Re: EEC-IV power relay, 1985 Grand Marquis
The engine just cuts off a lot (dies and restarts?). At 55, it just feels really rough. Normally, I don't have to pull over, but when it's at its worst it will lose about 15 mph before it restarts. It also dies at stoplights, sometimes but not very often. A couple of weeks ago I noticed that the behavior was much like what happens if I turn the ignition key off and then back on, except that I can't switch it on and off as fast as the car can. Also, when I turn the ignition off and on, the cruise control turns off, but when the engine dies and restarts on its own, the cruise control continues to work. We've replaced the TFI ignition module, coil, oxygen sensor, the EEC-IV power relay and a whole lot of brittle vacuum lines. I'm tempted to take out the wiring harness and spread it out and look for bad wires. I'm also tempted to try replacing the EEC-IV.
Also, the diagnostics report problems with the EGR. I read somewhere that the EEC-IV automatically disables the EGR if it isn't working, so I haven't gotten very serious about looking into that yet.
Also, replacing the coil really helped out a lot. Before we did that, the car wouldn't restart from time to time. All the other changes haven't really made any difference.