1991 Lincoln Town Car Signature V8 4.6L. Sounds like the starter is slipping. The car cranks and eventually starts after much clicking and then a sound like you get when you try to start a car that is already running. The starter solenoid on it is brand new, and just to make sure I just got done swapping out the *new* one with another new one (spare) to be sure it wasn't the starter solenoid. Not sure what is going on or what to do next. Any suggestions? Thanks!

No it sounds more like the starter solenoid sticking, give it a few solid tickles with a hammer to free it up.

Do you have spark and fuel pressure ?

You have no relay to your starter motor. If the starter motor isn't cranking, then first check the battery voltage. It should be around 12.5 volts.
When you crank with the lights on, then do they dim considerably? That's usually a sign of a week battery.
If when you crank, you hear no click of the starter motor solenoid, then that could be your issue.
If you hear a click, but no cranking, then that's likely the starter motor itself which could be faulty, but do check the condition of the battery leads and connection to the starter motor assembly.

hi this sounds like to me you might have a loose baffel in the box, the reason why the sound dissapates when you get to a certain speed is because the baffel is pushed up or down due to the pressure when you slow down the pressure then releases the baffel and it starts rattling again, you might also have a broken clamp on your exhaust or even a missing rubber bush check these out first...good luck

I currently have the same issue with mine. It usually starts after the car has been running a few minutes or if I accelerate quickly. A friend of mine suggested the motor mounts.

HI it sounds like you have a bad starter or relay. First you need to check the battery cables and make sure they are clean not just at the battery but their mounting points also. On the starter you will see a purple wire you need to check the connection there they are prone to failure and cause a no crank condition. If you can put a test light on this same wire while someone tries to crank the engine to see if your getting power to it. If you are then you need to replace the starter. If no power can be found at this wire then your relay is probably bad.

could be the fuel sending unit, which in this case is on the fuel pump in the tank.

check ignition fuse and fuse link.if all is good.looks like ignition switch is bad.

Here are pictures for 1990 Lincoln Town Car Relay/Fuse box under the hood....which may or may not help. It has 40 amps for the heater blower and nothing having to do with A/C in this box

have the starter tested because it sounds like a bad solenoid in the starter and it makes it get hot so it won't start