Nissan Repair: too much fuel, vacuum leaks, premium fuel

Question
1991 nissan pick up 2.4 rough idle sputtering at take off and 50-60 mph cruising i have replaced plugs wires cap button fuel pump filtirs timing chain set at spec 10 degrees premium fuel and i have used many additive and treatments with no weight i can deal with it but when i haul my mowing trailor its real bad i am working on it as we speak i just took off thebreathor and made a lap down the road it was much better

Answer
Hi Sam -

Have you checked for vacuum leaks? Since your car has many vacuum hoses, a good way to check is to get some carburetor cleaner and spray a little mist over different areas of the engine. If you spray over a certain area and the idle improves, you have found the area of concern, and know where to start.

Hope this helps -\
aloha
calvin