Cougar

The contacts on the sensors get corrodid and cause problems like that. There could also be a bad connnection somewhere. Chances are the sensor contacts are bad. Sometimes using a cleaning product like Techron gets things working again.

There have been others here that have cleared some strange problems after cleaning the ground connections.

You may have made a better electrical connection when you cleaned things up. Have you tried spraying some starter fluid into the intake again to see if that helps? You may be correct about the valve timing and things are ok there. Lets say that is good. If that is so there is a really bad problem with cylinder #4 and it also looks like there is a small leak between 2 and 4. The numbers went up in #2 also when you put oil in #4 so it looks like a leak to me. All the inital numbers are low and looks like a pretty worn out engine. You should be seeing numbers around 185 lbs. I can't explain the high numbers you got in #4 unless the exhaust valve isn't opening.

It is interesting to read the postings again about this. I suspect some problems could have been solved by just cleaning the ground connections it the engine area which should help eliminate some of the noise problems that were found.

The trouble may be with the ECU. They can have a transistor fail inside that can cause that trouble. You might see about getting one of those also. Check the model number of yours and write it down so you will have it with you.

The MAF can go bad and I think you have proved it.

The info I have for a '88 model shows the ignition relay is in a brown socket and the fuel pump relay is in a blue one. The previous year may be different though. I'm pretty certain the brown cube is the ignition relay and the silver one is for the fuel pump. Does the pump turn on without having to jumper the connection in the socket? The relay usually will click when they turn on but there may be something else going on that isn't allowing the relay to turn on. Checking for voltage across the coil of the relay will tell you if it should be on or not. The relay should at least turn on for a couple seconds when the ignition is first turned on and after the engine is running it should always be on.

If you don't have at least a test light probe to check for power I suggest you get one. Make sure power is at least getting to the brake switch. If that checks out then see if power is getting passed it. There could be a problem in the wiring beyond the switch that is causing the trouble. I'm not sure what to say about the diagnostic fee charge. If your car has a warranty all the charges should be covered, including any labor charges. If the warranty is limited then maybe that is the issue.

I can understand that alright. It's just when you have two cylinders on the same side that have low compression, the possibility of the valve timing being off has to be considered.

You can't use the turbo on your other engine because they have different compression ratios. If it were me doing this I would go with the GL-10 and fix the engine. Things would be torn apart anyways so it isn't much more work to go through the engine and rebuild it. At least if the body is in good shape.

If the middle brake light turns on while the other ones don't then the trouble isn't with the switch for the brake lights. Check the emergency flasher switch instead. Try cycling it a few times to see if that helps. Also check for a loose connection. I wouldn't change anything out until the trouble is pinned down to the real cause of the problem. Guessing at the cause of the trouble will cost you extra money that would be better spent on a test light probe and a service manual. There should be codes stored that will show why the transmission light is blinking.

It would be a good idea to check the ECU codes to see if the ECU may be shutting down the pump. Since the ignition is working the ECU shouldn't be turning the pump off. The fuel pump relay may be next to the ignition relay under the dash in a blue socket.

The low compression numbers on cylinders 2 and 4 make me think the timing is off by maybe a couple of teeth on that side anyways. I could be wrong.

The starter fluid gets sucked in with the air so the injectors can be out of service and the engine should kick over. You don't want to have the test connectors connected under normal situations as you found out. The ignitor seems your best bet still as was already mentioned. The error code for the air sensor is in regard to the circuit for the sensor. You need to check the wiring between the ECU and the sensor for a problem. There could be a open connection problem, a short to ground on one of the leads, or some other connection problem. The sensor itself could be bad.

You are right, I too wouldn't think those numbers are bad enough to kill the engine. The bad compression numbers on cylinders 2 and 4 may mean there is a problem with the valve timing for that side of the engine. Though there may be a problem with the rings of number 4. Joyboymechanic's comment about the ignitor transistor is a good point. You stated earlier the spark was weak. Replacing the ignitor is a good thing to try at least.

To read the codes I think you tie the black connectors together and look at the LED through the viewing hole in the ECU. You count the long and short pulses to come up with the code numbers. Five short pulses is normal.

The water in the battery can boil if the charging voltage goes beyond 15 volts or one of the cells short out. Which will make a battery about a 10 volt battery instead of 12 volt. The regulator will then kick up the charging rate since it thinks the battery has a low charge on it and that causes real trouble. The old alternator may have had some high AC ripple voltage due to faulty diodes and that caused the water to boil out of the battery. It sounds like you have things under control now. If you have a voltmeter in the dash make sure the voltage doesn't exceed 15 volts and doesn't go below 12 volts for an extended time. The battery will be happy with that.

Don't worry about having a warmed up engine for the compression test. You don't need to do that for what you are checking. The numbers may not be as good with a cold engine but they still should be within perhaps 10 percent of a warm engine. Since the starter fluid trick failed and you have spark getting to plugs the only possiblities of trouble left is low compression or the ignition timing is way off. Just another thought, have you checked for any error codes in the ECU?

Have the battery tested to check the condition of it. The battery may have a shorted cell and that would explain the troubles you are having with the battery and the alternators. I recommend you do not use that battery until it has been checked out, especially if you install another alternator.

A bad cable to the starter is about the only thing left that hasn't been changed out. They can get corrosion inside, on the wires, at the battery.

Those numbers for the coil seem resonable to me. Since you are getting spark I would check the compression next if starting fluid doesn't cause any reaction.

Have you checked to see if this is a fuel delivery problem yet? If not I suggest you spray some starter fluid into the intake and see if the engine fires up then. If you don't get any response from that then check to see if there is spark getting to the plugs. If that is ok then check the compression of the cylinders.

If there is a possibility that the sensor connections got reversed somehow I suggest you swap them and see if that helps.

If you are saying you measured the voltage between the positive side of the battery and sensor wire then that is not what you want to do. You want to measure between the sensor wire and ground. It sounds like the wire may be grounded out.