Fuel Pump Mismatched Issues- Extended Cab Vs. Regular Cab Affecting Range.

[Kirby N.]

I am wondering if anyone has experienced the same issue as I have.

I have a 1991 Extended Cab 4.0 Ranger.

in 2019 I decided to change the fuel pump because I had the bed off. The stock one was working perfectly fine. I used a carter pump for an extended cab truck. Of course I chucked the stock pump so I can't really check it. I immediately noticed that my range had been shortened from about 300 miles per tank to 250. I also noticed that it would run out of gas when the guage said 1/4 tank was left.

So I figured out that the regular cab pumps were like 1/2" deeper than the extended cab pumps. So I purchased a new Delphi regular cab pump. It fit, although a little tight. It also didn't read on my gauge correctly, but I was able to bend the arm until it read correctly.

Well, it went about 4 years and died. I would notice cutting out on hills, and especially when it was hot out and I was low on fuel. So I put in a Carter for a regular cab. It lasted 1 road trip and started acting up.

So I decided a motrocraft would be a good idea. I ordered a Motorcraft PFS-37 on eBay. $400. New Old Stock. It was for an extended cab. I got it home and it was 1/2" shorter than the replacement. So I ordered a PFS-38- a regular cab pump. It was longer, but this time I drained the tank and guess what? It was bottoming out in the tank. Like tight to the bottom of the tank and that is where the pickup is.

SO I decided to put in the PFS-37. Today it ran out of gas. According to the gauge, I still said I had 1/4 to 3/8 of a tank left. Only took 15.7 gallons. It used to take 20 gallons.

Has anyone else had this issue? I really wish I had the original pump! It wasn't even giving me problems when I replaced it!

 

[RonD]

Just put the Motorcraft pump on the Delphi regular cab pump assembly

Not sure why these don't fit, really haven't read about that issue, yes regular cab 17gal tank and extended cab 20gal tank would be different assemblies, but extended cab assembly should fit 20gal tank

For the float, put assembly standing up on a flat surface, bend float arm so when its hanging down all the way its about 1" to 1.5" above the surface, that should be about 2gal left when on Empty

 

[Kirby N.]

I do have a new carter regular cab pump that I warrantied. The issue is that I believe the regular cab pumps are bottoming out on my tank and that is what is causing them to expire early. I also think the float is bottoming on the contours of the tank and that is why it is hanging up at 3/8ths of a tank- so I don’t think your idea of setting the float it will work. But I can certainly take it out when the tank is empty and manipulate the float until it shows empty.

it would be pretty hard to modify the Carter pump to be shorter. There is two hard lines that go down to the bottom. I might try though.

I was just hoping someone would have a remedy for me and have experienced the same garbage- especially after I spent $400 on a motorcraft pump.

I think if I run into a 91 extended cab in The junk yard soon I am going to pull the pump for research purposes!