Pre filter in mech pump?

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Hipo65

Hipo65

Yeah I'm "That Guy"
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Hey guys been chasen a fuel starvation issue on my little 65 dart. heres the list,new tank sending unit,stock replacement mech fuel pump & i have recently added a holley red lable back by the tank & she still seems to run awsome then falls off then comes back falls off comes back ex ex. ive blown through the line & no restrictions. My qustion is do those stock replacement pumps have a filter/screen in them? im runnen outta ideas. Oh & the screen is outta the carb to.:banghead::banghead:
 
Have you checked the fuel pickup in the tank? The sock is probably stopped up with crap.
 
yes sock is gone from sending unit, & i thoufght F-it i took off the pump & cut the bottoms off & there is brass screens on both sides,but they didnt have hardly any thing in them???? man theres no way my little 273 is out doen the stock fuel system. the holley is mounted to trunk floor right above rear diff its an older pump but worked well on my old 318. ideas???
 
Make sure the bowl vent is opening. If you have a air lock and cycling a air pocket back and forth from carb bowl to fuel filter, you could see it happen when using one of the clear plastic filters up in front of the carb.
 
Confirmed the screen is clear even in the eletric pump, what do you mean by bowl vents opening? its the o.e. carter afb on it the bowl vents are allways open. I am useing a clear plastic filter for whatever thats worth.
 
The bowl vent is not effing going to cause the pump pressure to drop.

You need to concentrate on the delivery TO the carb. You KNOW it's dropping fuel pressure, so find out why.

Hell, could even be a bad pump.

Look in the shop manual..........there are figures in there for rated GPH. Holley undoubtedly has the same info. Google around the tech pages and find out how Holley rates their pumps

If you can't find out, "assume" that it should deliver AT LEAST as much as a factory pump. Disconnect the line at the carb, leave your gauge hooked up. Rig a valve so you can throttle the output. Throttle the valve to reach a minimum pressure, say, 3 psi and see what kind of volume you are getting over so much time.

!!!DOH!!! Guess what!!!! It's right on the page I posted earlier

https://www.holley.com/12-801-1.asp

71 gph at 4psi, so that's about 1.2 gallons per minute, or .01972 gallons per second. So, if you operated the pump, throttled to 4psi for 10 seconds, that is .19 gallons, IE almost a quart, 20 seconds is .394 gallons so damn near 1/2 gallon in 20 seconds.
 

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I knew the 4psi & free flow specs on the red years ago my freind! (hence the reason i got it in the first place & cured the starvating issue with my old 318!) thats what confused me to begin with! Once the snow is cleared enoph :mumum: around here ill just bypass the mech all together & see if that helps. ive been also thinken of a bigger/better carter mech (hate the rrrRRRrrrRRRrrrRRR of the noisy a$$ ele) I know what each pump "should" do im just not seeing anything blatenly staring @ me saying here i am! the red seems to be flowing a fair ammout bypassing the mech for sure so hope warmer weather gets here soon to see if the mech is just not good enoph.
 
Sorry. Mine is a 2 brl. Its bowl vent opens only if the accl' pump returns all the way to the top. I did have the same symptom. Line pressure wasn't the problem.
Good luck with it.
 
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