1990 Mercury Marquis • V8 2WD Automatic • 90,000 miles

1990 Mercury Grand Marquis mileage: 90,000. One day when I passed a car and the engine started to miss. I tested the spark and the #2 cyl had no spark. I then tested for spark at the cap to eliminate the plug and wire and had no spark coming out of the #2 tower, but if I raise the throttle, it will get a very weak spark. Just to let you know I have replaced cap, rotor, coil, module and pick-up. The real problem is if I shut the engine off and restart the miss goes away and I can make it miss again by flooring it under a load. When the miss is there it's always #2 no spark and with the spark tester on #2 I can get it to spark by unplugging the timing spout connector and when I plug it back in it will lose spark again. If I leave the spout connector out it won't miss or with spout in and restart engine as long as I don't floor it under a load. I bought a wire diagram book from Ford factory and the circuit# is 324 which is a yellow with light green stripe. It goes from TIF module to the spout and from the spout to pin 36 at the EEC module. Pin #36 on the EEC description says transmission overdrive switch to heat module. I don't know what the heat module is and 324 circuit seems to end at the EEC. I was wondering if it is part of the EEC and if the EEC is what is bad?
November 19, 2010.

In view of the testing you have done, would be to try replacing the EEC with a known good unit

Nov 19, 2010.