I need help with a problem that I have been unable to identify. I have a miss
or flutter in the engine while driving at a steady speed of 50 - 75 mph. It starts to miss or surge and if you accelerate it gets worse. If you downshift
to 3d gear it clears up and you can go all the way to redline without a miss.
This event only happens once in a while and I can't make it occur. Sometimes you have to drive a few hundred miles or more.
Lately I have noticed this happens when the engine temp is over normal.
I have had this in to a couple of dealerships and put on a scope and other
related test equipment and they find it perfect. Nothing wrong.
They recommend to start changing parts (electrical, fuel inj, etc) one at a
time and road test until the problem goes away.
Anybody have any problems like this?

Car is a stock 94 Z28 with 72,00 miles.

 

try to find someone with a MAF near you and see if you can borrow it for a while. it sounds like your car is going into speed density mode because the maf fails out. does the car ever not want to start or start and then sound like it's not getting fuel?

when was the last time you did a tune up?...wires, plugs, 02 sensors?

 

Thanks for the info. I will check the MAF. No one to borrow from.

Car starts great every time. Have replaced plugs, wires,etc but not the 02
sensor.