Having a terrible time trying to get fuel pressure to set and stay at 3 psi to flathead ford v8 with dua carbs , help!
Which regulator are you using? Malpassi has a fuel filter and regulator that's 1-7psi. Hard to get in the states, but used for Webers in the VW world.
Holley adjustable 1-6 psi, set it at 3 psi but keeps going to 1 psi on mechanical pump 1946 model 59 an engine then it won't adjust any higher
Speedway carbs on the 97 style ,have tried 2 different mechanical pumps and also tried a Holley ,variable 1-6 psi with same effect , tank cleaned and coated,all new lines with 2 fuel filters in the system ,set to 3 psi then drops to zero after a minute or two of run time ,then I cannot get pressure to increase
With that statement it’s obvious you have a blockage somewhere. Install your pump and regulator near your tank. The blockage could very well be at your tank, line , filter or regulator. Maybe something came off your new tank lining??
Petejoe, has some good suggestions. Also: Disconnect the fuel line at the carb, turn on the pump and actually see how much gas is being pumped to your carbs. Also: Would it be possible to by pass the regulator and have the pump send the gas directly to the carbs? Also: Is the diaphragm in your regulator faulty? Is it leaking? Take your regulator apart and check for cracked diaphragm. Finally: It has been noted on Fordbarn that the viscous filled fuel pressure gauges mounted in the engine compartment often drop to ZERO reading due to the engine heat. When I emptied the fluid from my engine compartment fuel pressure gauge I obtained more accurate readings. The needle movement fluctuated so I added a small amount of brake fluid to the gauge without filling it. There was improvement.
If you have a filter before the pump, you might try bypassing it. It's possible it could be restricting flow to the pump.
After dealing with fluctuating fuel pressure with my Aeromotive 0-15 lb. regulator I learned that the problem may be with the gauge and not the regulator. I found this article on the subject which may be of some help to you: https://aeromotiveinc.com/new-standard-fuel-pressure-gauges/
I did blow air pressure through the line to the tank with cap still on and the back pressure sent a big stream of fuel back to me at the carbs , checking for blockage
I hadn't tried moving the electric pump close to the tank yet to push fuel instead of pull ,and what Gage is recommended at the carbs ,1-15 oil filled or dry or other ones
Dickster sells a low pressure gauge here in the classifieds. Anything with a large range won't be accurate when you are trying to measure clear down on one end of the scale. I also agree that the pump should be as close to the tank as possible.
It starts missing badly shortly after idle like it's starving ,idle is great ,but always misses at hard acceleration, engine is new rebuilt 60 over on bore,max 1 cam,pertronix electronic in crab ,with hot coil ,new wires,cap
The speedway 97s have not gotten the best reviews, make sure the accelerator pump is giving the "shot" you need. Might need to completely disassemble and check for debris.
In our racing application ( northeast bigblock modifieds) many of us have had trouble with any sort of " deadhead " pump or regulator. When a pump of greater volume and pressure than could ever be required and a " bypass" style regulator which returns the excess fuel to the tank is used WAY fewer fuel pressure/delivery issues are encountered.
I had a similar problem with the same symptoms as you have. I found my front carb inlet had a bunch of debris in it. The front carb bowl would run out of gas after awhile and the motor would run on just the back four cylinders. Unscrew the tops of the carbs so you can see the float bowls, blow air in the inlet( don't spray fuel everywhere) to the carbs to make sure the inlets are not clogged. Hook up your fuel lines again and turn on your fuel pump, see if both float bowls are filling up. If both fill up, put it all back together and try it.
Here's an update on my fuel pressure problem, I moved the electric fuel pump and mounted It on the frame about 12 inches from the fuel tank outlet with a 100 micron filter between them , wired through a relay to the starter switch and ground wire directly to the battery ground, turned the key on and got 9 psi on both the carbs gages, adjusted the regulator down to 3 psi recommended for the speedway 97 knockoffs , and started right up ,didn't get a road trial in due to heavy rain today, but gages only fell to 2 psi after heated up , will know more Monday after road trial ,thanks to everyone for the helpful information, was a Lotove good help.
I think your fine in the 2-3 range. If a guy had a return line back to the tank that had a .030 orifice in the hose, the pressure would bleed off right after the pump shots off, and would eliminate any heat soak boil overs. I'm planning to do that with my Webers.
My biggest beef about it all is I bought 2 different new fuel pumps ( mechanical) made in China junk and neither would give me more than 1 psi , the quality comming across the pond is awfull, so if you run mechanical I suggest having it built by a specialist in the USA or rebuild it yourself with quality parts.
I used an old stromberg jet, and threaded the ID of a brass fitting to accept it. You can soldier the hole shut and drill it whatever you want.
I don't know anything about Speedway Super7's except what I've read on the internet. But if they think they behave anything like a Stromberg does, they should have 2 pounds maximum. My real Strombergs behave best with 1.5 pounds at the gauge on the firewall.
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