fuel PSI troubles

[Cratos]

hi gang I have a fuel psi issue

history

restored with all new tank, lines Pumps (both caters electric in the back and HP up front)

Aeromotive filter before reg feeding a fairly stock 383 six pack

with just driving a round I can see the PSI drop and come up ( autometer gauge) if I get on It, it drops off quickly ( sometimes the motor stalls out like its out of fuel ) I pulled the filter and it was clean, dropped the line into a bucket fuel flows fine ( about 1 quart+ in 20 -30 sec)

reg is set at 6 psi

Any Ideas?? Only other thing I can think of is strainer on the pick up is collapsing??

 

[Adam]

Restrictive regulator? Can you bypass the regulator, use a gauge, and see what kind of pressure & flow you have; Obviously you don’t want too much. But if getting a lot of flow you will know the fuel tank sock is not collapsing.

 

[AUSTA]

Is the pump voltage staying steady ,you would think the bucket test would prove the system if the the pickup was to collapse it would do it at full flow into the bucket.
Is that with a good amount in the tank its not the fuel sloshing to the back & starving the pickup
Silly question are both pumps installed with the correct flow direction.

 

[Cratos]

It does not do it in till you are driving a bit

Pump sound does not change it is one of those cheap Holley regs should have spent the 125 for the Aeromotive one. Getting 6 psi, I will pull the line after the reg, to see if it is dropping there, tomorrow.

 

[AUSTA]

Have you tried to loosen the fuel cap is it vented could be pulling a vacuum

 

[Cratos]

the tank has the external vent line ( it is new also) but ill look into it.thanks

 

[moparleo]

What location did you mount the rear pusher pump in " Below the tank level where it should be or high on the subframe where it shouldn't be. And what was the reason for 2 fuel pumps on a "stock" engine ?? Future plans ?

 

[Cratos]

only place I could put it is on the crossmember in front of thee tank above the rear end
second pump was to cure the extra cranking needed when the motor is hot.I will try bypassing the front pump, tomorrow, to see if that helps.

 

[70chall440]

I once had a similar issue wherein I had a Holley electric in the back and a HP mechanical in the front, I discovered that the electric pump wasn't keeping up with the demand of the mechanical, in other words it was acting as a restriction under acceleration.

 

[moparleo]

You need to relocate the electric pump. It can and must be located elsewhere. It needs to be as low as possible and have a good fuel filter between it and the tank. If you are not sure how to do this, look at a few YouTube videos as well as check the website of the pumps manufacturer to get instructions. Vapor lock is prevented by using and electric pump to Push the fuel down the fuel line from the tank as opposed to pulling or suction on the fuel line by a front mounted pump, be it mechanical or electric. The best setup is an intank mounted electric fuel pump. It solves all mounting and plumbing problems. It also negates the need for the mechanical pump. These are available now.

 

[AUSTA]

I once had a similar issue wherein I had a Holley electric in the back and a HP mechanical in the front, I discovered that the electric pump wasn't keeping up with the demand of the mechanical, in other words it was acting as a restriction under acceleration.

Yes that make sense

 

[Cratos]

I pulled the electric out of line and still having psi loss I have a new Aeromotive regulator on the way I think the cheep summit one may be the culprit.

 

[70chall440]

Its called "discovery learning"... LOL we all have been there (and go back there time and time again)...

 

[Cratos]

yea I need to get this fixed, next week I start the a-body rear swap so my tires fit the fender wells and I can ditch the air shocks!!!

 

[70chall440]

Just take it methodically and in an organized fashion and you will figure it out. We all like to hit the "easy" button but there are so many variables it is hard to diagnose on a forum, good to get some ideas but ultimately it will be your brain and work that fixes it.

Start at one end or the other and start checking things out, make sure you confirm that each item is good before moving on.

 

[moparleo]

https://www.jegs.com/InstallationInstructions/500/510/510-12-801-1.pdf
Electric Fuel Pump: How to Do It Right
Mounting an electric fuel pump

 

[Cratos]

any photos of the pump mounted low in a challenger? just looking there is not much room between the tank and rear end.

 

[moparleo]

Mount it as close as possible. Mount it to a frame rail and then run a braided fuel line to it. Frame rails similar between car brands. The tank is still in the same place and the rear end is still a rear end. It won't be perfect because it wasn't designed to be there in the first place. In tank pump is the easiest/best situation that you could hope for. You don't have to modify anything or worry about clearances. If it is money, just save up a little more and then sell the one that you are not going to need anymore. Driving your car and not having to worry anymore would be worth it to me.

 

[Cratos]

It looks like it will be hitting the rear end if I mount it towards the bottom of the tank

 

[Cratos]

ripping out the tank and going Areomotive gen 2 set-up that will fix it!!