Cougar

I haven't worked on the sunroof so I can't say this for sure but I would guess the problem may be due to a misadjusted cutout switch position.

I am thinking fuel pump related also, though the other suggestions are a good possibility. The fuel pump relay is my vote.

I would suspect the problem is either with the drivers door lock switch or the switch that is mounted on the outside door lock mechanism. You will have to get inside the door panel to work either of them. You could try disconnecting them one at a time to see which one is the culprit.

The problem you are having seems like it may be with the main battery ground lead. It may have internal corrosion and have high resistance. If you haven't cleaned the battery terminals and cable connections then do that first to see it that will help. I would check the cables using a voltmeter to look for voltage drop across the wire while trying to start the car. You can also use a jumper cable to bypass the the main battery leads to find the problem. The problem may also be with the battery so measuring the voltage across it while cranking may turn up a internal problem.

It sounds like there is a whole lot of roo work going on around there. Glad you got it running and hopefully that will be it for problems for some time now.

Instead of guessing what is wrong I would start checking for voltage getting to the ignition system. The fuse may be be good but you need to verify where voltage is getting to. A simple test light probe should work fine to locate the trouble spot.

That isn't too bad of a price but you may be able to get one for half of that if you do some more looking. Check the Marketplace section of this site and place a request for one. I wouldn't worry about damaging the new ECU, I doubt there is a problem with anything external to it. It just failed internally, it happens.

The transistor I replaced was in the fuel pump circuit. Your problem may have different components involved. You should use a digital voltmeter to do the checking with if you do this. You need to trace the wiring from the ground side of the injector to the inside of the ECU and see what the contact is tied to. It may be going to a power transistor lead. Transistors are basically back to back diodes and need to be checked for forward and reverse conductivity. Using a digital meter to in the diode check mode, the display will usually show between .5 to .7 volts in the forward bias direction. The reverse direction will usually show 'OL' or over limit. You should be able to do a search on the web to find out how to check transistors. Here is one link for your info. http://www.elexp.com/t_test.htm

Checking my manual, it shows that fuse going to MB-3 which feeds the ECU, fuel pump relay, OBD-2 service connector, and the main relay. The main relay feeds voltage to the oxygen sensors, pressure sources switching solenoid valve, and purge control solenoid valve. I would suspect the problem is near the oxygen sensors first.

It sounds to me that the transistor switching in the ECU to provide the ground for the injector has failed. I would try another ECU to see what happens. I have repaired a couple of ECU's that had the same problem with the fuel pump ground circuit. It turned out to be a small TO-92 style driver transistor had failed in both of the units. I found these by doing a diode test with my DVM meter.

I would get a wiring diagram for the car. The factory manuals are the best. Using it you will know what wires need to checked for power. It will save you time and usually money also.

I would check the brakes. Particularly the front ones. One side may be grabbing better than than the other side. It would be good to check the front end also for a problem.

Check the adjustment of the disable switch(s) on the brake, and clutch pedals if you have a MT.

I wouldn't recommend using a air gauge to look at fuel pressures with. That may be dangerous to have gasoline in side the gauge that is not designed to measure fluid pressures.

The ohm readings you gave sound alright to me.

I don't know if you have room for one, but using an air impact wrench set at low torque works will on removing stuborn bolts. Also there is a product called Areo Kroil that works really well as a penetrant. http://www.kanolabs.com/

If you don't have anything to test for voltage with then you need to purchase a test light probe at least or a voltmeter. You need to see where voltage is getting to when this problem happens and not guess at it. I have some wiring info for a '97 model and will check that when I get home in about a week. I don't know if the fuse is powering something else but it seems that it may be considering the current rating. Since you replaced all the suspect items it would seem something else is causing the problem. It is strange that it either doesn't work at all or blows the fuse intermittently.

You don't state what fuse you are replacing. It would help to know what the number of the fuse is so we could see what is being fed by that fuse. Part of the problem seems to an intermittent connection since things worked ok after you cleaned the wiring connections.

You stated the you heard the whistleing after you turned the car off. If that is so, then what you may be hearing is the power supply for the dash display. The vacuum florescent display requires a higher voltage then the 12 volts of the car system power. The sound you hear may be from a switching power supply for the higher supply voltage. I'm not sure what to say about the ripple out of the alternator. It sounds a little high but it may be ok. I would check the output with a oscilloscope before replacing the alternator to see if one of the phase ripples is missing. Make sure your charging system connections are clean also.

The pulses are pretty slow while trying to start the car. One pulse for each ignition. You can see them with the probe easily when they are there.

Good thought Josh. Pulling the connector off will do about the same thing as swapping the injectors.

Your welcome Serac. Thanks for the feedback.

I also received one of those cases with my '88 when I purchased it new.

Now that is believeable.

They are usually under the dash above the drivers feet.