Not Getting Fuel - But Why?
Thread Starter
|
Senior User
Joined: Jul 2006
Posts: 242
Likes: 0
Not Getting Fuel - But Why?
Hey guys,
Working on my '76 2wd with the 300 six. I installed a new poly gas tank last year including filler hose, sending unit, etc. The truck has been running great until recently. At times it won't get fuel up to the carb (I have a clear inline filter to verify this). I thought it might be a problem with the gauge, which read anywhere from 1/2 of a tank to 3/4 of a tank when this problem occurred the last two times, but the last time I filled the tank with just 5 gallons and that brought the gas level up with the filler hose! This DID fix the problem, though, so I'm a bit stumped!
Could the pump be going bad? Is there some weird level that I could have parked the truck on that would not allow it to pump gas even though it was an almost full tank? I'm gonna replace the pump just in case, it's definitely been on there a while, but I'm just hoping that helps - I'm not sure it's the cause of the problem.
Any ideas?
Thanks!
Justin
Working on my '76 2wd with the 300 six. I installed a new poly gas tank last year including filler hose, sending unit, etc. The truck has been running great until recently. At times it won't get fuel up to the carb (I have a clear inline filter to verify this). I thought it might be a problem with the gauge, which read anywhere from 1/2 of a tank to 3/4 of a tank when this problem occurred the last two times, but the last time I filled the tank with just 5 gallons and that brought the gas level up with the filler hose! This DID fix the problem, though, so I'm a bit stumped!
Could the pump be going bad? Is there some weird level that I could have parked the truck on that would not allow it to pump gas even though it was an almost full tank? I'm gonna replace the pump just in case, it's definitely been on there a while, but I'm just hoping that helps - I'm not sure it's the cause of the problem.
Any ideas?
Thanks!
Justin
Thread Starter
|
Senior User
Joined: Jul 2006
Posts: 242
Likes: 0
Yeah, there's only two short rubber lines, and they're in decent shape. It's just odd that adding gas makes a difference, even if it's not low in the first place! My initial thought was that the extra fuel gave it a better gravity feed to the pump, but that seems unlikely. Another thought that I had was that the system had too much internal pressure and that the pump couldn't pull against the pressure. I hear a strong hissing when I remove the cap.
Posting Guru
Joined: Feb 2008
Posts: 2,184
Likes: 0
From: dayton ohio
try a vented gas cap. that should fix the problem.if the tank is not vented then a vacume occurs in the tank and the pump cant pull strong enough against it. the hissing you hear when you remove the cap is air going into the tank.
Thread Starter
|
Senior User
Joined: Jul 2006
Posts: 242
Likes: 0
Any specific one you guys use? I'm running an aftermarket lockable cap now. Oh, and to answer you, Mil1ion, I'm using the poly gas tank from BroncoGraveyard.
Trending Topics
New User
Joined: Jan 2008
Posts: 0
Likes: 24
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
Thread Starter
|
Senior User
Joined: Jul 2006
Posts: 242
Likes: 0
Sorry Mil1ion, I'm a bit fuzzy on those terms "closed or open fuel recovery." I know that the tank I have is the one does NOT have the emissions hole, just the two filler/vent hoses.
I ran the truck yesterday with the cap off, and it ran fine for a while, then as it idled for a few minutes at the end of the day, again no fuel coming past the fuel pump. Plenty of gas in the tank (keep in mind this is a brand new clean tank, too). I disconnected the main fuel line to the pump and could easily suck fuel out of it (although the taste was rather nasty!). Hooked the line back up, and she fired up after a few revolutions and ran fine again.
I ran the truck yesterday with the cap off, and it ran fine for a while, then as it idled for a few minutes at the end of the day, again no fuel coming past the fuel pump. Plenty of gas in the tank (keep in mind this is a brand new clean tank, too). I disconnected the main fuel line to the pump and could easily suck fuel out of it (although the taste was rather nasty!). Hooked the line back up, and she fired up after a few revolutions and ran fine again.
Certified Thread Hijacker
Joined: Aug 2001
Posts: 14,441
Likes: 60
You should have a rubber line from the tank to the fuel line, then another rubber line about half way along the frame rail and then the rubber line connecting the fuel pump to the line.
You mention TWO lines, check the third on the frame rail about half way.
You mention TWO lines, check the third on the frame rail about half way.
Thread Starter
|
Senior User
Joined: Jul 2006
Posts: 242
Likes: 0
I replaced the line from the tank to the main fuel line when I replaced the tank. I figured it was a metal line from that point until it reached the fuel pump's rubber line. I'll check that middle piece out.
Thread Starter
|
Senior User
Joined: Jul 2006
Posts: 242
Likes: 0
The fuel pump works most of the time, that's the confusing part. So I'm sure if I tried hooking it to a gas can it would pull fine - it seems to cut out after the truck has been driven a while and sits or idles after being driven.
Also - when I removed the line from the pump last night, there was fuel right there at the end of the line - which also makes me think it's the pump going bad. Is this symptomatic of mechanical pumps? I've never had one go on me before. I've replaced electric ones, but they usually just GO, and that's it.
Also - when I removed the line from the pump last night, there was fuel right there at the end of the line - which also makes me think it's the pump going bad. Is this symptomatic of mechanical pumps? I've never had one go on me before. I've replaced electric ones, but they usually just GO, and that's it.
Certified Thread Hijacker
Joined: Aug 2001
Posts: 14,441
Likes: 60
Just last fall the pump in my truck went out. I had it idling in the driveway tuning the carburetors, checking timing, went around the block a couple times, had it idling in the driveway maybe an additional 20 minutes, grabbed the dog to go for a cruise down the back roads and made it maybe 3 miles and the engine slowly quit.
That's wierd, I knew it wasn't the module or distributor as those would quickly shut the truck off, but would fire immediately.
So, the truck eventually restarted and I made it 50 feet and wouldn't fire again. We walked back home, got my work truck, and towed it home. The pump was disintegrated inside when I disassembled it.
The pump was roughly 5 years old and had maybe 15,000 miles on it.
Long story short, the pump went suddenly.
That's wierd, I knew it wasn't the module or distributor as those would quickly shut the truck off, but would fire immediately.
So, the truck eventually restarted and I made it 50 feet and wouldn't fire again. We walked back home, got my work truck, and towed it home. The pump was disintegrated inside when I disassembled it.
The pump was roughly 5 years old and had maybe 15,000 miles on it.
Long story short, the pump went suddenly.
Thread Starter
|
Senior User
Joined: Jul 2006
Posts: 242
Likes: 0
Yeah, I'm gonna go with the pump first. I don't know how old it is, but it's the cheapest and easiest part of the problem to troubleshoot first (next being to drop the tank). My theory is that with the new gas tank and gas cap, there's been in increase in internal pressure within the tank, requiring the old pump to work harder. I'll post back to let you guys know how it goes. I've got a 350 mile round trip with the band next Tuesday, so I've gotta get it figured out quick.
Thanks for the help.
Thanks for the help.