CIS fuel filter. how often do you change it
 

the title says it all.
i have at least 30k miles on my filter.
i checked my tank not long ago and it was very clean.
what symptoms would you expect from a dirty filter? high RPM bad performance? bad starting? or just bad all around performance
i have another one ready to go on, just curious, actually a slow day at work and looking for something to talk about.

I change mine bi annually and I drive my car about 10,000kms a year.
I know that's way to often but my 911 is one of the few luxuries I allow in my life.
I've never had any issues with my fuel system so I can't comment on the symptoms of a dirty filter.

What does the service manual say?

As an example according to the Bentley, my VW Golf VR6 filter should be changed every 50,000kms.
(This car also gets a new filter bi annually)

Hope that helps.

i have a 75, and i like to change it at least once a year, but i only drive it around 5-6 k a year. If your 77 is like my 75 the pump is in the rear, and there is enough room to put a filter in front of the pump. Gives me peace of mind. Napa has a short clear plastic one with 2 10 mm fittings, works great, very easy to change.

pump is up front. i guess i am long over due

CIS needs clean fuel and a filter is a cheap insurance! I change mine once a year and I might drive up to 5K if I am lucky!

Bob
73.5T

Depends somewhat on size.

SC's have big and small depending on what year.

I like the bigger one and configured the lines and fittings for it.

Mark it with date and Mileage for referrence. :)

unless its a stock 74
 

Try and find those original OEM fuel filters for a 73 1/2 and 74 CIS . . . $$$$$$ if you can find them.

Fortunately my car came with 3 extra filters per original owner records, over 22K miles and still flowing fine.