A large vacuum leak can do that.
.044 inch , according to fordparts.com
1
yes as long as you put it on right
5W-30 That's the factory recommendation for that engine size. And Castrol High Mileage works really great for me in my 1981 Ford F-150 with a 4.9L inline six.
advance your timing
4.9L Inline-6, 5.0 v8, 5.8L V8
You can find a 1981 Ford F150 manual transmission diagram inside the vehicle's owner's manual. Some auto stores also have the diagram available.
Check with your parts store. Most carry at retofit kit.
CHECK THE FUEL PRESSURE, MAY NEED ELECTRIC FUEL PUMP REPLACED.
Yes, Ford made a 402040 bench seat for the 1995 Ford F150 XL model with the in line 6 engine.
Most oxygen sensors are in the exhaust pipe....between the exhaust manifold and the catalytic converter.
you may have too much vaccum in the lines