What type of symptoms did the car have when the line was restricted?
Fuel Pressure - Does not change (w/ or w/o vac line)
- Thread starter onebad7up
- Start date
What type of symptoms did the car have when the line was restricted?
Its been about 10 years, but IIRC I was rich at idle, fuel pressure was stuck in the 45-48 regardless of the regulator adjustment. I did not have it tagged yet to drive it on the road. I cut the fuel line just in front of the passenger side rear wheel well, just before it snakes up behind the rear seat area. I blew air from the line at the rail to the cut I made and no restriction. I then tried to blow air from the cut to the tank and bingo....it was somewhere where the line snakes up to the tank. I just rain the rubber hose from the cut location to the sender until I got my S/S lines.
If you don't want to cut the line, just find a fitting that you can screw into the return port on the rail, then run a hose into a fuel jug or with a longer rubber hose back to the tank filler neck. You only need to run the car long enough to see if it corrects the problem.
If you don't want to cut the line, just find a fitting that you can screw into the return port on the rail, then run a hose into a fuel jug or with a longer rubber hose back to the tank filler neck. You only need to run the car long enough to see if it corrects the problem.
Last edited:
- Joined
- May 28, 2001
22 posts to this thread, and no reply from the op as to removing the valve stem??? [Post #13]
If you want help, suggest you reply to the suggestions/questions...just sayin....
If you want help, suggest you reply to the suggestions/questions...just sayin....
I didn't respond to this suggestion because I already ruled this out. The tester has a bleed port and pressure returns to the 39-40psi after discharging. The fuel pressure is making it past the shrader valve.
- Joined
- May 28, 2001
Are we supposed to be mind readers? I asked about such a provision on the gauge.
Good luck...
Good luck...
1986 Buick GX1
GX1 #001 [The One and Only]
- Joined
- Apr 24, 2015
I was hoping it was a simple resolution like pulling the shrader valve as well. Seems that 99% of the gauges out there need the shrader valve removed, I know mine does.
It should drop. The reason it doesn't is because the return line can't flow the excess fuel,sent to the engine by the pump,back to the tank. The fuel pump always operates at maximum output,so at an idle it has to send a lot of unused fuel back to the tank. It is at this time that the volume of fuel traveling through the return line is at its highest amount. The bigger the pump,the bigger/less restrictive the return line needs to be because the same engine uses the same amount of fuel at idle and would therefore need to send a greater volume of fuel through the return line back to the tank. There are five things you can do.
1. Turn the pressure up until you are able to see a 5-7 lbs drop when vacuum line is removed-not recommended.
2. Find and remove a restriction in the return line. The rubber hoses above the tank can get pinched and drilling the two Saginaw fittings in the return line to a larger diameter can help.
3. Replace the return line with one of a larger diameter.
4. Remove the hotwire and return the wiring to stock to slow down the pump.
5. Install a pump with a lower output volume.
- Joined
- May 27, 2010
After reading this I have to agree return line is kinked somewhere causing the pressure to increase. Or you have a small fuel leak at some point. I also have heard of this symptom when replacing with larger fuel pumps and adding a Hotwire kit! Since we have no info on mods and what else has been worked it quite pointless to ask. Better find someone local that can help you out or just contact one person and go from there.
Sent from my iPhone using Tapatalk
Sent from my iPhone using Tapatalk
