Cougar

You might try replacing the PCV valve and then the O2 sensor if PCV replacement doesn't help.

Glad to hear that you got it fixed. I would have to wonder why the pump wasn't turning if it was getting voltage to it. You may want to replace it anyways if you are sure that there isn't any other place that could be a problem with the voltage getting to the pump. If the pump has never been replaced you got a good amount of service out of that one.

I agree with those that suggest the alternator as the problem but before you replace it I recommend you first verify it is the source of the trouble. There may be a loose wire to it or something simple like that. If you do replace the alternator it would also be wise to have the battery load tested to see what condition it is in. It may help save you further trouble later on down the road.

My info only shows a blu/yel wire tied to the relay for power, and a blk wire for ground going to the pump.

My info only shows 2 wires going to the fuel pump for a '91 Legacy. A blu/yel wire provides power from the relay and a black wire ties to ground.

Sounds like a bad connection in the main power buss area to the main panel under the hood. Try cleaning the battery posts also.

I forgot about the carb on my first post but my info shows the ECU for a carb model also. Check the fusible links for a loose connection. That may be where the voltage is dropping at.

The rev sensor is the control box for the pump. You should be able to see the b/w and blu/r wires running to it. Edit: Checking my info again it looks like the b/w power wire also runs to 2 connections on the ECU along with one of the check connectors.

That's a nice looking rig One Eye. Looking at the pictures; there is some stange looking white stuff on the hood and windshield. By the looks of it, the car was also inspected by one of the locals there. I'm sure it passed the approval process with them too.

My info shows that fuse #11 ties to the coil and pump via a blk/wht wire. The b/w wire also ties to the rev sensor and then the feed to the pump is on a blu/red wire. The problem may be within the rev sensor. You could try running fused power to each of the areas, one at a time, using about a 5 amp fuse and see if blows on one particular circuit.

Keep up the good work on learning about the wiring system Mariposa. You will be able to fix things pretty quickly after getting a little familiar with things in the electrical world. The bad ground connection may be in the light switch or in a connector to the lights. One way to eliminate the light switch is to see if the high beams work in the flash position, which is the other switch position for the high beams. If the highs work in the flash position then the switch is at fault since the two positions share the same path to the lights. If the lights still don't work then the trouble is a wire connection between the switch and the lights. The red/wht wire that Gloyale mentioned is the return path (ground) for the high beams. Until there is a current flow in the circuit, there will be 12 volts floating on that wire. When the circuit is closed by the switch and it makes the ground connection, current will flow and the voltage will then be across the light filament, or load, in this case. This may sound a little strange right now to you but don't be too concerned. You will know later on as you tinker in the strange science of electrons and understand Ohm's Law. I commend you on your willingness to try and understand. Getting a book that covers DC theory will help you a lot in leaning about it. Edit: My info shows that the r/w wire ties to a 8 pin connector that is on the far left side under the dash. Where all the other wires come through. If you can find it you may be able to just unplug the connector and replug it back together to fix this problem.

The lights to those areas you mention are on a different circuit. The light bulbs may just be burned out. If the blower isn't working at any speed then the trouble is most likely with the relay. It could also be the blower motor itself is jammed or bad.

You are correct Msteel. I have repaired some ECUs that had some problems in the analog area.

If the motor isn't working on any of the speeds, including high, then the resistors are probably ok. The relay is the most likely suspect and is most likely under the dash possibly near the steering column. They plug into a socket and it may be round.

I assume you have already checked for any bad fuses in the panels under the dash and the hood. If they are ok I would suspect the fuel pump relay is the problem for a non working pump, though the pump could be bad.

I don't know why the fuse didn't blow out unless it is over rated for the circuit it is supposed to protect. I would guess it should be rated for about 15 amps. You can replace the harness or try repairing the damaged areas by splicing in new sections of wire to replace the bad spots. If you do that I recommend you solder the connections and carefully tape the bare spots or use heat shrink tubing to cover them. Use a wire gauge at least as big as the original size wire.

Check for any codes in the ECU, and check for spark along with the compression. These things will show you what direction you need to pursue on for repair work. If those items are ok then try spraying in a little starter fluid into the intake to see if that will fire things up a little.

You will have to replace the fuse holder and fuse in that case.

You state the fuse melted. By that, do you mean the fuse holder melted or just the internal link inside the fuse? If the outside of the fuse is a problem then the trouble is due to a poor connection to the fuse.

Once a link goes bad it doesn't repair itself. They can have a intermittent connection though and cause things to work intermittently. Links carry a good amount of current and supply power to a lot of things tied to them.

I would think it over for a day if it isn't too late already. You may regret the purchase later on if spare money gets short.

Here is a couple more thoughts. Since the engine is always dying at a certain time it would seem unlikely to me that this problem is due to a faulty relay but I won't rule it out totally. It seems to me that the ECU is shutting things down for some reason. Another relay to check out is the main relay. Make sure power is getting to ECU pins 1 and 2 when the trouble occurs. The same power connection goes to the injectors also so maybe this relay is causing the trouble. Since there is a code being set, the problem may be related to it. Even though you disconnected the lead, it may need to see a voltage signal to make things work correctly. The code description is: P1722 Subaru - Automatic Transmission Diagnosis Circuit High Input While I am not sure what this signal does, it may cause the ECU to shut the engine down. Looking at the engine schematic I noticed that there is a connection from the TPS to the transmission area. The wiper of the TPS goes to the system somewhere so maybe this is related to the trouble.

Since the engine is being fuel starved somehow it must be the injector circuit is causing this or the fuel pressure is being cut off somehow. Check the power going to the injectors and make sure it isn't being cut out somehow. Using an analog meter may help to check that. You may need a scope also to see if the pulse width of the signal is decreasing. You may need to check the fuel pressure using a gauge.

Good thought about the fuel lines P73. I think this same thing happened to someone else here recently. I'll bet you nailed it.

Check to make sure the MAF sensor is working correctly.