QuestionI have a '95 Seville with the 4.6 Northstar, and the other day after taking my daughter to work a 63:30 AM with no problem, I parked it in the drive, came back out about 10:30 and it would not start. Turned over fine, so I checked the spark and it is firing okay. Checked the fuel pump fuses (both) and the relay, all seem to be good, with power going to the relay. Since the relay was the same part as the neighboring horn relay I swapped them out anyway, the horn worked fine on the suspect relay, so I put them both back in place. next I put my Schrader pressure gage on the fuel rail nipple, and it showed no pressure, so I pulled the fuel regulator off of the rail, and turned the key on, with no results. I did notice after awhile that there was a little bit of fuel in the regulator "bowl", but not enough to run out. Put it all back together for the night and went hunting for help. Can you? A few more details- the Haynes manual says to listen at the fuel filler door for the sound of the fuel pump when the key is turned on, but when I did I did not immediately hear anything, leading me to initially believe that the pump was the culprit, but after about 20 seconds or so I can here a pump running for about two seconds. My assumption was that at least the pump is running, but even with the regulator out, no fuel at the rail. Now since I am in Colorado and the temperature was about 20-deg.F, I thought that maybe I had some ice in the line, so i dumped a can of Heet into the tank, but of course cannot run the motor to circulate it very well. So I figured I would wait for it to warm up outside bit (I have no garage, working in the snow) which it did today, getting close to 50, but still no luck, no fire up. After all of this, I had one sneaky thought, and that's, am I actually hearing a suspension air pump coming on rather than the fuel pump? the sound is definitely in the rear, and all of my other air suspension vehicles had the pumps under the hood.
Thats it, Can you help? If so, could you respond to this address and my home at "shadowfax90@msn.com" as well? If I am at home it could help me get back on the problem sooner Thanks,
Garry in Colorado
AnswerWhen you turn the ignition switch to the ON position ONLY you should have full fuel pressure at the rail. Disconnect the fuel filter and see if you get quantity fuel. If NOT, Suspect fuel pump.
At the fuel pump relay you will see a RED wire that is not connected to anything. If you put battery voltage to this wire this will run the fuel pump constantly until you remove the battery voltage.
