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shawn1648 · 11-05-2009, 09:55 PM

I got one of those fuel pressure testers today at the auto store because I didn't have one and one of the first questions you guys always ask me is...have you tested the FP? I want to be able to have an answer to that from now on.

I also got a vacuum tester for the same reason.

Can someone walk me through how to use them? They are both by Actron. I searched and didn't find anything clear after about 20 minutes.

***jopes*** · 11-05-2009, 09:57 PM

http://www.secondchancegarage.com/public/186.cfm

the vacuum guage should have came with instructions.

the fuel guage goes on the fuel rail. turn the key to on watch the guage. it should go up. then you can start it, with the vacuum line off you should have 39.5psi per ford.

shawn1648 · 11-05-2009, 10:11 PM

Thank you!

It does. But which hook up location for the vac guage will give me the best results? Should I also try multiple locations?

***jopes*** · 11-05-2009, 10:11 PM

between the heads and thottle body. you want full manifold vacuum.

shawn1648 · 11-05-2009, 10:15 PM

So I should hook it to the place where the brake booster line goes into the intake?

**SigEpBlue** · 11-05-2009, 10:18 PM

It doesn't matter. For all practical diagnostic purposes, manifold pressure is the same throughout the entire manifold.

shawn1648 · 11-06-2009, 08:54 PM

Fuel pressure is reading 31psi at idle.

I'm not sure if I did it right. I unscrewed the cap on the shrader valve. Screwed on the adapter. Screwed in the fuel gauge and hose assembly and placed the tube in a container. I turned the key so the fuel pump turned on, checked the gauge, it wasn't reading anything. I started the truck and the fuel pressure gauge went up to just a hair over 31. Let it idle for awhile, no change. I turned off the truck and the gauge dropped back down to zero. No fuel in the tube or container. No leaks around the valve or brass fittings.

**SigEpBlue** · 11-06-2009, 08:59 PM

Pull the vacuum line off of the fuel pressure regulator (it'll be a red line with a 90� rubber elbow on the end going into the regulator) and stick a golf tee or similar object into the rubber connector to plug it. With the engine running, and that vacuum line plugged, your gauge should read ~39psig. 31psig @ idle sounds about right.

shawn1648 · 11-07-2009, 09:24 AM

FP is 41.5 with the vac line plugged.

**SigEpBlue** · 11-07-2009, 01:14 PM

11-05-2009, 09:55 PM	#1
shawn1648 Registered User Join Date: Jan 2009 Location: Maryland Posts: 107 iTrader: (0) Bronco Info: 1992 FSB 5.8L shawn1648s Garage	Fuel pressure and Vacuum test I got one of those fuel pressure testers today at the auto store because I didn't have one and one of the first questions you guys always ask me is...have you tested the FP? I want to be able to have an answer to that from now on. I also got a vacuum tester for the same reason. Can someone walk me through how to use them? They are both by Actron. I searched and didn't find anything clear after about 20 minutes.

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Fuel pressure and Vacuum test

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11-05-2009, 10:11 PM	#3
shawn1648 Registered User Join Date: Jan 2009 Location: Maryland Posts: 107 iTrader: (0) Bronco Info: 1992 FSB 5.8L shawn1648s Garage	Thank you! It does. But which hook up location for the vac guage will give me the best results? Should I also try multiple locations?

11-05-2009, 10:11 PM	#4
*jopes* balls deep with my Join Date: Feb 2003 Location: Maggie's Nipples, Wyoming Posts: 13,162 iTrader: (3) Bronco Info: pile of parts jopess Garage	between the heads and thottle body. you want full manifold vacuum.

11-05-2009, 10:15 PM	#5
shawn1648 Registered User Join Date: Jan 2009 Location: Maryland Posts: 107 iTrader: (0) Bronco Info: 1992 FSB 5.8L shawn1648s Garage	So I should hook it to the place where the brake booster line goes into the intake?

11-06-2009, 08:54 PM	#7
shawn1648 Registered User Join Date: Jan 2009 Location: Maryland Posts: 107 iTrader: (0) Bronco Info: 1992 FSB 5.8L shawn1648s Garage	Fuel pressure is reading 31psi at idle. I'm not sure if I did it right. I unscrewed the cap on the shrader valve. Screwed on the adapter. Screwed in the fuel gauge and hose assembly and placed the tube in a container. I turned the key so the fuel pump turned on, checked the gauge, it wasn't reading anything. I started the truck and the fuel pressure gauge went up to just a hair over 31. Let it idle for awhile, no change. I turned off the truck and the gauge dropped back down to zero. No fuel in the tube or container. No leaks around the valve or brass fittings.

11-06-2009, 08:59 PM	#8
SigEpBlue Satyr of the Midwest Join Date: Nov 2005 Location: Ida & Grand Rapids, Michigan, a.k.a The Unemployment Capital of America Posts: 14,529 iTrader: (2) Bronco Info: 1993 EB, 5.8L, BIO0 MAF, GT40Ps, Mustang cam, GT40 Intake, Custom Headers, Moates QuarterHorse Blog Entries: 1 SigEpBlues Garage	Pull the vacuum line off of the fuel pressure regulator (it'll be a red line with a 90� rubber elbow on the end going into the regulator) and stick a golf tee or similar object into the rubber connector to plug it. With the engine running, and that vacuum line plugged, your gauge should read ~39psig. 31psig @ idle sounds about right.

11-07-2009, 09:24 AM	#9
shawn1648 Registered User Join Date: Jan 2009 Location: Maryland Posts: 107 iTrader: (0) Bronco Info: 1992 FSB 5.8L shawn1648s Garage	FP is 41.5 with the vac line plugged.

11-07-2009, 01:14 PM	#10
SigEpBlue Satyr of the Midwest Join Date: Nov 2005 Location: Ida & Grand Rapids, Michigan, a.k.a The Unemployment Capital of America Posts: 14,529 iTrader: (2) Bronco Info: 1993 EB, 5.8L, BIO0 MAF, GT40Ps, Mustang cam, GT40 Intake, Custom Headers, Moates QuarterHorse Blog Entries: 1 SigEpBlues Garage