I let my car run for like 10 minutes at idle, it starts at 7 psi and steadily drops after 10 minutes at idle to like 2 pounds.. Anyone have any suggestions?

Fuel Check Valve?

When was the last time you changed it?

Hell, when was the last time I changed mine? ...I need to check on that.

What is the fuel check valve? This is everything I did to it. I have a carter fuel pump and ran 3/8 inch hardline to my carb and 3/8 inch rubber tubing into the pump and still nothing after it gets warm. Could it be the pump?

Thats a good pump, if its not very old, I wouldnt think thats the problem. Find out what the GPM(gallons/litres per minute) is on it and test to see if it is putting out the same amount after the pressure goes down. Is it running any different?

The fuel check valve is the metal looking thing on your return fuel line, its supposed to keep the fuel from just running straight through the carb and back to the tank through the return. There is an arrow on it that should be pointing towards the carb. To check it, take it off and blow through the valve in the opposite direction as the arrow is pointing.

Has this been happening since you changed the fuel lines? If you didnt put this(check valve)back on that may be the problem. Let me know if it helps, Im curious.

My carb doesn't have a fuel return line, so there isn't anything flowing back to the tank. The car runs ok up to about 4000 rpms and then stops pulling and it idles fine for a while then dies.

yah thats so weird. you could maybe hook up a voltmeter to the pump and see if the voltage at the pump changes over time?



mike

I might try that. BUt I am getting so sick of not being able to drive my car. I really want to see what this set up can do.

I have the same problem but with a rx2. I put a relay and wiring to my pump to make sure it had enough voltage. I changed pumps went to a aeromotive, got bigger lines, larger filter, ran a return line or I couldn't adjust the regulator. After I ran mine for approx 35 minutes the pressure started dropping and the pump started making noise. Called aeromotive and they tell me the pump is cavitating because the fuel is getting hot and my return and my line out of the fuel tank are too small. I am bought new 3/8 aluminum line to run under( I have 3/8 line in the motor compartment only)the car to the tank and also back to the front. I have gone so far as to talk to a company about making me a fuel cell. I can feel your frustration and I work at a car dealership.I have changed pumps,regulators,fuel line,gas cap, vent lines both removed and reinstalled. at one time I ran a line directly to the carb with a return line(dead head) and no problem then all of sudden I started running out of fuel. Nice to know that I'm not the only person having this problem I will keep you informed and please if you find out let me know. https://www.nopistons.com/forums/pub...1047683358.gif

mazdatrix just told me to buy a new pump, which I just did, maybe that is the prob.

The more you guys talk the more it sounds like you need fuel pumps with alot of volume. Stock is only about 4.5 lbs at more than 1.16 liters per minute.