Cougar

My info shows it is on the intake manifold.

If the coolant sensor for the ECU is defective it can cause the fuel to be rich since the ECU doesn't get the correct temperature reading of the coolant. This is a different sensor than the temperature gauge sensor and a fairly common failure.

I'm not sure since I have never had to replace one but a number of folks here have had to. Now that you kind of know what to look for it may help you spot them.

My info for a '88 shows there are four relays near the middle of the dash. The first one in line is the blower relay. The relays a usually round and about 1 inch in diameter. They plug into sockets. You should use a test light to check for power getting to the blower and the CD player.

You most likely have a bad blower relay. I think it is located under the dash, near the end, on the driver's side. If not there then the middle of the dash. You may be able to locate it by tapping on the relays with the power on to the blower and see if it will make it run.

Perhaps the wires were defective from the start. I think your model has a cold start valve. The starting problem may be from that.

Mary, As the others said, red is the positive lead of the charger and goes to the positive post of the battery. I would guess the flashing lights are trying to tell you the condition of the battery as it charges. You may find that the lights go from flashing to steady on as the battery charges up. First the yellow then the green. The instructions were trying to tell you to connect the charger by first disconnecting the battery ground lead to the vehicle and then connect the charger leads to the battery. Then plug the charger into a AC outlet to power the charger. This is to prevent sparks that could possibly ignite hydrogen gas fumes from the battery. You don't want to see what a exploding battery is like. When the battery is charged remove the AC power to the charger and then disconnect the battery charger leads to help prevent sparking. Sparks near a lead acid battery is a bad thing. Especially after a battery has been charged at a high rate and lots of bubbling occurs in the battery, creating the explosive gas. Since you are using a trickle charger this shouldn't be too much of a problem but it is good to be safe. Turning your head away from the battery just before you disconnect the charger is a good thing to do just in case, along with wearing some safety glasses. Glen

Bad fuel gauge readings are fairly common. Some models use 2 sensors in the fuel tank and when one sensor is bad it can cause the type of problem you are having. Usually just removing the sensor and cleaning the wiper contacts corrects the trouble. I heard of one case where someone used the fuel additive Techron in the tank and it cleaned the contacts so the gauge worked correctly. You might try it to see if it will work for you.

Wayne, I don't think he has damaged the new sensor but I do think you are correct about the problem being inside the ECU. If it is, hopefully the problem is just due to a loose wire that ties to the sensor lead and he can repair it. From the test results that Imdue got on his replaced sensor it sounds like it is ok also.

Well you have a very good meter there. It sounds like the circuit to the sensor may have a high impedence on it or there is something wrong with the ECU for that circuit. Have you checked the wiring between the ECU and the O2 sensor for a connection problem by looking at the resistance of the wires between the sensor and the ECU, as Shawn rightly suggested? A bad wire connection to the sensor should generate a error code if the ECU is working correctly. Does disconnecting the O2 sensor cause the MIL to light? If not, then the ECU O2 sensor circuit is not working correctly or the there is something wrong with the warning light circuit. If the voltage stays at 3.8 volts with the sensor disconnected then the ECU is the problem in my opinion. You may be able to fix it by checking the pins internally that tie to the sensor. Perhaps a lead is not making good connection to the board. I have heard of other people fixing the ECU this way. To Starsea: By heating the O2 sensor with a torch the sensor is looking at the gases of the flame and putting out a voltage that corresponds to the gas flame conditions. Since the flame is burning clean the voltage is about in the middle of the sensor output. If the fuel mixture was rich the output voltage would be around 1 volt.

Check for 12 volt power getting to the ECU. I think fuse #5 and #12 are the ones you need. Check the voltage on the fuses and make sure it is ok. You will notice little slots on the top of the fuses you can check for power at. Power needs to be checked with a meter. You can't just look at the fuses and say things are ok.

Actually, 1 and 3 are on the passenger side.

Usually the sensor voltage runs between .1 to 1 volt so that is way too high of a voltage. Where are you placing the meter probes to get this reading and what kind of a meter are you using? Is it a digital meter with a 10 megohm input impedence?

The plug might not be the problem but it may be bad internally. If it is bad the spark will seek the least resistance to ground which may be through the plug boot. You don't want to go through another plug wire if the plug is bad so that is why I suggest a new plug be put in. The problem may also have been caused by not seating the wire on the plug properly.

I would suggest replacing the plug also that goes to that bad wire. The plug may be bad and if so, that is what caused the wire to go bad.

I suppose the ignition switch could be shorted but it seems that it would be hard to make that happen, yet it seems that is the case. It may also be a sticky ignition relay causing this to happen. I would think the switches would be interchangeable but I haven't done it so I can't say this for sure.

I would check the wires that supposed to be connected when the trouble codes are to be looked at. I don't think you really want them connected during normal driving.

I would try using a small flat bladed screwdriver and see if you can pry along the side of the button to pop it back out. Once it is out you may try and see if you can use a light oil on the latching area to see if that helps free the movement up.

Try connecting the 47 and 68 ohm resistors in parallel and then hook them up to see if that works. It should. EDIT By tieing the two resistors in parallel this will make the total resistance now about 28 ohms which may be more what the ECU wants to see as a normal circuit load and not trip a code thinking there is a circuit problem.

Have you checked for spark and done the commpression test yet? If so, what were the results?

Since they didn't change things then it sounds like the resistance may need to be less than 40 ohms for the ECU to be happy. It would be interesting to test the limits if one had the time to do that.

Glad you got it fixed. Thanks for the update.

I would guess the resistance will have to be within a certain limit, say 30 to 100 ohms, but I don't know for sure. I think if the resistance is outside the limits then the ECU will think there is either a short or a open on the line depending on which side the resistor is not meeting spec. You may need about a 5 watt resistor to be on the safe side for power dissipation.

I would try spraying some starter fluid into the intake to see if that helps get some fire going in the engine.

I thought the TPS voltage range was .5 to 5 volts with .5 volts being wide open throttle or WOT. That is what I seems to recall at least. The bucking may also be due to a clogged fuel filter or weak fuel pump. Welcome to the forum.