A friend of mines 1994 3000gt non turbo is having an issue with engine sputter at wot, Specifically, the engine fails to climb above around 4k rpm when the accelerator is fully depressed. This happens whether under load or just revving in neutral, The sputter sounds like an engine whose carburetor is out of adjustment and there is noticeable power loss while on the road. Interestingly, the engine has no trouble reaching redline (and runs fine) when the throttle is gradually increased,
Thinking it might be the tps, I tried to adjust it via the service manual instructions but wasn't able to fit my feeler gauge against the set screw and throttle lever. Instead, I moved the tps in small increments, each time checking to see if the sputter went away. No change. I then swapped in a known working tps and did the same routine, Again, no change .
Might anyone have a suggestion on what could be going on? The cel isn't on, so I don't know if checking the codes would yield any info,