My friend just recently acquired an '85 GSL-SE. It's in pretty good shape and all stock. At cruising speed, at steady throttle, the car will sputter and hesitate. During acceleration it's fine, and idles fine during deceleration or normal idle.

The plugs, wires, and dizzy have been replaced, as well as the fuel filter. The fuel pump is stock, should that be the next troubleshooting step? I drove the car and it drives fine except at steady throttle when you're just trying to maintain speed.

All the work I've done on the 12A and carbs... I can't figure these FIs out!

Thanks in advance for the help.

 

Check the TPS and clean the BAC.

 

i had the same problem and it was the small filter that goes in the fuel line right before the pump looks like a small cone filter it was full of crap. Also drive the **** out of it thats what i did since it sat for 8 years without moving.

 

if it only does it at part throttle, and the fuel filterS have been replaced/cleaned then i would be tempted to look at the o2 sensor.

idle and heavy throttle its in open loop and not looking at the o2. cruise it is.

you should also check and adjust as needed the TPS and idle speed/mixture, its in the FSM, very simple. i like to do it once in the winter and once in the summer. especially if the car is new to you

 

TPS.

Reset it and be done.