your thoughts please

BlackVert

15 Year Member

Oct 3, 2003

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Bethesda, MD

Oct 26, 2004

#1

• Oct 26, 2004

• #1

i recently installed a used stock fuel pressure regulator. i have the stock maf back in. and i have stock injectors.

i set my high and low slopes back to stock (28.8/19.64). the kamrfs were around 1.15. i have lowered them both gradually. the high slope is now 17, low is 26. it is still lean, but not as lean.

i am thinking it must be one of:

(1) fpr is bad
(2) fpr was dirty or rusty, injectors and/or fuel filter are now clogged
(3) vacuum tube from intake to fpr is not very tight, not enough vacuum

any other thoughts?

 

BlackVert

15 Year Member

Oct 3, 2003

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#2

• Oct 26, 2004

• #2

ttt

 

mytight95

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Dothan,Al

Oct 26, 2004

#3

• Oct 26, 2004

• #3

the reg is good........i assume you changed the values with the tweecer or something.........

.........

only thing i can think of is if the car has mods.......you may need more pressure....PUMP.........or that the filter is clogged.......pump could be going bad....................hey man e-mail me what it is doing....mytight95@msn.com..........are you checking the pressure with the vacuum off..............


jason

 

BlackVert

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Oct 26, 2004

#4

• Oct 26, 2004

• #4

mytight95 said:

the reg is good........i assume you changed the values with the tweecer or something.........

.........

only thing i can think of is if the car has mods.......you may need more pressure....PUMP.........or that the filter is clogged.......pump could be going bad....................hey man e-mail me what it is doing....mytight95@msn.com..........are you checking the pressure with the vacuum off..............

jason

Click to expand...

ever run out of gas? it acts like it is on the verge of running out of gas.
it was much worse on the way home.

- i believe that the fpr is not bad
- yes i changed the values with my tweecer.
- my mods are not nearly extensive enough that there is no possible way i am maxxing out the injectors. the highest duty cycle i have seen is like 15%.
- could be the pump - good point
- i need to dig up my fuel pressure gauge and hook it up.

 

mytight95

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Dothan,Al

Oct 26, 2004

#5

• Oct 26, 2004

• #5

yeah i would do that.............with the gauge............i would guess that the pump is going bad or the filter is clogged if you are only seeing 15% duty cycle...................


you need to check the pressure.......check the filter etc. i think.................try and run it without vacuum on the reg.........block off the vacuum line from the intake.......drive it.........see how it does..............





jason

 

BlackVert

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Oct 3, 2003

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Oct 26, 2004

#6

• Oct 26, 2004

• #6

stupid question time: will taking the vac line off increase the pressure or decrease it?

 

BlackVert

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Oct 26, 2004

#7

• Oct 26, 2004

• #7

Black96VertGT said:

stupid question time: will taking the vac line off increase the pressure or decrease it?

Click to expand...

ok, i got the answer to this one: the pressure will go up.

another question: after replacing the fpr, do you need to do anything to get the air out of the fuel lines?

 

HISSIN50

"How long does it take to get help in here?

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Nov 29, 1999

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Oct 27, 2004

#8

• Oct 27, 2004

• #8

Black96VertGT said:

another question: after replacing the fpr, do you need to do anything to get the air out of the fuel lines?

Click to expand...

prime the pump.

the system flows enough pressure to purge the system of air (unlike old low pressure mech pumps).

good luck.