First you need to dump the codes. Being a '93, it should be an EEC system-which allows a user to dump the diagnostic codes without a scanner. You need a piece of wire, a paperclip, piece of mig welding wire, anything that will conduct electricity. fordfuelinjection.com has the instructions how to do that. It's geared toward a Mustang but same principles apply...locations may be different though.
Just because the CEL (check engine lamp) is not on doesn't mean that nothing's wrong. The computer stores codes too for I believe 50 drive cycles. Might be 100. Many times dumping the codes will give a clue as to what's going on...I do it about once a month just to keep a watch on things.
2nd...keep in mind that a 3.8 isn't anything to write home about, especially in a heavy thunderbird. I think a 4 cylinder Mustang is faster. Well maybe not but it's a close race.
Mods...there's some things you can do, but the heads just don't flow much air so a head change is usually in order to open them up. 4.2 trucks and 3.9 Mustangs had dual port heads (split port) and intakes...they are the hot ticket for stock Essex performance. Then you're going to get into exhaust, intakes, blowers and turbos with the latter two being enough to blow the block to smitherines...or at least bust the crankshaft and lift the heads.
Surprised your current 3.8 hasn't lost a gasket yet. Impressive! 99% of them leak coolant into the engine with that many miles on them.
Just because the CEL (check engine lamp) is not on doesn't mean that nothing's wrong. The computer stores codes too for I believe 50 drive cycles. Might be 100. Many times dumping the codes will give a clue as to what's going on...I do it about once a month just to keep a watch on things.
2nd...keep in mind that a 3.8 isn't anything to write home about, especially in a heavy thunderbird. I think a 4 cylinder Mustang is faster. Well maybe not but it's a close race.
Mods...there's some things you can do, but the heads just don't flow much air so a head change is usually in order to open them up. 4.2 trucks and 3.9 Mustangs had dual port heads (split port) and intakes...they are the hot ticket for stock Essex performance. Then you're going to get into exhaust, intakes, blowers and turbos with the latter two being enough to blow the block to smitherines...or at least bust the crankshaft and lift the heads.
Surprised your current 3.8 hasn't lost a gasket yet. Impressive! 99% of them leak coolant into the engine with that many miles on them.