Car will not go past 10mph and when given gas rpm go up as if car is in netural ,and car also jerks like I'm stopping and going and at times can barely push 5mph after stopping,but does not Stahl and

Changed distributor cap and plugs.checked
air filter and pretty clean.had a friend look
and says carb isn't clogged CU's tchecked
tailpipe. I then had a guy I work with look at
it and he also be lives its not carb or
Cadillac converter CU's o2sensor is reading
fine ..he then drove while his reader hooked
up and said that something about numbers
were jumping all over fro the -s to the +s,.so,
due to numbers he checked spider injector
and sensor plugged unto and sensor had
gasoline in/on it that apparently should not
be there,so he believes its the spider
injector, that one may be cracked and that
explains y my car is doing that.before I
spend money I don't have I like to know any
other suggestions of what it could be or it
could very well be spi injector.. Please any
suggestions ...