My 1990 RX-7 GTU has been having problems recently. The car accelerates the same at 1/3 throttle as it does at full throttle, it also doevnt have the high end punch that it used to. The car has studdering proplems at idle, and it runs really hot. Im suspecting that it is either too lean (maybe from clogged injectors or fuel filter), or maybe the timing is too advanced. Any help would be great. Thanks.