305 TBI has a weird hesitation at light throttle along with a lack of
power. For those of you who have driven carb equipped cars this has all
the earmarks of a bad accelerator pump.
Car has 340k miles on it, but runs like a top except for this.
Idles super smooth.
Cap and rotor changed.
Fuel filter changed.
MAP sensor swapped with a known good one.
Throttle body cleaned out.
No obvious vaccuum leaks.
Temp heater door on air cleaner is fine.
O2 sensor replaced last year. Jumpering the EDL connector while driving
shows it going nicely from lean to rich (when I nail the throttle) and it
is obviously in closed loop.
It's really weird, if you step down lightly on the throttle it will
hesitate, and cut out a little bit but not all the time. If you press
further down it will run fine except on the hiway it feels "spongy" and
It's like there are sags in the acceleration or somthing.
I am thinking Cat convertor clogged? It's the original.
Plugs/wires? Not that old.
Knock sensor hosed causing timing to not increase correctly?