How to test the fuel pressure?

Tiny
KAPITON121
  • MEMBER
  • 1995 FORD F-150
  • 4.9L
  • 6 CYL
  • 2WD
  • MANUAL
  • 1,550 MILES
Truck will stop at read lights and stop signs. After about thirty minutes it will start and run for about ten minutes and stop running again. I have no way to test the fuel pressure. The fuel rail does not have a test port. I fixed a broken wire under truck and I got the odometer started working. I just don’t know we’re to start.
Monday, July 26th, 2021 AT 6:51 PM

8 Replies

Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
You are correct that there is no traditional schrader valve to connect a gauge as shown in this guide. This requires a special tool to hook up the gauge to the pressure relief valve.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Please run through the testing and info below and let us know if you have questions on this. Thanks
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Monday, July 26th, 2021 AT 8:06 PM
Tiny
KAPITON121
  • MEMBER
  • 4 POSTS
  • 1995 FORD F-150
  • 4.9L
  • 6 CYL
  • 2WD
  • MANUAL
  • 155,000 MILES
The truck will shut down at stop lights and stop signs, after a bit it will start back up until you hit another light or stop signs. It never started doing this until I found a broken wire and repaired it. What could be the problem?
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Wednesday, July 28th, 2021 AT 3:39 PM (Merged)
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
Good afternoon,

The test port is on the fuel rail. You can rent the tester at a parts store.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Key On Engine Off 50 - 60 PSI
Key On Engine Running 45 - 60 PSI

Check the spec with the key on.

Roy
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Wednesday, July 28th, 2021 AT 3:39 PM (Merged)
Tiny
KAPITON121
  • MEMBER
  • 4 POSTS
The 4.9 Ford does not come with a test port. So what else can I do? None of them do I have tried to get one at the junk yards. Please check this out. Now what else can I do?
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Wednesday, July 28th, 2021 AT 3:39 PM (Merged)
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
Then you have to break into the fuel filter and install a T in the line. That comes with the test lit you can rent.

Roy
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Wednesday, July 28th, 2021 AT 3:39 PM (Merged)
Tiny
KAPITON121
  • MEMBER
  • 4 POSTS
Here in Florida none of the parts houses have nothing to rent to check the fuel pressure. I have tried to rent it but the parts stores have any thing like that.
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Wednesday, July 28th, 2021 AT 3:39 PM (Merged)
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
You can get a cheap kit at Harbor Freight.

Roy
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Wednesday, July 28th, 2021 AT 3:39 PM (Merged)
Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
Hey Kapiton,

I got your message. I think we may be on different pages with the way we are describing this.

I think we are agreeing that there is no Schrader valve on the rail but the way in which Ford has you check the pressure is by removing that relief valve and install the tool number that is listed in the attachment below.

Or you can do what Roy suggested which is just open the fuel line somewhere else and put in "T" and attach the gauge to it there. General kits from any parts supplier will have what you need to do it this way.
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Wednesday, July 28th, 2021 AT 4:46 PM

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