My 1989 Cadillac Brougham 307 starts up and pulls off but doesn't go more than 15 miles or so...replaced ignition coil and alternator, wire, spark plugs.Could it be my fuel pump is bad..?

You have replaced a lot of parts. The only one you didn't mention was the Ignition Control Module. Why did you start the repairs in the first place? What were the symptoms? The symptoms that you forwarded for this vehicle can be caused by: Faulty coil, pickup coil or distributor, ignition control module, timing, cap, rotor, spark plug wires, related ignition wiring harness, blown fuse or aftermarket security system. Usually when you replace a part with a new one, it should fix that issue. Not often but sometimes the new part is defective. Do you own a repair manual for this vehicle? Do you own a multimeter and a test light? These engines are pretty easy to work on. It is really important to stop and start from the beginning. Unless you have already reverified everything 3X. You should verify the timing and distributor orientation first. Timing is set when cyl. #1 is on TDC on the compression stroke. This can be accidentally confused with the exhaust stroke. Please write back, let me know what you are looking for and I will do my best to help. Good Luck.

1. The ignition system on your 5.0L uses a distributor type system and will include the following components:
   1. Ignition control module (ICM). Depending on the year of your specific Ford, it'll have a inner-fender mounted ignition control module or a distributor mounted ignition control module. hot sure which you have.
   2. Ignition coil. you replaced it.
   3. PIP (Profile Ignition Pickup) sensor. This is Ford's name for the crank sensor and is mounted inside the distributor. The most common name for this component is the pick up coil.
   4. Distributor cap and rotor. you replaced
   5. Spark plug wires. you replaced.
2. The thing to keep in mind about the ignition system is that all engine cylinders must get spark and the one thing that will stop the ignition system from creating spark on a wholesale scale is a BAD crank sensor.Have you pulled a plug then using some insulated pliers grounded it to the vehicle and turned it over to see if you have spark, that'll tell you alot.takes two people of course.Best of luck and hope this helps.

Usually, if you only have 1 cylinder misfiring, you have either a bad spark plug or bad spark plug wire. If you replace the cylinder 6 spark plug and still have a misfire condition, replace your spark plug wires. If replacing the plug and wires doesn't fix the problem, replace the ignition coil.

I’m happy to help further over the phone at https://www.6ya.com/expert/jeremy_69f3cc28d95bf514

It would be worth checking or changing the air, fuel and oil filters and if that doesn't help try getting the engine codes checked with an obd reader.
Hope this helps.

You can test coil by pulling coil wire and holding close to a grounded source while someone cranks the car (wear gloves strongly advised). The only way to test an alternator if car is not running, is to take alternator off & bring to a parts store to have them bench test it.

It's not a direct bolt in. (sorry) Olds mounts and housing aren't even close. Just about any olds motor (you can find them at any salvage/engine rebuilder pretty reasonable) will bolt in. It would take alot of work to work the chev into Caddy.

check the alternator fuse that can be a fuse link by the battery pole,check alternator voltage on the alternator red wire or connector,it should the same as on the battery ,check ground wires for loose intermitent contact

outta gas? water or impurities in the fuel causing fouling?? check spark plugs do a visual

When it won't start check for spark , pull a spark plug wire an hold it near ground (metal on the engine ) have s helper crank the engine . Is there spark ? If no check power an ground at the ignition control module , check control . In side the ignition module are transistors ,these energize the coil (control spark ) It can be tested with a test light . Check out scanner danner videos on youtube . But if there is spark , spray some starting fluid into the engine throttle plate an see if it starts then . If it does you have a fuel problem .

From karjunkie:

If the plugs get wet, then you have a spark problem somewhere in the ignition system. Pull a spark plug and hold it against a ground while you turn the engine over. You need to see a fat blue spark. If not, check the distributor, spark plug wires and coils. An easy way to test for spark is with an inexpensive spark tester. This is a device that is readily available at most auto supply stores. If the plugs do not fire properly, check the spark plug wires for fraying or cracking. Next, you need to check the coil(s). If firing voltage is low (weak spark), measure the coil primary and secondary resistance with an ohmmeter. If it is out of specifications, replace the coil. Also, make sure the coil is receiving normal voltage from the PCM or ignition module. If it is low, check the charging system for anything that may be reducing alternator output (battery and alternator cable connections, ground connections and voltage output).