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Fuel Pump Primes but No ZERO Pressure

  • Thread starter Thread starter Lakecityg
  • Start date Start date Jul 11, 2018
L

Lakecityg

Member
Jul 11, 2018
4
2
13
Louisiana
Jul 11, 2018
#1
  • Jul 11, 2018
  • #1
Hey guys. I own a 92 model GT that I am restoring. Finally got the car running but yesterday while idling it just shut down. Tried to restart it and nothing. A few times it did fire ever so slightly, but now I get nothing. The pump does come on and sounds like it’s priming, but the car won’t fire. And there isn’t a single drop of fuel coming out of the Schrader valve. Also I did verify spark. Checked inertia switch as well and it is good. I reviewed the no start checklist here but it doesn’t mention this situation specifically...... I think. Another thing is when it was beginning to die I was trying to rev it up a little bit to keep it going and it responded like the gas pedal didn’t even exist. It didn’t pick up RPMs AT ALL. I am not sure what to look at next. Drop the tank and pull the pump? Would the fuel pump relay allow the pump to come on at all? Please advise. Thanks!
 

Steel1

Mustang Master
Aug 18, 2017
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Connecticut
Jul 12, 2018
#2
  • Jul 12, 2018
  • #2
Could the fuel filter be clogged?
 

General karthief

wonder how much it would cost to ship you a pair
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#3
  • Jul 12, 2018
  • #3
Go back to the 'cranks but no start checklist' start at the top and go step by step, the next step depends on the result of the one before.
Also, fuel filter change?
if you hear the pump running and no fuel pressure at schrader valve (using a gauge) there is the possibility the hose at the fuel pump in the tank has become dislodged or rotten and cannot pull up the fuel.
 
Last edited: Jul 12, 2018

Boostedpimp

20+ Year Stangneter
May 8, 2003
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Jul 12, 2018
#4
  • Jul 12, 2018
  • #4
Yeah I would start with replacing the filter. It's easy to get to and cheap. After that i would probably drop the tank and inspect the rubber on the fuel filter assembly for splitting and possibly the baffle broke loose and is restricting the pump inlet.

If you can hear the pump prime then I wouldn't think it was anything to do with the fuel pump relay
 
L

Lakecityg

Member
Jul 11, 2018
4
2
13
Louisiana
Jul 12, 2018
#5
  • Jul 12, 2018
  • #5
Boostedpimp said:
Yeah I would start with replacing the filter. It's easy to get to and cheap. After that i would probably drop the tank and inspect the rubber on the fuel filter assembly for splitting and possibly the baffle broke loose and is restricting the pump inlet.

If you can hear the pump prime then I wouldn't think it was anything to do with the fuel pump relay
Click to expand...

I will swap the filter. (Dang thing is brand new, but it could have caught crap). I will also review the list again. Just thought this situation was a little different being that the pump was actually coming on. Guess not. Back to the drawing board.
 

02 281 GT

Agreed...My wife has great Boobs
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Jul 12, 2018
#6
  • Jul 12, 2018
  • #6
I've heard of at least one instance where the soft line between the pump and the hard supply line developed a crack or a pin hole which would not allow the system to hold sufficient pressure to keep the engine running. The pump would prime and operate normally, but the break in the soft line would let the pressure bleed down.
 
Reactions: General karthief

Boostedpimp

20+ Year Stangneter
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#7
  • Jul 12, 2018
  • #7
Lakecityg said:
I will swap the filter. (Dang thing is brand new, but it could have caught crap). I will also review the list again. Just thought this situation was a little different being that the pump was actually coming on. Guess not. Back to the drawing board.
Click to expand...

Make sure the fuel filter isn't installed backwards while your at it

Also what I ment by my eariler comment about checking the pump assembly for splitting.. I ment check that "s" shaped hoes that connects the pump to the hanger assembly for splits.. because i've had it where my walbro pump was good but wasn't able to build up any pressure due to a crack in that hose. If that is the case replace the s hose with hose made to be in fuel
 
Last edited: Jul 12, 2018
Reactions: jrichker

Blown88GT

Founding Member
Nov 13, 1999
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Palm Beach Gardens, FL
Jul 12, 2018
#8
  • Jul 12, 2018
  • #8
Nothing at the schrader valve is no fuel pressure 26 year old pump needs a new one.
 

91TwighlightGT

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Sep 8, 2002
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Jul 12, 2018
#9
  • Jul 12, 2018
  • #9
Boostedpimp said:
Make sure the fuel filter isn't installed backwards while your at it

Also what I ment by my eariler comment about checking the pump assembly for splitting.. I ment check that "s" shaped hoes that connects the pump to the hanger assembly for splits.. because i've had it where my walbro pump was good but wasn't able to build up any pressure due to a crack in that hose. If that is the case replace the s hose with hose made to be in fuel
Click to expand...


I had this same experience on my car. The pump is running, but it just pumps the fuel right back into the tank.
 
L

Lakecityg

Member
Jul 11, 2018
4
2
13
Louisiana
Jul 12, 2018
#10
  • Jul 12, 2018
  • #10
This car has given me holy hell since the day I bought it. I have owned quite a few of these things but never fought one like this. Rant over. So I pull the tank. Not clean at all. Looks almost like there is residual oil or something in there. Anyway, not gonna fight that. New tank ordered. All of the connections at the pump look good but when I went to remove the fuel filter, not a single drop came out. Alsoin the past I remember having to catch some of the fuel from the lines as they hung down. Not this time. No fuel at all. So current status. Ordered brand new tank, new pump, new filter. I will put all of that back together Tuesday and see how it goes. Thanks for the help so far. I will Update you guys ASAP.
 

Blown88GT

Founding Member
Nov 13, 1999
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Palm Beach Gardens, FL
Jul 13, 2018
#11
  • Jul 13, 2018
  • #11
I'll bet someone put diesel fuel in the tank. The nozzle isn't supposed to fit, but they always find a way to do it.

My 25 year old tank looked like new inside. They put so many additives in fuel to keep the injectors clean, it keeps the tank clean, too.
 
L

Lakecityg

Member
Jul 11, 2018
4
2
13
Louisiana
Jul 14, 2018
#12
  • Jul 14, 2018
  • #12
Hey guys, new tank, new pump, new filter. Slapped it all in, and the car idles better than ever. Still have yet to drive it but it’s coming. Thanks for the help guys!
 
Reactions: Boostedpimp and General karthief
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