my 91'z28 (305 tpi) started acting up a couple of weeks ago. when i would give the car gas it would hesitate for a split second (rpms would drop slightly) and then the car was fine. i added a fuel injector cleaner (chevron w/techron) yesterday and filled the tank.

this morning the car acted like it usually has (slight dips in the rpm), but when i left work today the car was acting crazy. the RPMs would drop down alot and cause the car to buck. it seems to only happen under 2000rpm. after 2000rpm the car seems fine. there are no funny noises from the engine and the idle is as steady as the day i bought the car (years ago).

please help me fix this problem

thak you in advance,

riz

 

My TPI always gives me crap when I put injector cleaner through it. It will idle rough, have dips in rpm and everything you were describing. - as for the hesitation, my original 350TPI didn't have that, but my current 305TPI does - no clue

 

my 305 tpi idles bad also not sure why and does not do it all the time
but in the case of the hesitation i would put the accel coil that fits in the stock location
i go one and all hesitation was gone

 

turns out that my fuel injectors were clogged. 1 week after i put the cleaner in the car ran great.