Have an issue with an 88 lincoln town car signiture series. The thing jerks on acceleration and when climbing a hill, power is reduced also. I have replaced the fuel pump , wires, cap and rotor. The car was overheated prior to this problem but I don’t know if it’s related. Someone mentioned an oil switch or something but I don’t know any thing about it. Any suggestions?
What about the spark plugs?
Are you sure it’s the engine and not torque converter shudder?
Is the TV cable correctly adjusted?
Possibly fuel pressure is weak.
You need to find out a few things first.
what is the condition of the engine’s insides. Do a compression test and a leakdown test and post the results here.
If these come out okay, and even if not, you’ll need to assess the condition of the ignition system. Honestly, the only definitive way I know to do this is by using an oscilloscope. If you cannot use one, then at least you can “read” the condition of the spark plugs (that’ll tell you a lot), and accelerate the engine manually via the throttle cable pulley and see if you can detect any misfiring. Doing it at night might show you arcing, and that’s a good diagnostic trick too.
you’ll also need to assess the engine for vacuum leaks and/or valve problems. This can be done using a vacuum gage. The instructions will be in the kit and perahsp in a Haynes manual…which you should have.
if you still have found nothing, check the fuel pressure and the pressure regulator, as Rod suggested.
In summary, you’re checking the compression of the engine,
checking for a headgasket leak,
checking the ignition system for breakdown of a component or its insulation,
checking for vacuum leaks,
checking for oil burning (crud on the plugs),
and checking the condition of the valves.
Somewhere in amongst all this you’ll probably find your problem.
And by doing all these things, especiially vy revving the engine by hand, you’ll be also determining whether it’s the engine or the torqe converter that Tardis suggested.
If the engine is carburated, you have some more work ahead of you so post back.