Ok, so here'* the story. I found this car through Craigslist and bought it even though it had been neglected. The PO hadn't changed the oil for 2 years. The car was overheating due to a bad cooling fan relay and gunky coolant. It was running rough, stalling, overheating and backfiring through the exhaust when I bough it.

Since I've had the car, little over a week, I've done an engine flush, added new oil, drove the car 100 miles, changed the oil again, new coolant, new platinum plugs and new wires, replaced the cooling fan relay, ripped off the muffler which was in pieces and rattling around...

So, I've got the car to where it no longer overheats and runs pretty decent now. Every little thing I do gives it a pretty noticeable improvement. I added some Seafoam to the gas tank to clean the fuel system.

The car is a daily driver now, and drives and shifts great. Only problem I'm having are the intermittent rough running and hesitation. The car is in pretty decent shape, body is good and it shifts very nicely for it'* age. 121k on the odometer.

I was wondering if there is anything I can do to improve things? I don't want to end up stranded somewhere. I bought the car for 300.00 full well knowing what it needed, and I'm willing to do the work. I've fallen madly in love and want to get this relationship right for the long haul!

Thanks!

Sounds like it is coming along better..lets add some things to look at and to do.
If I was unsure of condition of tank and fuel, I would add a fuel water remover, and fuel staybilzer, and a mid to high grade fuel for a few tanks. Air filter box clean it inside & replace air filter. Using throttle body spray cleaner, take the intake hose off, and spray at 2000 rpm a half a can into throttle body or completely remove it and so a service on TB. Clean the IAC (intake air control) unit. Find someone with a good shop scanner and check for all codes, engine , body, transmission etc.. Consider serving trans with a new filter and Dexron VI (6) I also add a bottle of LubeGard red for trans.
Inspect drive belt, pulleys and check battery by a load test. Then test the alternator with input voltage while lights on defroster & heat fan on high and then no load with all off.
Suction out the power steering fluid and put new in. I use LubeGard PS fluid quiet it down & runs cooler/slicker. Brake fluid can be considered eventually too DOT4 please.
Just a few ideas..

oh and I forgot add this to oil....
http://www.homehardware.ca/products/300/86153861.jpg
and drive it ..then your engine will be cleaner & real quiet!!!! Works excellent!
Buy 2 cans for you next two oil changes ok to add right now would be a good idea.

It would also be a good idea to pull the MAF sensor and clean it with MAF Cleaner spray.

Any Service Engine Soon lights?

You might also want to change the fuel filter. It could be causing the hesitation.

No CEL'* on..

I haven't thought too much about the fuel filter. Where is it at on a '91 Lesabre?

The odd thing is,
it'll hesitate and stutter with light acceleration starting off..
but when I give it some gas, (WOT)
It'll get right up there and hold its speed steadily and without hesitation.

It'* got me a bit baffled, wouldn't a clogged fuel filter restrict WOT?

Managed to break a fuel line trying to remove the old filter. So, I can't drive it at the moment. Stuck a rubber plug in it for now, just going to have to get new fuel lines when I can. Where can I find 'em?

They don't make fuel lines "per" application. Its all custom work done using off the shelf fuel line parts and tools to make your own flares etc.

oh bummer,on breaking line. It is one of those parts that rusts and gets changed so infrequently, you got to use PB Blaster and let it soak a while before attempting to remove it. When I got the Pk Ave, I let a shop replace the fuel filter, knowing he had lines in stock just in case it broke. Luckily he soaked mine and it came off ok.
Hope you can find some lines, or a shop that can help.

Just about any shop has the basic necessities to repair/replace fuel lines. Just stay away from the ones that suggest using a length of rubber hose to fill in the gaps.