Missing, loping...changed plugs and wires, distributer cap, checked compression......could it be an injector???

It could be a fuel or compression problem that is causing your misfire. To eliminate a clogged injector as a possible cause, you can swap injectors between cylinders and see if the fault follows the injector in question. Or it could be a fouled or incorrectly gapped spark plug causing the misfire. Do a compression check with the engine warm, preferably right after a misfire event.

Compression good on all 6 cylinders when the engine is hot ?
If yes, it could be an injector.

DETERMIN IF YOUR PROBLEM IS ONE OF THE FOLLOWING BEFORE CHANGING ANYTHING .1.ELECTRICAL
2.FUEL RELATED OR 3. MECHANICAL.

PERORM A COMPRESSION CHECK TO ENSURE THE COMPRESSION IS GOOD .IF THE COMPRESSION IS IN ALL CYLINDERS PROCEED TO CHECK FUEL SYSTEM .REMOVE THE FUEL INJECTORS AND EXAMIN THE INJECTOR TIP FOR CARBON DEPSITS .CHECH FUEL SPRAY PATTERN ,ENSURE INJECTORS ARE ACTUALLY SPRAYING . THEN PROCEED TO EXAMIN THA SPARK PLUGS .LOOK FOR DISCOLOURATION OF SPARK PLUG ELECTRODES OR CARBON DEPOSITS. IN DIAGNOSING PROBLEMS ONE HAS TO SYSTEMATIC OR ELSE YOU WOULD BE WASTING MONEY AND TIME PURCHASING AND REPLACING COMPONENTS WHICH ARE NOT DEFECTIVE . GOOD LUCK .

engine missing could be caused by faulty spark plugs and wires,bad ignition coils,dirty fuel injectors,leaking egr valve,low cylinder compression,intake vacuum leaks.many things will cause engine to miss, first do minor fix,replace distributor cap and rotor,replace spark plugs and wires,clean fuel injectors,replace fuel filter and air filter,if this minor tune up dont help engine and engine still missing, do a vacuum test and compression test to check condition of engine.engine could be worn out have low compression by worn valves and pistons rings.

inspect the wiring for loose connections or bad wiring.

try adjusting first the distributor by turning it. It should adjust the timing. Other than that inspect the timing on the timing chain or the chain may have developed a slack.

CHANGE WIRES PLUGS N DISTRIBUTER.

i would suggest calling the police at this point .

This sounds like a valve problem ( sticky valve) check the compression in each cylinder if it drops from cold test to warm test run a engine cleaner thru it and change the oil and use a additive after that it might come out of it .

probably need new fuel injectors,or plugs wires, replaced the spark plugs, wires, distributer cap and rotor, run it if still the same, do a compression test if the is good replaced fuel injectors

Start with testing the injectors for pulse. Get a NOID light they sell the at almost any auto parts store remove in get plug from injector and plug the noid light into plug look for constant steady (pulse)lighting of noid light. Check all six injector on your strait 6. If all is good remove parke plug wire on at a time from cap and look for increased shaking and less when it replaced(Make sure to use wire puller with rubber insulation to avoid being zapped by spark from coil) Note cylinder with no difference or change when wire is removed. Those would be the problem cylinders. Then get a compression guage and check all cylinders for compression by removing spark plugs and attaching guage to each cylinders, make a not of each cylinder's reading. NOTE THEY SHOULD NOT BE MORE THAN 10 PSI difference in cylinders. Make note of low compression cylinders if any. If compression is good all around spark plugs are good, good ignition wires and you have good pulse pattern from you noid light. The only other problem is BAD INJECTORS and those would be the ones that didn't change when you took off the wires. I have work on these old cressida alot my self. Good Luck contact me if you need more help and if I solve your problem leave me a FIX-YA comment.