View Full Version : LT1 swap into Chevelle - no fuel pressure
aarroyo87
09-28-2009, 08:24 PM
I'm doing my initial start up and I have no fuel pressure. I hear the fuel pump when I turn the key but no pressure at the fuel rail. My fuel system consists of the following:
Spectra EFI fuel tank
1995 Chev Caprice fuel lines
stock fuel pressure regulator
5 gallons of gas in tank
I have a couple ideas of what the problem might be but I have some questions.
Are the Chevrolet nylon fuel lines directional? Meaning fuel can only go a certain direction?
I've heard of Spectra fuel tanks having the fuel pump wire incorrectly. Has any one had this problem and know how to fix it?
Any help or suggestion are appreciated.
-Albert
aarroyo87
09-28-2009, 10:05 PM
"I got one of these Spectre tanks from Rock auto about the same time and just got it installed last week. Mine wouldnt pump fuel either, but i could hear the pump running. So i pulled the sending unit then the pump itself. I put the pump in water (to prevent a fire) and jumped wires to it (correct polarity) and low and behold it shot water about 8 inches. Next step was to check the polarity with a multimeter on the plug and sure enough, the 4 prong connector (grey) under the sending unit assy, had the wires crossed for the pump. THis caused it to spin backwards and not pump fuel. I pulled the lock out of the plug and pushed the pins out with a paper clip and corrected the polarity. Verified the sending unit polarity also. It was ok, so perhaps the person wiring these units had a bad day or few days and obviously these units arent tested before shipping. So after wasting a couple of hours troubleshooting the thing, flushing the pump and lines, the fuel pressure hit 58 psi and fired right up.
As far as your sending unit problem, pull the sending unit/pump assy and hook your meter to the sending unit wire (purple) and ground. Move the float assy up and down and measure the ohms. Also check to make sure that the float isnt obstructed in any way, it must float freely in the tank. If something is not allowing it to go down with the fuel level, it will cause the gauge to stick. This is the third component in this LS swap in a 67 Camaro that has not worked and needed modification or troubleshooting. Fun stuff..."
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