Help! Falling fuel pressure...
 

My 72 RX2 will not hold fuel pressure. I'm running a street ported 13B with Demon carb and a Carter fuel pump w/regulator. The car starts and runs fine for a few minutes, but if left to idle, my FPG starts to slowly drop until the car stalls. If I drive the car, after a few miles it begins to choke and stalls.
I've tried everything from wiring the fuel pump directly to the battery, to bypassing the fuel tank completely using a 6 gallon drum of gas, and still no luck!! Please, if someone has encountered this before, help me out. Suggestions, ideas, or solutions will all be greatly appreciated.

Thanks in advance,
Gordon:(

perhaps you bought a faulty pump.

sometimes if your running semi-low pressure to start with, the regulators will fail. it happened all time last racing season when running 2 fuel pressure. if this is the case, you could either rebuild, as theres really nothing to them, or replace for cheap.

Just trying ot help here!!! It happened to me on my 86 celica.... After running a few minutes the car stalls... its like loosing fuel or air... I checked the pump and its ok... changd the filter, changed afm... But still stalls.... for the final attemp i changed my distributor (if you have one)... The problem is i got a faulty distributor and coil... check yours!!! After you stall... turn fo the engine and start it , is it ok again???

This will sound really stupid and impossible but replace your gas cap. I've seen a couple of carb'd cars have all sorts of problems that couldn't be solved conventionally but a new gas cap solved the problem since the old one didn't hold pressure. I can't explain it, don't understand it, and I wouldn't believe it if I hadn't have seen it. They are only a couple of bucks anyways so not much to lose.

Thanks for all the help but I am still chasing my tail. I have replaced the gas cap,I have replaced the fuel pressure regulator,I put in a new fuel pump,I put in a T and put in a return line to the tank and now have 1.5 psi so I restricted the return line with a clamp and now have 3 psi just enough to drive but have to be super careful not to lean out so drive with my eye on my air/fuel meters. Zlider thanks but my problem is fuel pressure related.:confused: :confused:

Have you tried re-doing the power wire to the fuel pump to make sure everthing is fine? It's the only other thing I can think of.