Fuel Injection Roblem PART 2

["Chris C" <petleech@xxxx>]

We continue to have problems with our '83 DMC. We have gone through 
the entire injection system, cleaning the fuel tank, replacing the 
fuel pump, filter, accumulator, and injector rubber seals. We have 
also replaced the oxygen sensor. Originally the distributor plunger 
was jammed but we freed this using injector cleaner and compressed 
air. All the injectors are spraying with a normal spray pattern. We 
have checked the fuel pressure, control pressure, and rest pressure, 
and all are normal. The car will not idle happily and hunts. The 
contol pressure regulator is clean and the frequency valve buzzes 
during warm up. The compression is consistent in all 6 cylinders 
within 10 psi. We have tried adjusting the mixture but it will only 
run rich and the gas consumption is very poor {about 18mpg on 
highway}. We have changed the plugs and set the timing to 13 degrees 
BTDC as specified. The engine revs up fine and smoothly when the car 
is stationary. Under load, it accelerates in spurts and then 
hesitates. When decelerating it jerks and hunts. We cannot detect any 
vacuum leaks.Can you give us any suggestions?
Thanks, 
John 16727