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Fuel Pressure Gauge

  • Thread starter Thread starter ARTTII
  • Start date Start date May 31, 2006
A

ARTTII

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Jan 13, 2004
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Detroit, MI
May 31, 2006
#1
  • May 31, 2006
  • #1
Where can I get a gauge to check the fuel pressure on the schraider (sp?) valve?

Also should I be looking for a guage to always leave on it or just to put on to test?

Thanks

93 lx 5.0
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
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129
May 31, 2006
#2
  • May 31, 2006
  • #2
The parts store should sell a diagnostic gauge for testing purposes.

For a permanent gauge, unless it's mounted on the cowl in a gauge suitable for cockpit mounting, it wont be a whole lot more useful than the diagnostic gauge. If permanently mounting one under the hood, I would not want one that is supported via the rail (mount it in a remote bracket). JRichker has some nifty info on whipping together a gauge if interested.

Good luck.
 
A

ARTTII

New Member
Jan 13, 2004
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Detroit, MI
May 31, 2006
#3
  • May 31, 2006
  • #3
OK thanks!

I will probably just go for the diagnostic gauge now. I'll check out NAPA and Autozone.

I'm trying to make sure I have adequate pressure (39psi) at the rail. Correct me if I'm wrong but when I take the reading it should be with the car off but pump running (as in grounding out the correct location on the STI plug)? Or does the car have to be idling to get a correct reading?

Right now the car won't idle, so I would prefer to take the reading with the engine off if possible. Also I have a vaccuum line hooked up to the regulator, this is correct right?

Thanks for the help
 
E

El_CUCUY

Member
May 1, 2006
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6
RGV
May 31, 2006
#4
  • May 31, 2006
  • #4
when i installed mine i tested it with the car on and yes keep the vacum line hooked up ....
Not to sure if you can test it with just priming the car
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
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129
May 31, 2006
#5
  • May 31, 2006
  • #5
ARTTII said:
OK thanks!

I will probably just go for the diagnostic gauge now. I'll check out NAPA and Autozone.

I'm trying to make sure I have adequate pressure (39psi) at the rail. Correct me if I'm wrong but when I take the reading it should be with the car off but pump running (as in grounding out the correct location on the STI plug)? Or does the car have to be idling to get a correct reading?

Right now the car won't idle, so I would prefer to take the reading with the engine off if possible. Also I have a vaccuum line hooked up to the regulator, this is correct right?

Thanks for the help
Click to expand...
Good call on the parts store diagnostic gauge. Some stores reportedly loan the gauges out (like they do specialty tools).

It would be nice to have the car running, but if that's not feasible, what you outlined sounds good. Leave the vac line just as it is - you're not setting fuel pressure - you just need to see if you have adequate pressure and the pressure reading with the vac line attached is lower than without the vac line attached (giving a better real world reading, given your situation). If pressure is below 30 PSI, that's not good. If you were to remove the vac line, you would want to see nearly 40 PSI.

You can simply install the gauge and let the pump prime during it's normal prime-out. You should have 30 PSI at the end of that priming. If you dont, continue to prime or jump the test connector to keep the pump running to see if you can build 30 PSI. As always, be aware of fire and safety concerns while doing this (I've had FP gauges leak before at the fitting).

There are several options depending upon your reading. If pressure is low, you can use fuel line crimpers (avl at the parts store) to carefully crimp the return line. If pressure magically goes up, the FPR is likely bad. This is NOT likely your issue.

Otherwise, post up and the smart folks in here can help out.

Good luck.
 

mob

the guy who hits on his mom
20+ Year Stangneter
Oct 3, 2003
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Dallas, TX
May 31, 2006
#6
  • May 31, 2006
  • #6
I think for like 20 bucks i got on at discount auto. Its not a permnant one, it came with a few different fittings and stuff, what a pain in the ass though, i ended up getting fuel everywhere and couldnt get the thing to fit on it right.
 

jrichker

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Jun 1, 2006
#7
  • Jun 1, 2006
  • #7
Fuel pressure gauge adapter fittings:
http://www.holley.com/products.asp?product=17945NOS AN 4 to 1/16” pipe
http://www.holley.com/products.asp?product=16785NOS 1/16” male pipe to 1/8” female pipe

Or
See http://www.autometer.com/cat_accessorieslist.aspx?pid=10

I made my own pressure gauge and holder. I bought the NOS or Autometer adapter that you screw into the place on the fuel line where the schrader valve goes. I ran a piece of SS (stainless steel) braided hose to a brass T fitting that I mounted on the fender well by the MAF. I made a mount bracket out of aluminum angle I got from Home depot and bolted it to the fender well. Then I mounted the brass Tee to it with some machine screws and a plate. I sandwiched the brass Tee between the aluminum angle and a flat piece of aluminum that I trimmed off the extra aluminum angle. Three screws laid out in a triangle pattern go through both pieces of aluminum to clamp the Tee in place. I used a cheap industrial gauge from MSC Direct (http://www1.mscdirect.com/CGI/NNPDFF?PMPAGE=4590). It works great and was cheaper than anything Summit had.

If you look through the MSC Direct catalog, you can find any type of gauge you want, including liquid filled. You only need a liquid filled gauge if you mount it directly on the engine. The liquid filling dampens out the vibrations.

You can buy the Autometer Stainless Steel braided hose for like $60. Or a local shop that makes hydraulic hose assemblies can make it for you at a cheaper price. Ordinary low pressure hydraulic hose can be used in place of the Stainless Steel braided hose, the Stainless Steel braided hose just looks nice. I got mine for $4 at a place that sells industrial and military surplus parts of all kinds. The Stainless Steel braided hose goes for about $3.60 a foot and the fittings are probably about $5-$8 each. You can make your own and save some $$$, the shops may have a setup or labor charge to fabricate the hose assembly.



 
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