT or more likely the ect

The ECT is more important IMHO.

But test both. It will take just a minute to test each. I do them at room temp and then at operating temp. Those are two critical temps and are spread wide apart. If both are copacetic, I can assume any interpolations or extrapolations will be copacetic.

 

[DDSTANG94]

The IAT is scaled the same as the ECT.

ECT values

ok so i tested the ECT at room temp in my house, about 70*. I put the meter at 200k ohms and got 22.7X so my sensor is no good? what should it read at that temp..did i do it write??

 

[HISSIN50]

Seems a little off. It should have read somewhere near 38K Ohms. Was the bulb sitting in water that was room temp? I dont test the sensors in free air so I'm not sure if that could affect it.

 

[DDSTANG94]

Seems a little off. It should have read somewhere near 38K Ohms. Was the bulb sitting in water that was room temp? I dont test the sensors in free air so I'm not sure if that could affect it.

no i tested it in the air, should i put it in water