Zero fuel pressure...
Thread Starter
|
Freshman User
Joined: May 2007
Posts: 37
Likes: 0
Zero fuel pressure...
My 92 f-150 4.9l stopped running the other day. It would start then immediately die, start and die. I checked for pressure at the rail, and it read zero. I could hear the pump kicking on for a second when turning the key, but it would not build pressure at all. So I plugged the lines and switched to my rear tank(I had a faulty check vale in the front tank, it would just pump gas out of the rear to the front) and it ran fine for a day. The next morning it wouldn't start, so I dropped the rear tank to replace the pump. Well that tank was about rusted out, so I decided to cap the rear lines and drop the front tank and just fix that one. So front tank dropped, replaced the pump assembly, put it back up, hooked the lines up and still no pressure, I mean none. I've checked the fuses, filter, the relays, the pump kicks on when the key is turned, but won't build any pressure. I have replaced the pressure regulator, and I checked that for gas and it's dry...what else could cause this? Desperate to get this truck going as I need it for a job I'm doing.
Thread Starter
|
Freshman User
Joined: May 2007
Posts: 37
Likes: 0
Checked the filter again, and it's not clogged. The fuel inside came out really clean even after shaking it up. I can also blow through it both ways with hardly any resistance...any other thoughts? Would trapped air in the return or feed sides of the lines cause this? I capped the lines to the rear tank with brass compression fittings and caps back near the rear axle because that's where I could get at them easily, so there's about 4ft of line after the front tank line split off the main line.
Thread Starter
|
Freshman User
Joined: May 2007
Posts: 37
Likes: 0
It does. There's the feed and return lines coming off the fuel rail heading towards the back of the truck. At the front tank, the lines have a "T" that branches off a feed line and a return line for the front tank and then continue to the rear. I capped just the rear lines off at by the rear axle. I have a complete fuel circuit. Fuel does come out of the Schrader valve, but the pressure gauge I hooked up is reading zero PSI.
Thread Starter
|
Freshman User
Joined: May 2007
Posts: 37
Likes: 0
I think maybe the gauge is not working. I have fuel at the rail, and I just took the plugs out to check them and they were covered in gas. Cleaned them and put them back in. Now I'm waiting for the battery to charge back up from all the cranking I did so I can see if it'll run.
Trending Topics
New User
Joined: Jul 2013
Posts: 6
Likes: 0
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Thread Starter
|
Freshman User
Joined: May 2007
Posts: 37
Likes: 0
Well, the fuel pressure gauge I was using wasn't working, checked it on another vehicle that runs and got the same zero pressure reading. I did however find out what was causing it not to run...broken ignition rotor...couldn't see the forest for the trees. I guess I was so concentrated on the fuel issues that I wasn't bothering to look anywhere else. Thanks for the replies.
Thread
Thread Starter
Forum
Replies
Last Post
Piece of Kake
1987 - 1996 F150 & Larger F-Series Trucks
3
Apr 3, 2010 04:54 PM
INKAHOOTZ
1987 - 1996 F150 & Larger F-Series Trucks
2
Aug 26, 2009 04:41 PM
Primered86XLT
1987 - 1996 F150 & Larger F-Series Trucks
5
Mar 23, 2005 05:21 PM