Hey guys I have a '85 SE and recently came into issues with it running with reduced power. It doesn't seem to pull as hard as it use to and I've noticed my mileage is even worse. <10mpg on a bone stock car. The biggest symptoms noticed so far are: reduced power, idle hunt (probably alternator related), when driving up a slope at anything but full throttle I feel the engine surge in power, and finally it does not like to rev out to 7k as it use too without issue. I know my alternator isn't charging at 100%, is it a possibility that it is just not putting out a strong enough spark?
A couple of days ago I replaced the coolant temp sensor and that did not clear up the symptoms. I also smoked the intake system and found no leaks surprisingly. I went through the vacuum hose on the booster. I tried adjusting the idle with the service screw on the intake but it would not change no matter where the screw was. About 2 months ago I noticed the cat was clogged and hollowed it out and reinstalled into the car. At this point I'm trying to figure out if it is fuel, spark, or compression related. Any tips to lead me in the right direction would be awesome!

 

Any difficulty starting the car? Poor compression (usually due to worn Oil Control Rings) leads to difficulty starting the engine once it's hot; it'll start cold just fine, but once it's hot you'll never get it started without pull-starting the car with another vehicle. Also, how many miles are on that engine?

Based on your fuel mileage quote, you might want to look at your Fuel Injectors which one or both may be stuck open, but then you'd be dealing with flooding problems. Does the exhaust smell of excessive fuel? Any backfiring? A long shot would be that the car is in fact running on one rotor (search on that here + my username) and could be caused by a bad pigtail connector to the Fuel Injector off of the harness where it lays at the back of the Water Pump. When this happens, you'll be way down on power (half-power, go figure...), and fuel mileage will suffer greatly. Test by running the engine at idle, and then moving the wiring harness back and forth to test for intermittent connection. If the engine magically pops back to life, you found the problem.

Spark is something worth looking at - and without more information - you may throw a good tune-up at it and see if it responds. That should include new Spark Plugs, new Plug Wires, and a Cap and Rotor. These can all be purchased for about $50-60 and will improve overall performance over parts that are 10 years old and have never been changed. In fact, you should pull all 4 Spark Plugs and give them a close look to see what color they are and whether they're wet. This, combined with information above could point us in the right direction.

There are 3 catalytic converters on an -SE, two little ones right after the manifold box and one big one just behind that which also gets injected air from the Air Pump, along with providing return exhaust back pressure to operate the '6'-ports. If one of your cats was clogged, it's possible the others are clogged, too. If you're running stock exhaust, best to look at all of them, as they're designed to work in sequence, two 'Monolithic' converters, and the Catalytic Converter (the big one). This is a high probability problem that would prevent the car from revving easily to redline.

I doubt your Alternator has anything to do with the symptoms at hand. If your battery even registers voltage, it will run your ignition system. I know this after having an tiny Optima die last month that was completely discharged, but still able to run the ignition system enough to get me home after jumping it. The alternator probably provided enough tang to the battery to keep the engine running. Point being, you don't need a lot of cold cranking amps to spin a rotary engine with any kind of mileage on it. Post back with some answers and we'll go from there,