hi, first time on here. i have a 1993 z28 with an LT1 6spd. just bought the car a week ago and have been coming up on a lot of problems i think were caused by last owner. i bought a GM code reader and im getting code 23 and 25. car starts good, has good idle just under 1 grand and stays steady. if im gentle on the gas ride is rather smooth, but if i floor it the car will sputter around 2500 and then smooth out at about 3 grand. changed plugs, didnt get to wires. new in line fuel filter. car doesnt have MAF sensor installed. also previous owner removed IAT sensor, wires still there but sensor gone. whole is open where sensor goes. im kinda lost, and not to sure if any of this helps. i would appreciate any help. thank you!

....sorry so long. also a buddy of mine called a friend whos GM certified. he said i should replace my TP sensor.

 

The codes are both for the missing IAT sensor. Replace the sensor, and verify that the wires are not damaged.

1993 is the only year F-Body LT1 that does not use a mass air flow (MAF) sensor to measure air flow into the engine. Your ECM reads the inlet air temp (IAT) and the manifold absolute pressure (MAP) and calculates the mass air flow based on RPM, displacement and volumetric efficiency. If the PCM does not have a correct inlet air temp, it can't calculate the mass air flow correctly, which means it can't know how much fuel to add to maintain the required A/F ratio. It will use a default calculation, that will not provide optimum power or response to throttle changes - exactly what you are experiencing.

In addition to screwing up the ECM's A/F calculation, the hole for the missing IAT sensor is allowing unfiltered air to enter the engine.

 

ok sounds good. im gunna replace the iat and check wires. hope this fixes it, thanks!

 

my baby is alive!! ok IAT is in and no more sputtering around 2 grand. even took her for a little spin around the block. thanks a lot!!

 

No wonder. The IAT is crucial for your 1993 speed density engine to run properly.