You have a large vacuum leak, most likely the idle control valve hoses, but it could be the plastic housing between the fuel distributor and manifold, vacuum line to the brake booster, or the booster itself.

Check the idle control valve hoses -- the idle control valve is under the air filter housing (take the housing off -- three 10 mm nuts, one front, one rear, one on the fender side), then squeeze the hoses from the manifold to the ICV -- sliver can about half the size of a coke can. Most likely rock hard, and now loose on the nipples.

Check all the other vacuum lines as well -- most likely the rubber is all rock hard, or worse, slime. You can replace the rubber parts with 1/8" vac line from McParts, but any T or Y parts should be gotten from a dealer or indy -- the plastic crap at McParts isn't a good substitute.

If that doesn't fix it, remove the vac line to the brake booster and put a finger over the fitting -- if the vac goes up, the check valve seat or the booster is bad.

You should also inspect the ignition system -- timing must be OK, and the capr, rotor, and wires must be good. Any traces of current leakage mean new wires, they don't last forever. A bad set of plugs can also cause running problems.....

So can a tank of dead gas -- has this car been sitting a long time?

Note that a tank full of crap will plug a new filter very quickly, and a bad fuel pump relay can make it act this way as well......

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!