fuel pressure issues

[hupertracing24]

ok here is the situation, put in brand new fuel cell at begining of year been running most of the season all of a sudden the fuel pressure is bouncing all around going down the straight away and drops to real low with the light coming on. replaced the pump which was a carter 170gph. put a new one on still same thing. pressurized the system holds air no leaks, pulled the top of cell to check the pickup no cracks. tore the pump back off checked the push rod this is what i found, the rod was tappered .020 from one side to the other and is .035 shorter than what is should be. ordering a new rod, pulling my hair out with this does this seem like it would be my problem. forgot to mention that at idle it works just fine it just under high rpms any help would be great , thank you

[billetbirdcage]

ok here is the situation, put in brand new fuel cell at begining of year been running most of the season all of a sudden the fuel pressure is bouncing all around going down the straight away and drops to real low with the light coming on. replaced the pump which was a carter 170gph. put a new one on still same thing. pressurized the system holds air no leaks, pulled the top of cell to check the pickup no cracks. tore the pump back off checked the push rod this is what i found, the rod was tappered .020 from one side to the other and is .035 shorter than what is should be. ordering a new rod, pulling my hair out with this does this seem like it would be my problem. forgot to mention that at idle it works just fine it just under high rpms any help would be great , thank you

SBC? if so check the lobe on the cam, seen more then my share lately going flat on the fuel pump lobe.

[HuckleberryB4]

Had this issue before when the foam in the cell had broken down and it sucked up a piece in the pickup tube. It'd run fine at idle to 1/3 way down the chute, then it'd fall on it's face. At lower RPM's it could suck the fuel through/past the piece in the pickup. Then when it really started to pull fuel, it'd suck that piece almost solid.

[RSS]

One other thing to check is fuel cell vent, have seen this cause what you are explaining on 2 different cars, 1 actually semi collapsed the cell before they found it.

[cjsracing]

Everytime I replace the fuel pump I replace the rod. A while back we had this problem and I changed everything (fuel line, fuel pump) except the rod. Finally changed the rod and the issue disappeared. What I learned was that if the rod gets a little bit of wear it won't pump the pump properly at high rpms and will do what you are seeing.

[HuckleberryB4]

Anybody ever use one of the pump rods with the roller tip? Worth the $80?

[JustAddDirt]

Also make sure that the fuel filter is clean. I have seen new cells have a bunch of plastic drill shavings in them, they eventually get sucked up in the fuelfilter.
Also check to see if the pick up tube is in the bottom of the cell.
I have seen new ones that the hose was too long on and they curled up toward top of cell.(rubber hose)

[swingarm4life]

Make sure the filter is in correctly. Contrary to what some folks think, the car will idle fine with it in backwards depending on which side the spring is on.

[hupertracing24]

thanks everyone i bought a new rod going to try it will let u know if it fixes the problem