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Engine miss

Tiny
TOBYJAY
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Will do as you suggest. There's an Autozone in a community 30 miles
away and I should be able to get there within a few days. If that doesn't pan out I will pursue the module under the drivers side dash.
Exactly what is the B cavity?
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Wednesday, March 16th, 2011 AT 11:31 PM
Tiny
SATURNTECH9
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I posted a diagram that show's the connector and all the cavity's are labeled I also posted how to flash the code's out. That was my post before my last one look thru and you will see it. Keep me posted.
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Thursday, March 17th, 2011 AT 2:09 AM
Tiny
TOBYJAY
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Will do - and thanks again for your help and for sticking with this for so long. Mike
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Thursday, March 17th, 2011 AT 2:51 AM
Tiny
SATURNTECH9
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Your welcome your stuck with me thru the good the bad and the ugly lol.
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Thursday, March 17th, 2011 AT 4:43 AM
Tiny
TOBYJAY
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Your instructions have a notation that says to have the engine running when jumping the two terminals to read codes. Below it says to only have the switch on when doing the same thing. I'm going to try it with only the switch on. If that doesn't work, do you think there's any harm in trying the terminal jump with the engine running?
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Thursday, March 17th, 2011 AT 2:35 PM
Tiny
SATURNTECH9
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I always do it with the key in the run position engine off.
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Thursday, March 17th, 2011 AT 4:21 PM
Tiny
TOBYJAY
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Saturntech9 - Here's the latest. First I tried removing the plus battery cable. This caused the check engine light to go off, but it returned after a few minutes use of the car. Then, I located the data link connector. Unfortunately, it's different from the picture you sent. This one is a 16 pin connector with only five wires going to it. If I hold the connector with the longer side up - the fourth and fifth pins from the right are black/white and solid black respectively. On the bottom, The first and third pins from the right are orange and green respectively and the first pin on the left is yellow. Is it possible for me to still manually retrieve codes with what I've got? Thanks. Mike
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Friday, March 18th, 2011 AT 8:33 PM
Tiny
TOBYJAY
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New development - Auto Zone would not read a car before 1996.
Advance Auto put two different readers on that fit the 16 pin plug but neither one could read anything built before 1996. We even tried telling the reader that the car was a 1996 model but it still wouldn't read through my plug. Seems that some sort of computer standardization kicked in on 1996 to the present time. I'm trying leaving the battery cable off all night tonite to see if that makes any difference with the check engine light. Mike
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Friday, March 18th, 2011 AT 10:02 PM
Tiny
SATURNTECH9
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Yeah in 1996 they went to obd2 and a 16 pin connector all the make's had to to make all the emission code's speak the same language and have the same code's emission's wise code's. NOTE: If the Data Link Connector is the 16 PIN type, a scan tool must be used to display diagnostic trouble codes. See procedures for use with a diagnostic scan tool. See: With Manufacturer's Scan Tool that is what I have listed for the 16 pin connector. You would have to get a scan tool that can read the obd1 gm car's to see what code's you have.
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Saturday, March 19th, 2011 AT 4:11 PM
Tiny
TOBYJAY
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Saturntech9 - I've used the car only for very short hops since my last posting. Two days ago I took it on a 1200 mile trip on an interstate. It continued to run normally as far as we could determine, however the mileage was grossly off - down by as much as 25%. Check engine light remains on as well. Sounds like I've got to bite the bullet and take it to a garage that can read a 16 PIN type from 1994.
What's your take on this? Thanks.
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Sunday, April 10th, 2011 AT 1:15 PM
Tiny
SATURNTECH9
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Yeah lets get the codes read and let me know what code numbers you have.
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Monday, April 11th, 2011 AT 1:06 AM
Tiny
TOBYJAY
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Finally found someone with a code reader for 1994 models. Two codes came up. One, # 118 indicates engine coolant temperature circuit, high input. The other, #134, indicates oxygen sensor circuit- no activity. The technician cleared all codes to eliminate any that were old. When the ignition was turned back on, only the #118 came up. It actually indicated a temperature of approx. 300 degrees Farenheit. I'm told that there are separate temperature sensors for the temperature guage itself and for the computer reading -my temperature guage never moves from the normal range (about 190)during daily use and the car has never shown any indications of overheating. One theory that came up was that the temp sender for the computer is sending this very high incorrect reading which causes the computer to adjust engine functions in an attempt to deal with the high number. What do you think about all this?
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Monday, April 11th, 2011 AT 8:22 PM
Tiny
SATURNTECH9
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I would agree you have a bad coolant temp sensor or the wire going from the computer to the sensor or the connector itself. There are two sensors one for the gauge and one the computer.I posted a trouble tree for the code's which includes how you can test the sensor with a multimeter. Also see below the code description I posted.I also posted a wire diagram and which sensor is which and where there located. Let me know what you find.

Code P0118, Engine Coolant Temperature (ECT) Sensor (High Temp Indicated)

Intake Air Temperature (IAT), Engine Coolant Temperature (ECT), Throttle Position (TP), And Trans Temperature Sensors Wiring Schematic

CIRCUIT DESCRIPTION
The Engine Coolant Temperature (ECT) sensor uses a thermistor to vary the signal voltage from the PCM. The PCM applies a voltage on CKT 410 to the sensor. When the engine is cold the sensor (thermistor) resistance is high; therefore, the PCM will see high signal voltage. As the engine warms, the sensor resistance becomes less and the voltage drops. At normal engine operating temperature (85°C to 95°C), the ECT signal will measure about 1.5 to 2.0 volts.

DTC P0118 WILL SET WHEN:

Engine run time is greater than 15 seconds.
Signal voltage indicates engine coolant temperature above 140°C (284°F) for.4 second.
ACTION TAKEN (PCM will default to):
With a current DTC P0118 set, the PCM will turn the high speed cooling fans "ON" and use a default engine coolant temperature value based on run time. The default value will rise to a maximum value of 90°C (194°F). The PCM will illuminate the MIL (Service Engine Soon).

TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.

Determines if conditions necessary to set DTC P0118 exist.
This test will determine if CKT 410 is shorted to ground which will cause the conditions for DTC PO118.
DIAGNOSTIC AIDS
Tech 1 displays engine coolant temperature in degrees. After engine is started, the temperature should rise steadily to about 90°C (194°F) then stabilize when thermostat opens.

An intermittent may be caused by rubbed through wire insulation.

Check for:

CKT 410 for a short to ground.
Intermittent test - With Tech 1, monitor engine coolant temperature while moving related connectors and wiring harness. If the failure is induced, the "engine coolant temperature" display will change. This may help to isolate the location of the malfunction.
Shifted sensor - The "Temperature To Resistance Value" scale may be used to test the engine coolant temperature sensor at various temperature levels to evaluate the possibility of a "shifted" (mis-scaled) sensor, which may result in driveability complaints.
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Monday, April 11th, 2011 AT 8:51 PM
Tiny
TOBYJAY
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Thanks for all the info. The details and amount of information is truly impressive! Your diagram shows two different temperature sensors. Am I correct that the uppermost one near the pulley wheel is the one for the computer?
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Monday, April 11th, 2011 AT 10:51 PM
Tiny
SATURNTECH9
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Your welcome that's the throttle body and yes its the one by the throttle body that you want. Let me know what you find.
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Monday, April 11th, 2011 AT 10:55 PM
Tiny
TOBYJAY
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I believe I've found the sensor that's for the guage cluster but not the sensor for the computer. Any chance you have another view of the location of this sensor? There are various assemblies, cables, etc. In the area shown in your diagram and they may be in the way of what I'm looking for.
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Tuesday, April 12th, 2011 AT 8:29 PM
Tiny
SATURNTECH9
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Does the sensor you found have a yellow wire and a black wire going to it?The sensor you want is by the throttle body.
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Tuesday, April 12th, 2011 AT 8:39 PM
Tiny
TOBYJAY
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The sensor I found is to the right of the throttle body and has a single green wire going to it. I do see a cable with a yellow and a black pair going under the throttle body but I can't feel or see where it ends at a sensor because throttle body etc. Is in the way. Will I need to disassemble the brackets, etc. Of the throttle body to get at this?
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Tuesday, April 12th, 2011 AT 9:10 PM
Tiny
SATURNTECH9
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The one with the single green wire sounds like the sensor for the temp gauge. Try unplugging it when the temp gauge is reading then see if the temp gauge drops. In the diagram it shows the sensor you want in plain view iam trying to find more info on it. The older cars there is less info available to me. Also my computer is giving me trouble so please bear with me.
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Tuesday, April 12th, 2011 AT 9:58 PM
Tiny
TOBYJAY
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I finally found the computer coolant sensor located directly under the throttle body. I can't reach far enough to remove the plug on top. I also discovered that if I turn on the ignition without starting the engine, even with the car totally cold, the two supplemental electric fans behind the radiator come on and run indefinitely even though the vehicle is cold. Seems to me this is further proof of a bad sensor telling the ECM that the temperature is high even when the coolant is cold. I'm told that the only way to reach this sensor is to partially remove or loosen the throttle body. Rather than risk damage to the housing or the gasket, I'm thinking it would be best to let my local mechanic do this. Do you agree with my take on the electric fans and the sensor?
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Friday, April 15th, 2011 AT 3:30 AM

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