I have to keep the RPM's above approx 2000 to keep the car running. when i let off it dies. I can take it out on the road and it drives fine until i reach idle rpm's then dies. No check engine light either. here's a list off what's been changed recently;

timing chain, gears and tensioner
cam sensor and interuptor
crank sensor
entire ignition system
IAC sensor
alternator
battery
EGR
O2 sensor

car has ran like a rocket up until this morning, many trips from mississippi to NY.

Check for a carboned up egr, remove and clean it up, look for vacuum leaks, these are first steps.

I agree with the first response to your problem, but check out this. Alot of cars of this age will develop a stuck tcc switch. Transmission converter clutch switch. It is mounted inside the transmission but you have access to the electricl connector.(on outside of transmission,obvious in front or side) If the car runs fine otherwise(doesn't miss upon acceleration etc.) but wants to stall and lose rpms upon every stop such as red lights and stopsigns then try to find this connector and disconnect it to see it the stalling stops. On auto transmission vehicles this acts like the clutch on manual transmissions. It prevents the car from stalling when stopping just like the clutch application would on a manual. You can then decide if this is the problem and live without overdrive or fix it. With a car this old I would just be satisfied to stop the stalling. I disconnected on on a customer of mines '91 Skylark. Expensive to fix professionally. Good Luck!

Don't forget to check the TPS voltage, both input and output through the range to WOT.

Replaced TPS, and IAC.... no change. Pulled EGR off and cleaned it... no change. Tried unplugging what i think was the TCC, no change... note i never got a TCC code on the computer but I did get a "control quadrant module" code. Still no CES codes other than the affected system sensors i messed with. Car fires up perfectly but dies upon idle down. I don't think it's bad gas (see original post). And exhaust system is new. Really stumped on this one!!!!

Could a bad intake manifold cause this?

Thanks

Have you taken a fuel pressure test?

I haven't checked anything fuel related. Think maybe fuel filter or pump? Also what is a good way to check and clean injectors? I've heard there is some way to energize them open once removed and clean them.

Make sure it's not the mass air flow sensor by tapping it with a screwdriver. If it stumbles and idles erractically then thats your problem.

MAF seems ok. I disconnected the the MAF and IAC and the car ran slightly better. Still idled very rough but i was able to drive it. It didn't backfire but had reduced power out on the road. The weird thing is i had a code for the MAF and IAC being disconnected, but when i reconnected the MAF not only did the car run slightly better (idled really fast) but the CES light went out and cleared all codes. Just as i was about to pullinto my drive i got a CES light and the car started idling just like when the MAF was disconnected. Also got a code 23 (IAT sensor), 34 (MAF sensor) and 44 (O2 Sensor; lean exaust). I know for a fact it wasn't running lean, stunk like hell.

Should i just throw in the towel or let this thing nickel and dime me to death?!!!

88 LeSabre Limited
86k orig miles

Decided enough was enough. Sold her for $100 this morning, She still needed a new steering pump, master cylinder rebuild, AC system repair, AC compressor and windshield. I got my money out of her by far!!

Farewell Brown Betty..........

boy u really screwed yourself over on that deal.

good riddins!