Fuel Pressure
Thread Starter
|
Freshman User
Joined: Apr 2013
Posts: 29
Likes: 0
Fuel Pressure
Hi all, my 78 f350 has not been running very good lately. I noticed the coil wire would arc every now and then so I went and got new plugs, wires, cap & rotor. Started it up and ran fine for about a minute. Thinking maybe the fuel filter is dirty so I bought a new one, only clear this time so I could see the fuel coming thru. what I noticed is the filter is not staying full after about 15 seconds after starting. So that leads me to thinking about fuel pressure, what should it be? I am going to pull the tank(thank god it's a dump bed) to make sure I don't have any blockage there. Once that's done the last thing is a weak fuel pump correct?
Thanks for any help.
Reddman
Thanks for any help.
Reddman
Postmaster
Joined: Mar 2011
Posts: 2,698
Likes: 7
From: Taxachusetts
Stock Ford fuel pumps put out ~ 7-8 psi.
Could be the pump's diaphragm is old, brittle and cracked. Take a whiff of the oil on the dipstick. Smell like gas?
Not good if it does. Time to change the fuel pump, oil and filter.
Could be the pump's diaphragm is old, brittle and cracked. Take a whiff of the oil on the dipstick. Smell like gas?
Not good if it does. Time to change the fuel pump, oil and filter.
Thread Starter
|
Freshman User
Joined: Apr 2013
Posts: 29
Likes: 0
Thanks Filthy Beast, I thought it was around 7 PSI but couldn't remember. I'll check it out tonight if I have enough daylight & it isn't raining cats & dogs. Got to love the weather of the northwest.
Reddman
Reddman
Cargo Master
Joined: Nov 2011
Posts: 3,354
Likes: 49
From: Great American SouthWest
could also be any of the "soft" hoses connecting the "hard" lines.
before dropping the tank, you might run a temporary hose from the fuel pump inlet to a gas can, just to see that it does "suck" well, and keeps your new filter in its' happy place.
before dropping the tank, you might run a temporary hose from the fuel pump inlet to a gas can, just to see that it does "suck" well, and keeps your new filter in its' happy place.
Senior User
Joined: Dec 2014
Posts: 279
Likes: 0
From: spokane
As far as weather though... I'll take rain over the snow were getting (not a ton yet but its coming soon) any day of the week.
Trending Topics
Laughing Gas
Joined: Nov 2013
Posts: 1,207
Likes: 60
From: S.E. Louisiana;so far USA
I don't have the '78 shop manual, but the '77 "says" 5-7 PSI for the 300 & 460; and 6-8 for the 302-351W-351M-400; engine temperature "normalized" at idle speed. The minimum volume should be 1 pint in 20 seconds.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
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
Thread Starter
|
Freshman User
Joined: Apr 2013
Posts: 29
Likes: 0
Thanks all,
The weather is suppose to clear this afternoon, Hopefully I'll have time to check this thing out. Their calling for snow over the weekend I'd sure like to get this done before then. I just built a spreader tail gate for this truck & would like to get that done to.
Reddman
The weather is suppose to clear this afternoon, Hopefully I'll have time to check this thing out. Their calling for snow over the weekend I'd sure like to get this done before then. I just built a spreader tail gate for this truck & would like to get that done to.
Reddman
Thread
Thread Starter
Forum
Replies
Last Post
McDonous
1987 - 1996 F150 & Larger F-Series Trucks
15
Oct 22, 2011 08:43 PM
ravens fan
1987 - 1996 F150 & Larger F-Series Trucks
5
Jun 23, 2011 01:03 PM