You won't know, just replace it every so often. I recommend every 75,000 miles.
If I were you I would just replace the fuel filter if it is cloged.
engine does not start
if the fuel FILTER is cloged then the car either wont start if it is real bad or before that it will be real slugish especially going up hills.
bad gas / need a tune up /fuel filter cloged/ pcv valve / an air hose could be cloged any one of these things could cause this problem. i work for an auto part store i get this question a lot.
If you ran the tank dry, you may have a cloged filter in the tank or if it got through in the line filter.
Pool filters do not get cloged the pump is the problem
If it is carburated, Gumout the carb, check all fuel filters, spark plug wires, and distrubutor. thanks it was a cloged fuel filter it had me puzzled as it ran great in park or neutral
The iac valve may be bad. located on throttle body,drivers side.
fuel pump bad or cloged filter...if it just did it all of a sudden i would say fuel pump
Is it an electronic or mechanical
Change the fuel filter first. If that doesn't help, change the fuel pump.
fuel filter is recommended to be changed every 15,000 miles