• 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
351C Fuel Delivery Problem
Was driving my 1971 mustang yesterday and it started acting like it was running out of gas. I had full tank.  It was sputtering so I pulled of to side of road and looked under hood at my glass see thru fuel filter and saw it was dry. I replaced the fuel filter with a new one and on the way home, it sputtered again. Today, I replaced the mechanical fuel pump. Took it for a test drive and the fuel filter ran dry again. I limped the car home and now I'm kinda stumped. My motor is 351C, .30 over with mild cam and 2v heads. Edelbrock intake and 600 CFM carb. I installed a new fuel tank and sending unit with new hoses before I fired the motor up last year. Any ideas?
Rust in the fuel line, did you see any in the filter?
Bad (dirty) tank of gas clogged the sock on the fuel inlet in the tank.
Rubber hose in the fuel line disintegrating.
Hole in the metal or rubber fuel line letting air in.

“If you can't explain it simply, you don't understand it well enough.”
--Albert Einstein
Don: Yes there was some debris in the fuel filter, it kinda looked like rust. I was thinking maybe the steel fuel line from rear of car to engine compartment may be plugged. I'm gonna check it out this weekend.
Take your fuel line loose at the tank and at the fuel pump. Put white paper towels in a glass jar and put the end that connects to the fuel pump in the jar and towels. Blow compressed air from the rear of the car and see what comes out. Also where the fuel line come through the inner fender under the master cylinder that line can kink and stop fuel.
Did you use ethanol resistant hose and replace all pieces from tank to carburetor with it?
Before installing fuel pump you should check with a vacuum pump like used to bleed brakes. I have had brand new pump have bad diaphragm in last year.
Also check you oil and if it is higher than it should be the fuel pump probably pumped the gas into the engine oil pan if it had a bad diaphragm. Of course that means new oil, filter and check out the fuel pump.

When a man is in the woods and talks and no women are there is he still wrong??
I used fuel hose for the tank connection to the steel lines and everything else up to the carb. I'm gonna try the compressed air to clear the lines. Thanks.
If you didn't use ethanol rated/resistant rubber hose, and you filled up with gas with ethanol in it, the ethanol disintegrates and swells it inside the hose, plugging it up.

“If you can't explain it simply, you don't understand it well enough.”
--Albert Einstein
You said you were going to "clean the lines" ....IF THE OLD TANK WAS VERY GUMMED UP (and in the lines) AIR won't do it.

Get a spool of WEED WRACKER trim line remove, line from the tanks (Plug output tube) and sit and feed the trim line into the fuel line. Push and turn , and removed . See how far you went by comparing to length of tube. Continue from the rear.....then switch to the front. After removing the gas line to the pump -feed the trim line and repeat. Then put a clean oil pan under the back, I would then FLUSH the line (from the front) and NOW USE COMPRESSED AIR to clear the line. TAKE A PHOTO AND POST IT of the stuff in the oil pan!

So I followed your advice and blew compressed air thru the line from the rear up to the front at the fuel pump connection. At first, there was blow back as the air didn't want to go thru the line, then suddenly it pushed thru and I got about 2/3 cup of fuel and a bunch of rusty black sediment and tiny rocks.  I think it's clear now. Hooked the lines back up and taking it for a road test. Thanks again for your help.
Mark, here you go.

[Image: 20181013-175144.jpg]

[Image: 20181013-175137.jpg]
[Image: 20181013-175613.jpg]
Share Thread:  

Possibly Related Threads...
Thread Author Replies Views Last Post
  351c 2v Cam advice ianpala 33 1,174 05-08-2019, 08:05 PM
Last Post: c9zx
  351C EFI don blanchard 13 489 04-28-2019, 11:01 PM
Last Post: detritusmaximus
  351w vs 351c mudbilly 7 438 04-20-2019, 01:15 AM
Last Post: Spike Morelli
  Missing on one cylinder - 351C TheDude 68 1,918 04-18-2019, 02:30 PM
Last Post: TheDude
  Fuel tank venting EvilPuppetMaster 2 137 04-09-2019, 02:24 PM
Last Post: Don C
  Prepping 351C Heads Don C 0 258 04-02-2019, 06:19 PM
Last Post: Don C
  351 Cleveland Oil Restrictors – 351C Oiling Fix Boss1Ray 5 518 03-31-2019, 09:35 AM
Last Post: Carolina_Mountain_Mustangs
  Fuel Pump Parkka 5 172 03-27-2019, 12:22 PM
Last Post: Parkka

Users browsing this thread: 1 Guest(s)