Cougar

Keep in mind when checking switches that you don't have to physically get to get to them in order to check them out. All you need to know is what wires tie to them and then use your meter to check the voltage across them. When the switch is closed it will have no voltage across it if it is ok.

My info shows there is a AC relay box with 4 relays and 2 fuses in it. Do you have something like that under the hood? The switch in the evaporator may be the problem. To see if that is the problem you should be able to measure across the leads going to it and see if the switch is closed or not. The AC control circuitry is pretty complicated and it may be easier to purchase a manual that covers the wiring for your car in order to try and solve this problem.

I suspect the problem you are having at high speed is due to a fuel delivery problem. If changing the filter doesn't help with this then I would check the fuel pressure to see if a weak pump is causing the trouble.

I'm not sure what to think on this Andrew. It kind of sounds to me that there may be a vacuum leak somewhere, possibly the transmission area. If you have any vacuum lines going to the transmission area try pinching them off to see if that makes any difference in the idle.

Check the voltage across the thermoswitch and see if you have 12 volts across it. If not, then the problem is a lack of power to the circuit. My manual for a '88 shows fuse 15 is for the fan and the power goes to the fan then through the thermoswitch and to ground. Since you bypassed the switch already and know the fan works the problem seems to be due to a lack of power in the circuit so check the fuses. I wouldn't bother removing the switch until you prove it is really bad. I would guess that the switch should go to zero ohms at around 205 deg. F.

You may be thinking that the plus and minus side of the coil refers to the battery and it doesn't, at least not exactly. I don't think the minus side of the coil is really tied directly to case ground of the coil. There are windings between it and ground. Check out references on autotransformers to see how they work. You need to find out why the O2 sensor circuit is having a problem. That is the most critical code you have. Since the plugs and wires have been changed fairly recently it would seem they are fine but can't be totally ruled out still. Another possible problem may be a intake manifold leak. Have you checked for that? As far as the solenoids go the codes are set by electrical problems with the circuit to them. The air lines through them can be bad but it won't set a code.

Along with GD, I doubt that the coil is bad. Though I do think you may be correct about the plugwires being a problem. It the plugs and wires haven't been changed in a long time I would consider doing that over the coil swap. Also go over the engine ground leads. Some members have found trouble there.

I assume that the car was running ok at one time with the current sensor. I don't think you can use the other type TPS without changing out the ECU also. Going by the 2.8 volt reading you took it seems that the wiper is either not making the full travel of the resistor or, the sensor is bad.

I recommend you change out the sparkplug and plugwire for #4 to see if that will correct the problem.

Good deal. Thanks for the feedback.

It really doesn't matter which style of TPS you have. The main thing is that it works smoothly through the range of resistance. Instead of measuring the resistance I would look at the voltage through the whole range. You should be able to catch rough spots looking at the fast response bar on the meter display of the Fluke.

I will have access to my data on Wednesday to look at the system. There is a control module that may be causing the trouble.

Welcome to the forum here. Hope you like it. The five flashes are normal and will always be there. I think it indicates what kind of transmission is installed. You didn't state if the sparkplugs were changed. If not, you might check those out.

You stated that you think the spark is jumping around. Check the wires at night while trying to start the engine. If the spark is jumping to ground outside the wires you may have a coil body grounding problem. Make sure the coil mounting is clean. The fact that the tach is having trouble indicates there is a problem around the coil area. You can also place a test light probe on the minus side of the coil and watch the firing pulses to make sure that is ok while you crank the engine.

If there is a seperate connector for injectors 3 and 4 make sure the connection is in good shape. Also check the wiring between the ECU and to those injectors. There may also be some external resistors that need to be checked though they be internal to the ECU.

Newer vehicles have a switch on the clutch pedal so you have to press the clutch in order to start it.

If the starter system proves out to be ok then check the ignition switch connector in the steering column. A common problem has been the terminal contacts that carry the high current get burned after time.

I think so. I don't have access to my service data right now to check that.

Does the relay under the dash work when the switch is turned on?

You are correct about that. Check the switch for the brake pedal next. It may need adjusting. A common problem. You shouldn't need to remove the switch to check it out. Just measure the voltage across the switch with the igniton on and you should see a voltage change when the pedal is pressed. I think the relay for the compressor is under the hood. You could try swapping relays to see if you can find a problem that way.

Glad you got it fixed Jerry. Thanks for the update. If the problem occurs again you will know the first place to check at least.

It could be the CTS was going out. It is hard to say. You need to check the sensor and the wiring to it. After you correct that then the other code will most likely go away.

If you haven't replaced the fuel filter I would start with that since this problem sounds like a lack of fuel. If that doesn't help then check the fuel pressure. You may need to replace a weak fuel pump. The problem also may be a lack of spark or you need to replace some old plugs.

The P040 means the engine is running too rich and it is probably due to the bad CTS sensor or the wiring to it which the second code is saying. Before replacing the CTS sensor make sure there is voltage getting to it and the wiring to it is okay. If the ECU doesn't see that the engine has warmed up using the CTS signal it will make the engine run rich.

A note about clearing the codes. A short time ago I needed to renew my IM certificate and due to my battery being discharged the ECU cleared the memory. This included the memory for the monitiors. Since they were not ready for checking I had to perform a number of things with the engine and driving to make enough of the monitiors to set so I could pass the IM test. It took me three attemps of driving to get enough of them to set so I could get the testing done. While I was at the test station the IM tech was kind enough to get the info I needed to do in order to make the ECU run the self tests. It was while doing this that I learned from him that when the using a reader or scanner to clear the codes it also clears the monitors. I didn't know this before. So just beware of clearing codes, especially if you have a IM test coming up shortly. Edit: This info really applies to OBD-2 systems and isn't really a concern for type 1 systems.