If you've got a mechanical fuel pump with a screen, take it apart and see what's inside. Gasoline doesn't dissolve sugar very well; it will recrystzallize at the first opportunity.

Also, replace the fuel filter. Cut open the old one with a hacksaw to inspect it.

Turned out I had been driving around with sugar in my fuel pump for years. Didn't seem to do much damage, other than to cut back on fuel flow. Found some in the float bowl, too.

Mike

Father in law suspects someone put sugar in his gas tank. Engine quit running and that's all I know. How would one test the gas or what do I look for to confirm this has happened.