fuel filter question

[ALANSD]

I replaced the two fuel filters, carb and frame rail; on my 280 this past weekend. My question is on the carb filter. When it goes into the little "can", there was a rubber/spring thing insdie the can i guess to keep the filter under some tension? It seems this would crush down some when you put in the filter. Is that correct or should i have puilled out the rubber thing. Looks like a tapered cone with a spring in it.

After I reinstalled the filters and changed oil and did routine ,aintenace, I took a drive, and now have a pretty good miss about 2200 RPM. It idles ok, but has a tough time getting past that rpm range...will pull my plugs to cvheck them next, but its a coincidence this just seems to have started.
I thought I felt a very slight miss on our last trip a few wekks ago, but not as bad as this is.
Thanks

[PeterH-350LE]

Alan,
Process of elimination always works best.
Take the carb filter out and see what happens.
Ignition module (inside the distributor) failure can have symptoms like fuel starvation.
And, as you know, many of us have installed secondary electr fuel pumps to overcome fuel starvation.
Why now, you may ask, after it worked for a long time. To quote this old mechanic dude, i ask about the misalignment of my front end: It happens because of going down the road...

[ALANSD]

YEAH, I sure do understand. So what of the rubber deal inside the fuel filter housing, am I correct to install the filter over it? It mashes it down some.

[TomW]

On my Quadrajet, the fuel filter filters by trapping contaminates on the inside of the pleated material. A rubber check valve, which is part of the filter itself, keeps the contaminates inside the filter when the engine is not running.

The filter is spring loaded against the incoming fuel so that if the filter was to become plugged, fuel line pressure would overcome the spring force, and allow unfiltered fuel to bypass the clogged filter & keep you off the side of the road.

If I were to install the filter backwards, the system would see it as a clogged filter. If my fuel pump was weak, I could see a distinct possibility of not enough gas being able to bypass to sufficiently run the engine at higher rpms.

Tom

[ALANSD]

So how do i know if it was backwards. One side had metal grommet on the bottom the other had a rubber seal. The rubber cone in the spot where the filter slides in stays there also then?

This seems elementary but I have not worked on a carb in a millenium. Other than to clean it,etc.

[ALANSD]

here is a photo I found that may help anyone else doing this r&r

[TomW]

The shiny metal end of the filter goes against the spring; The "rubber end" is where the check valve is, and where the fuel enters from the fitting you unscrewed to gain access to the filter.

Tom

[ALANSD]

Originally Posted by tcwilliams

The shiny metal end of the filter goes against the spring; The "rubber end" is where the check valve is, and where the fuel enters from the fitting you unscrewed to gain access to the filter.

Tom

well I guess that probably is what I did wrong, i'm pretty sure i put the rubber end against the rubber spring. I will change that as soon as I get home. Thanks

while on the subject of fuel filters, If you install an inline spin carttridge type, do you have to cut the metal fuel lines, or can you put it in replacement for the rail mounted can type? I like the looks of the Perma-cool I saw on Jeg's.