Fuel Pump Issue

[CopperNick]

"Changed the filter with the check valve facing the fuel line." Being the curious soul that I am, why would the fuel? filter have a check valve?? Almost without exception the fuel filters I have seen and used are marked for direction of flow but this is the first time i have heard of one possessing a check valve. It's late and I am tired and seriously bent from doing body work on one of my vehicles so would someone far more learned and knowledgeable than moi intervene here and suggest why a gas or fuel filter would come equipped with a check valve so I can add to the fund of my personal knowledge base?

Thx.

Nick

 

[69hurstolds]

AC Delco GF471, aka GM p/n 5651803 fuel filter used in a SLEW of post 1976 engines, has a check valve in the end of it. Most of the 307 Olds engines used this filter. The idea behind the check valve was to prevent drainback and sucking out fuel from the filter line back to the tank.

They used this check valve filter in Corvettes too, and some of the 'vette guys were complaining that their engines were leaning out at higher RPMs in 2nd and 3rd gear. Turns out the valve was sticking and causing issues. Swapped filter to a non-check valve unit- problem solved. May work well in a stock engine, but for spirited and high speed driving, it's probably restrictive AF.

The AC Delco GF441, aka GM p/n 5650906 is the filter WITHOUT the check valve which can directly replace the GF471.

See that black rubber looking crap on the end of the filter? You can pull that out and there's the check valve. Little spring loaded thing.

 

[fleming442]

Is it fixed yet?

 

[CopperNick]

First of all a big Thank you to 69HurstOlds for pointing out that the fuel filter being discussed here is the one that is resident in the carb. I must have been looking in the other direction because that little point never made it to my attention. I had sort of thought all along that it was a universal external in line filter that was the subject under review. Which brings up an interesting thought, is this system running double filters, that is the one in the carb and an external one in the feed side of the fuel line as well?

I seem to recall the last time I had a fuel feed issue that getting rid of that goofy little internal filter and using a larger external in line version instead would likely fix it; the conversion did seem to help. In this case, a full on fuel system inspection and rehab is beginning to look more and more desirable.

 

[shadowreap]

Sorry for replying late, been all over the place. The issue has been resolved. It was a two part problem: First the engine wasn't getting a spark, after toying around I realized it was the distributor that had to be changed. The next issue was there being a fuel leak at the fuel hose exiting the tank. With those two changes the car runs well now. But, the fuel gage is questionable so I figured eventually I will get to changing the sending unit down the line. But for now the car starts and runs without any issue.

A big thank you to all who chipped in and offered advice. Thanks for helping out this newbie.

 

[fleming442]

There are some things to check on the wiring before you dive in to replacing the sender.
- Ground at the tank
-Corrosion on the ribbon cable that runs front to back
-Loose connection at the gauge cluster
-Operation of the gauge itself

 

[MontesbyE]

Check for cracked and or broken rubber lines in the system. Sucking air?