Reg Issue or Fuel Pump?
01-02-2009, 09:22 PM
#1
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Reg Issue or Fuel Pump? Ive been having problems keeping the system at the proper psi. Ive got an aeromotive reg running off of the end of an edelbrock fuel rail. Then the return is out of the bottom of the reg to the stock line under the drivers seat.
My issue is this:
-once primed, system will not hold pressure, bleeds off once the pump shuts off.
-on a cold start, I get 50psi, after drive time the fuel pressure drops to about 30psi.
-fuel pump is a walbro 255 thats about 18mo old.
-when I attempt to adjust when sitting on 30psi, there is not response to adjustments made on the regulator (fuel pressure does not fluxuate).
-with the vacuum line off of the regulator makes no diff in pressure
Im reading this on a world products pressure gauge screwed into the regulator.
My issue is this:
-once primed, system will not hold pressure, bleeds off once the pump shuts off.
-on a cold start, I get 50psi, after drive time the fuel pressure drops to about 30psi.
-fuel pump is a walbro 255 thats about 18mo old.
-when I attempt to adjust when sitting on 30psi, there is not response to adjustments made on the regulator (fuel pressure does not fluxuate).
-with the vacuum line off of the regulator makes no diff in pressure
Im reading this on a world products pressure gauge screwed into the regulator.
01-03-2009, 08:56 PM
#4
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You shouldn't be having the high pressure on cold start issue. Have you pulled the fuel rail off to check for leaking injectors?
The only reasons you should have a problem adjusting the pressure (if you are adjusting correctly) would be if there is a problem with the spring/diaphragm/set screw or if you're leaking enough from your fuel rail that the regulator can't maintain the pressure on the rail. The set screw AND vacuum line not making any difference sure make it seem like it's the first, and the diaphragm isn't moving at all.
You are adjusting it while the engine is running correct? I'm just making sure, but I assume you are as you said the pressure bleeds off instantly with pump shutoff.
Is there any reason you can't hook up another gauge off the rail, just to double check the gauge off the fpr?
Edit- My comments were completely based on the fuel pressure regulator. If I get a chance I'll post anything I can think of about the pump tomorrow.
The only reasons you should have a problem adjusting the pressure (if you are adjusting correctly) would be if there is a problem with the spring/diaphragm/set screw or if you're leaking enough from your fuel rail that the regulator can't maintain the pressure on the rail. The set screw AND vacuum line not making any difference sure make it seem like it's the first, and the diaphragm isn't moving at all.
You are adjusting it while the engine is running correct? I'm just making sure, but I assume you are as you said the pressure bleeds off instantly with pump shutoff.
Is there any reason you can't hook up another gauge off the rail, just to double check the gauge off the fpr?
Edit- My comments were completely based on the fuel pressure regulator. If I get a chance I'll post anything I can think of about the pump tomorrow.
Last edited by RoAdRaGe912; 01-03-2009 at 09:00 PM. Reason: fpr only
01-03-2009, 09:25 PM
#5
The aeromotive is hands down the most failure prone regulator alternative for the LT1. On the plus side they don't seem to be so bad as to burn down cars ANY MORE but that used to be the case.
They bleed down fast after shutdown and have claimed it is intentional so as to not leave the fuel system pressurised when not needed.
Since you say Edelbrock rails and such can I guess your's is not a "stock style" regulator?? Still with Aeromotives LT1 track record that would be the part I would focus on for now.
They bleed down fast after shutdown and have claimed it is intentional so as to not leave the fuel system pressurised when not needed.
Since you say Edelbrock rails and such can I guess your's is not a "stock style" regulator?? Still with Aeromotives LT1 track record that would be the part I would focus on for now.
