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JosephACavin · May 30, 2007, 11:36 AM

1987 Merc Cougar Fuel Pump Problem

3.8, CFI, Auto, approx 145,000.

Here is how it all atarted and what I have done.

One Sunday as we were leaving to go to church the battery was dead in my wifes car. we took my truck instead. After church I charged it for a few hours. It cranked and ran fine. I told the wife to drive my truck the next day and I would check it out. The next day the battery is dead so I charge and ddrive it to Advance Auto get them to check the Battery and it was in need of a real charge but was fine. I had them to check the the alternator and there was the trouble it was not putting out enough. I had them jump me off and drove the car home. I took the battery back to advance and had them charge it over night. The next day I took the alternator off and being that it was still under warrenty exchanged for another. I reinstalled and turned the key and it starts just fine but to my dismay cuts off within 2 seconds.

Here is the problem now. I keep checking all the normal things out but nothing works, it cranks then cuts off 2 seconds later. I spray starting fluid and it will keep running. I pour gas in it and it keeps running as long as fuel is added.

I am sitting there turning the key and notice I do not hear the fuel pump load up in the on position. I turn a little further and there it is. I turn the key and then just baarely release it and she purrs as long as I hold it there.

As soon as I let go, I can hear the relay click over at the glove box and it cuts off. So I say it has to be the ignition switch,

RIGHT?

Wrong I put a brand new one in and it will not start.

I am about ready to run a new wire to the fuel pump and put a lighted toggle switch on the dash.

Have any thoiughts.

TxGreaseMonkey · May 30, 2007, 01:02 PM

. Check/replace the main fuel pump relay:

Zip Code Entry at PartsAmerica.com

. Check the fuel pump inertia switch, which turns off the fuel pump in case of a collision. See if the inertia switch has "popped." If so, push the reset button.

JosephACavin · May 30, 2007, 01:07 PM

I have checked that by using a jumper wire and it has the same effect. It has to be before the relay where the problem is I believe. I am unfortunately thinking ECM.

TxGreaseMonkey · May 30, 2007, 01:14 PM

Yes, if the ECM is bad the main relay won't work properly. Check for proper reference voltages on the MAP-Barro Sensor or Throttle Position Sensor, when the ignition is turned to ON. If the voltages are way low, then the ECM is probably bad.

JosephACavin · May 30, 2007, 01:25 PM

What would a low voltage be?

TxGreaseMonkey · May 30, 2007, 01:26 PM

Be sure to test all under-dash and under-hood fuses with a test light or multimeter.

TxGreaseMonkey · May 30, 2007, 01:28 PM

The proper reference voltage is likely 5 volts. If it's bad, it will probably be a fraction of a volt.

JosephACavin · May 30, 2007, 01:29 PM

Thanks

JosephACavin · Jun 15, 2007, 07:10 AM

I have found and fixed the problem. It was a wire that comes from the battery ground and goes where ever it does but it has a connector and the connector was bad after making that connection it runs just fine. Thought I would pass this along.