96 cobra breaks up under WOT

Rons95GT

Not a new member
Joined
Aug 4, 2020
Messages
76
Reaction score
49
10 months. I filled it with fresh gas and stabilizer just before I left.
 

Adultingsucks

New Member
Joined
Jan 26, 2022
Messages
8
Reaction score
3
Just a follow-up. Pulled an amp reading of the fuel pump feed at idle. Current draw is 6.4a @ idle. Won't be able to do a WOT amp measure until the snow clears.
 
OP
OP
P

Pedrothecobra

Member
Joined
Dec 22, 2021
Messages
101
Reaction score
16
yea the snow kinda put a wrench in my plans. i have to get another car done before i can get back on it
 

95opal

Well-Known Member
Joined
Jun 21, 2007
Messages
3,015
Reaction score
1,582
One issue that i know that plagues are fuel tanks is the fuel return causing cavitation with in the fuel box(i cant remember the proper term for it). This is the box surrounding the pump to stablize fuel waving in the tank. Fuel thats returned to the tank needs a line that directs the fuel away from the pumps location because the returning fuel splashes around the pump creating cavitation. Your situation could be as simple as this but requires dropping the tank to check it. The return hose inside the tank is known for this problem. Simply redirection the hose. Sometimes the hose comes off and will most definitely blast the stable fuel supply for the pump.

I nominate dropping the tank
Aeration
 

Makoto

Active Member
Joined
Nov 24, 2016
Messages
839
Reaction score
745
Location
Houston
here's what I would do. bypass everything in the fuel pump circuit (and there is a lot) by powering the fuel pump itself with the proper voltage. its return style so it'll just send excess fuel back to the tank. basically, hotwire that thing and if it still happens you know to stop looking at the fuel pump circuit. Or maybe if you jump it and only get like 20psi you can know you probably have a weak pump or fpr.
 

lwarrior1016

Mr. Secondary Timing Chain
Staff
Joined
Sep 22, 2014
Messages
8,535
Reaction score
4,330
Location
South Mississippi
Just sit down. Your clueless ‍♂️

Thanks you dick sucking Rocket Scientist
Alright fellas, there’s no need for personal attacks. We don’t need attitudes or comments like this. Everyone is just trying to help, insults aren’t helpful. Please dial it back.
 
OP
OP
P

Pedrothecobra

Member
Joined
Dec 22, 2021
Messages
101
Reaction score
16
so i finally got the tank dropped and the pump out. i didnt see any line on the return side of the pump inside the tank, this pump is only 2 months old and has that little valve clamped onto the return. going off the numbers on this pump its only 90lph, the only hose i see is the line coming off the top of the pump(which looks good) that feeds.

i am curious what that tube with the nipple sticking up inside the tank is for and if there is supposed to be a hose on the end of the return and not the red valve. i bypassed the relay and have 13v constant to my pump and im still dropping pressure in the higher RPM range mainly over 4k when im laying into it.

i will be blowing out the fuel lines tonight just for peace of mind, im starting to wonder if maybe this pump just cant keep up with the demand? i have the tank out already i may just put a bigger pump in while its out. but i want to try and isolate this pressure drop and the cause before i just throw more money at this thing. any insite would be greatly appreciated
 

Attachments

  • 66606312722__576DEB0D-94AC-4181-882B-5CAD3365C800.jpg
    66606312722__576DEB0D-94AC-4181-882B-5CAD3365C800.jpg
    179.5 KB · Views: 8
  • 66606321625__9C83CC55-0A69-48E7-87B9-AE1B48655324.jpg
    66606321625__9C83CC55-0A69-48E7-87B9-AE1B48655324.jpg
    131.7 KB · Views: 8
  • IMG_1983.jpg
    IMG_1983.jpg
    212.5 KB · Views: 8
  • IMG_1984.jpg
    IMG_1984.jpg
    226 KB · Views: 8
  • IMG_1985.jpg
    IMG_1985.jpg
    208.8 KB · Views: 8

ttocs

Post Whore
Joined
Oct 9, 2009
Messages
32,614
Reaction score
5,652
Location
Evansville Indiana
the fuel sock looks a little dirtier than I have seen mine be. Its possible that a little pump with a slight restriction just was not able to keep up with the flow needed at higher rpms even though it kept the psi up.
 
OP
OP
P

Pedrothecobra

Member
Joined
Dec 22, 2021
Messages
101
Reaction score
16
the fuel sock looks a little dirtier than I have seen mine be. Its possible that a little pump with a slight restriction just was not able to keep up with the flow needed at higher rpms even though it kept the psi up.
the PSI drops to about 20. i was thinking the sock looked a bit dirty but ive seen worse, do you know what that pipe with the nipple in the tank is for?
 
OP
OP
P

Pedrothecobra

Member
Joined
Dec 22, 2021
Messages
101
Reaction score
16
pretty sure that is the fuel return but I would wait for someone else to confirm
yea im curious if that just to keep a certain level in that pan for the pump. looking at other pics of new pumps they all have that red valve clamped onto the return
 

Adultingsucks

New Member
Joined
Jan 26, 2022
Messages
8
Reaction score
3
Going by the Delphi number, here are the specs;
Outlet Size-3/8 in
Amp Draw-7
Flow Rate-29 gal/hr
Inlet Type-Strainer
Pump Type-Turbine
Relief Pressure-80-123 psi
Strainer Location-External
System Pressure-36 psi
Volts-12 vDC
Manufacturer's Part Number:-HP10145

29 gal/h should equate to 109.777 lt/h.
I think its either it's undersized or your tank's fuel level was too low, under a 1/4, to be going WOT.
 
OP
OP
P

Pedrothecobra

Member
Joined
Dec 22, 2021
Messages
101
Reaction score
16
Going by the Delphi number, here are the specs;
Outlet Size-3/8 in
Amp Draw-7
Flow Rate-29 gal/hr
Inlet Type-Strainer
Pump Type-Turbine
Relief Pressure-80-123 psi
Strainer Location-External
System Pressure-36 psi
Volts-12 vDC
Manufacturer's Part Number:-HP10145

29 gal/h should equate to 109.777 lt/h.
I think its either it's undersized or your tank's fuel level was too low, under a 1/4, to be going WOT.
Yea I was thinking that the level could be an issue. But now the pump is out I kinda want to put something better in there so I don’t have to do it later
 

ttocs

Post Whore
Joined
Oct 9, 2009
Messages
32,614
Reaction score
5,652
Location
Evansville Indiana
I would not go through all that and put the stock pump back in myself. Aeromotive makes some that fit and will give you room to grow.
 

Forum statistics

Threads
77,492
Messages
1,503,713
Members
14,964
Latest member
bs.austin.tx

Members online

Top