Fuel pressure leakdown
Thread Starter
Racer
Joined: Sep 2005
Posts: 304
Likes: 1
From: Carson City Nevada
Fuel pressure leakdown
Does this seem normal to you for an 88? Runnning pressure, 40psi. Ignition off, 45psi. After ten minutes, 40psi. After 20 minutes, 22psi. After 30 mnutes, after an hour, 16psi. Anyway, the reason I am checking is I smelled fuel when I pulled #5 and #6 plugs. the pressure looks ok to me, but I am no pro.
Last edited by 87FIREREDRAGTOP; Feb 12, 2012 at 05:57 PM.
Safety Car
Joined: Jan 2004
Posts: 3,556
Likes: 13
Does this seem normal to you for an 88? Runnning pressure, 40psi. Ignition off, 45psi. After ten minutes, 40psi. After 20 minutes, 22psi. After 30 mnutes, after an hour, 16psi. Anyway, the reason I am checking is I smelled fuel when I pulled #5 and #6 plugs. the pressure looks ok to me, but I am no pro.
Can always confirm if injectors are leaking by clamping both fuel lines after building pressure and see if pressure drops at same rate
Pro
Joined: Aug 2010
Posts: 617
Likes: 17
From: Hamilton Ontario
Something is leaking in order to bleed down that fast...can't see it being by design, but im no expert for sure...........
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Racer
Joined: Nov 2006
Posts: 420
Likes: 0
From: Sierra Madre California
Pull your throttle body off (2 minute job) and look inside of the plenum. If there is raw gas in there, it is your fuel pressure regulator diaphram leaking.
Fairly easy fix. You can replace it without taking the regulator off. Just remove the plenum; the regulator is between the fuel rails at the rear. It is simply matter of removing 6 or 7 screws, putting the new diaphram in, and puting the screws back on. Just make sure that you tighten the screws carefully so that you don't wrinkle the diaphram. 30 minute job if you're experienced; 1 to 1 1/2 hrs if you take your time.
Fairly easy fix. You can replace it without taking the regulator off. Just remove the plenum; the regulator is between the fuel rails at the rear. It is simply matter of removing 6 or 7 screws, putting the new diaphram in, and puting the screws back on. Just make sure that you tighten the screws carefully so that you don't wrinkle the diaphram. 30 minute job if you're experienced; 1 to 1 1/2 hrs if you take your time.
Last edited by jesredvette; Feb 14, 2012 at 11:30 PM.
Thread Starter
Racer
Joined: Sep 2005
Posts: 304
Likes: 1
From: Carson City Nevada
Stock regulator. No fuel in the vacuum line. Didn't see it as a problem. I did find some coolant on the manifold around #7. Guess I am doing a intake gasket...
Last edited by 87FIREREDRAGTOP; Feb 15, 2012 at 09:11 AM.
Thread Starter
Racer
Joined: Sep 2005
Posts: 304
Likes: 1
From: Carson City Nevada
Well, looks like I have a leaker. Pulled the fuel rail and injector assy, pressurized it and number 5 is dripping. I just ordered a reman set from FIC. Hope I caught it before it did any damage to the rings.
