fuel psi dropping off on wot and mild accel help?????

G

Goss4675

New Member

Mar 17, 2010

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Feb 28, 2012

#1

• Feb 28, 2012

• #1

Hello everyone I have a 2003 gt 4.6 2v

My problem is fuel pressure drops a full throttle (wot and mild load between 2000-3000rpm)

Things I have done
Checked frpm power to unit battery voltage 12.8
Checked fuel pump For voltage ok

When condtion is present fuel presure gauge shows fuel psi drops off to
5psi engine sounds as if someone pulled the life out of it
but it does not stall

I gave the fuel pump a direct 12v with frpm unplugged
same condtion present
The fuel pump has been replaced
any one have any ideas ??????

 

G

Goss4675

New Member

Mar 17, 2010

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Feb 29, 2012

#2

• Feb 29, 2012

• #2

Goss4675 said:

Hello everyone I have a 2003 gt 4.6 2v

My problem is fuel pressure drops a full throttle (wot and mild load between 2000-3000rpm)

Things I have done
Checked frpm power to unit battery voltage 12.8
Checked fuel pump For voltage ok

When condtion is present fuel presure gauge shows fuel psi drops off to
5psi engine sounds as if someone pulled the life out of it
but it does not stall

I gave the fuel pump a direct 12v with frpm unplugged
same condtion present
The fuel pump has been replaced
any one have any ideas ??????

Click to expand...

 

Noobz347

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Feb 29, 2012

#3

• Feb 29, 2012

• #3

Fuel pump has been replaced with what?

 

trinity_gt

10 Year Member

Jan 31, 2003

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Feb 29, 2012

#4

• Feb 29, 2012

• #4

Check the fuel pressure sensor and vacuum line connection on the driver's side fuel rail.

When was the fuel filter last replaced?

When the pump was replaced (when and why?) was the pickup sock also replaced?

 

G

Goss4675

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Mar 17, 2010

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Feb 29, 2012

#5

• Feb 29, 2012

• #5

Noobz347 said:

Fuel pump has been replaced with what?

Click to expand...

with aaftermarket pump artex brand reused the old sender unit

 

Noobz347

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#6

• Feb 29, 2012

• #6

Goss4675 said:

with aaftermarket pump artex brand reused the old sender unit

Click to expand...

Please list your mods and the fuel pump rated output.

Also.. pull codes if you haven't already, to help rule out an electrical issue.

 

G

Goss4675

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Mar 17, 2010

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Feb 29, 2012

#7

• Feb 29, 2012

• #7

Airtex E2366 p/n spec

Maximum Free Flow Rate (gph): 75
Maximum Pressure Range (psi): 120
Minimum Free Flow Rate (gph): 65
Minimum Pressure Range (psi): 100
only mods to car
Professional Products Satin Typhoon Intake
magna flow mufflars

no codes in pcm
a friend of mines had a parts car these are the things we swapped out
fuel module
ccrm relay
MAF
Tps
fuel pressure sensor on rail

? I unplugged the fuel module in trunk and ran wires to the fuel pump directly at idle i was able to get 50psi but when I pressed on the throtle to 3/4 to full with pump connected to power i ran to it it still drops to 5-10psi and does not stall

Also if i push on the accelarator slowly The engine will rev up to the rev limiter
Thank You for your advise

both have been on car since i bought it. Id say alittle over a year

 

G

Goss4675

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Mar 17, 2010

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Feb 29, 2012

#8

• Feb 29, 2012

• #8

trinity_gt said:

Check the fuel pressure sensor and vacuum line connection on the driver's side fuel rail.

When was the fuel filter last replaced?

When the pump was replaced (when and why?) was the pickup sock also replaced?

Click to expand...

Thank you for your reply
The fuel filter and fuel pump were replaced at the same time at first when i saw fuel psi drop on data screen I thought the problem was just a bad pump

the vacuum line looks ok on the fuel rail. I swapped the fuel pressure sensor with a know good one but no success .

 

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor

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Jan 4, 1985

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Feb 29, 2012

#9

• Feb 29, 2012

• #9

Do you get a voltage drop at the pump when you see the pressure fall off?

 

H

Helbrass

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Oct 18, 2014

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Oct 18, 2014

#10

• Oct 18, 2014

• #10

My 2001 is doing the same thing. Did anyone make any progress on this?

 

Noobz347

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Oct 18, 2014

#11

• Oct 18, 2014

• #11

Goss4675 said:

Thank you for your reply
The fuel filter and fuel pump were replaced at the same time at first when i saw fuel psi drop on data screen I thought the problem was just a bad pump

the vacuum line looks ok on the fuel rail. I swapped the fuel pressure sensor with a know good one but no success .

Click to expand...

Ditch that Airtex and get a Walbro or something else. They are garbage, garbage, garbage.

Over the years I've ended up with three of their pumps for one reason or other. Each one that I've purchased new had to be replaced within a year. One of them was bad right out of the box and another lasted about a month.

I wouldn't even try to further troubleshoot with that pump installed because you can never trust it to NOT be the problem.

Edit:
One of those Airtex pumps would work flawlessly until it was heat soaked then freak out. I had great fun chasing my tail trying to find that problem.

 

Last edited: Oct 18, 2014

H

Helbrass

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Oct 18, 2014

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Oct 18, 2014

#12

• Oct 18, 2014

• #12

Turned out to be the Fuel Pump after all was said and done.