I have a 1993 F-150 with the 5.0 in it. The truck just had new plugs, and fuel filter put in. I have a issue where it will randomly shut off when coming to a stop and once when easing off from a stop sign. I removed and cleaned the throttle body, turned up the idle some and it still does it. When it shuts off it does have black smoke on start up at times and acts like it can't get any fuel then clears up in a few seconds and runs fine. Going down the road it runs good with no misses and plenty of power. Switching tanks doesn't seem to make any difference so I don't see it being a fuel pump issue. Any help or ideas would be appreciated.

 

There is no manual idle speed adjust. That's a throttle stop screw that prevents the throttle plates from closing too far then sticking in the bore.

Check for codes. I also suggest to inspect the Idle Air Control (IAC ) on the side of the throttlebody. Clean if necessary.

 

Step 1 is to put the throttle stop screw back to where you put it. That is not an idle adjust screw, and you'll mess up the computer's idle control by changing that.

Step 2 is to pull the codes and go from there.

 

So 2 votes for putting the Throttle Stop Screw back and pulling codes.