| After getting the Z back on the road after about six months of sitting, I drained the tank and dumped in some fresh 92. Driving it that night everything seemed normal and my spiffy new fuel pressure gauge read right on the money (36-37 at idle and appropriate ramp up as vacuum went down). Drove into town to spend a chunk of change on some 101 octane and as I was pulling out the power died suddenly. I let off the throttle and it seemed to come back a bit though still underpowered but now the fuel pressure was down around 28 psi. Limping home I've found the following: Threw a code 43, throttle position sensor circuit. Cleaned some contacts and volt/ohm checked the sensor. Volts are good (.45 closed and 3.875 WOT) but the ohms are a bit off (in spec closed at 1k ohms but WOT is only 8k instead of 9k). Fuel pressure stays up around normal when cold then drops down as the car is driven. It hovers down around 27-28 psi at idle eventually. Fuel pump ohms fine and seems to be in working condition as it provides ample and correct fuel pressure during the first ten minutes or so (up to 57 psi that I've seen). The fuel pressure gauge is accurate, I double checked it with a known good manual gauge. After clearing the code 43 the first time I encountered it again during a test drive in another high load/low rpm situation (going up a hill in 4th gear at around 2300 rpm). This only happens after the fuel pressure starts to drop. Nothing is burnt inside the fuel pump control box. Fuel pressure regulator has about 20k on it though I don't think that would be the issue given that the fuel pressure sensor is between it and the fuel filter. Fuel filter has not been changed since it's been sitting and also has around 20k on it. Sourcing a new one tomorrow. Any thoughts or suggestions are appreciated.
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