I have a 91 5.0 tpi z28, most of the time when i hit the gas pedal then take foot of it right away the rpms go down to under 500 the oil gauge raises up past 60psi the volt meter drops, sometimes the car dies, and sometimes it will idle back up and be fine, also when driving down road the car feels like it bucks (or misses cant tell) i can feel it the most around 40mph and above. Have new plugs, wires, cap, rotor, fuel filter, injectors are all at 17 ohms, my next thing was to check my timing. This problem is stumping me i not sure what else to do to fix problem.
Thanks

 

Well for starters obvious stuff first any check engine codes? Also I'm going to assume this car is stock or does it have any modifications?

 

no engine codes, as far as I know it is stock I bought it a month ago. The guy I bought it from only drove it a couple times after he bought it so he didn't know if the person before him did anytng to it. I checked the timing t was set at 8 degrees and I put it back to 6 seems to run better at 8, I noticed the bucking more around 20mph on 6 degrees and less at 45mph(but still there), more at 45mph then 20mph at 8 degrees

 

may need tune up,or spray carb cleaner aroung intake system sounds like vacum leak,and if its dieing its a pretty big one

 

Fixed the problem not sure, what it was, but when i replaced the TPS and the connector, also put the timing at 0 degrees it doesn't buck anymore and the rpms don't drop down anymore

 

Start simple. Doubtful, but possibly a clogged fuel filter? Your timing should be at 6 degrees BTDC.