????????????

I

i8av8

Donating Member
don't know how to describe my problem, but i'll try my hardest so that you guys might be able to help me out.
driving along and accelerating around 60-65 mph and it seems like power goes limp unless i keep accelerating, either hard or continuously past 65 mph and the fuel pressure goes to 43 lbs. the best way i can describe it is >it's like when driving a stick shift and you down shift into the wrong gear and you stay in that gear until you get back up to speed. (if that description even helps?)
normal driving i've got 38-39 lbs. fuel pressure. if i accelerate hard then it goes to 40-43 lbs. fuel pressure.
~afpr "T"d into map vacuum line
~no cat. converter
~no knock
~no check engine light
~running at 18 lbs. of boost (only in WOT)
~only use chevron 93
just listing things that might help you guys to figure stuff out
 
Don W.

Don W.

Stab it and steer it
Re: ????????????

Subject to correction here by others but it sounds like you're going lean. 40-43lbs FP ain't enough for 18lbs of boost. Should be 60+/- :2cents:
 
I

i8av8

Donating Member
Re: ????????????

Don W. said:
Subject to correction here by others but it sounds like you're going lean. 40-43lbs FP ain't enough for 18lbs of boost. Should be 60+/- :2cents:
Click to expand...

MAKES SENSE
to cure it? do i need to adjust the afpr if in-fact that is the problem?

..or i guess i could just dial down the boost, huh? seems like an easier fix. i just set it to 18 lbs. just to see what the ty could do. threw me in the seat rather well from a 20, 30, 40, 50 ect. roll. just d!@*ing around!
 
S

SCWolverine

New member
Re: ????????????

You don't adjust the "rise-rate" on the fpr, just the "base" FP. You should see +1 psi fuel for every +1 psi boost (38-39 + 18 = 56-57 @ wot).

Get a WBO2 on it and see what your AFRs are doing when you experience what you're describing.

Check/recheck/re-recheck all vacuum lines common to the AFPR.

Sanity-check your FP (mechanical gauge on the rail).

Keep us posted of your findings...
Best of luck!
 
I

i8av8

Donating Member
Re: ????????????

SCWolverine said:
You don't adjust the "rise-rate" on the fpr, just the "base" FP. You should see +1 psi fuel for every +1 psi boost (38-39 + 18 = 56-57 @ wot).

Get a WBO2 on it and see what your AFRs are doing when you experience what you're describing.

Check/recheck/re-recheck all vacuum lines common to the AFPR.

Sanity-check your FP (mechanical gauge on the rail).

Keep us posted of your findings...
Best of luck!
Click to expand...

sorry, kinda lost with what you're saying there.
new o2 sensor, but i just asked for a stock replacement. is stock not WB? could that be a problem? do you have a part # in anything other than bosch?
 
S

SCWolverine

New member
Re: ????????????

No, stocker isn't WB, it's an upgraded (deemed by most to be a necessity before serious tuning). A WB patched in to the ecm will let you see exactly what your AFR is doing when you have the funky issues you described (it can be logged by Datamaster or Tunerpro alongside your other data). Running 18psi on 93 octane with only 40-43 psi of fuel and no knock just doesn't sound right (more power to you if this is the case!) Getting some true AFR readings should clear some things up [/broken record].
 
I

i8av8

Donating Member
Re: ????????????

with the headache that i have from this, i seem to have forgotten that i have a street/strip box in my glove-box set to first setting which is ~15 psi street. don't know the brand, but it takes a key to lock/unlock it when i want to change settings. i'll try it on 18 psi. and see how that goes and report back.
 
gkrcr882

gkrcr882

SyTyless......for now!
Re: ????????????

i8av8 said:
with the headache that i have from this, i seem to have forgotten that i have a street/strip box in my glove-box set to first setting which is ~15 psi street. don't know the brand, but it takes a key to lock/unlock it when i want to change settings. i'll try it on 18 psi. and see how that goes and report back.
Click to expand...



Put the key down!! Worst thing you can do for a poorly running truck is throw more boost at it, especially if its a suspected lean condition.
 
I

i8av8

Donating Member
Re: ????????????

gkrcr882 said:
Put the key down!! Worst thing you can do for a poorly running truck is throw more boost at it, especially if its a suspected lean condition.
Click to expand...

no problems until i set it to 18 psi. from previous 11 psi.
 
S

SCWolverine

New member
Re: ????????????

Have you seen the new sensor knock? If not I'd check your knock sensor (hammer-test) to be sure it's alive. Consider getting set up to at least log, preferably with a WB incorporated. From that point it's not much farther to go to be able to do your own tuning...
I'd stay the hell away from the 18psi setting until you're sure about everything else.
 
I

i8av8

Donating Member
Re: ????????????

SCWolverine said:
Have you seen the new sensor knock? If not I'd check your knock sensor (hammer-test) to be sure it's alive. Consider getting set up to at least log, preferably with a WB incorporated. From that point it's not much farther to go to be able to do your own tuning...
I'd stay the hell away from the 18psi setting until you're sure about everything else.
Click to expand...

every time i start the truck the knock sensor/l.e.d. beeps/flashes. only once, though.
as far as that data master goes, that is all giberish to. not to mention i don't know anyone around me with one. i guess i am just up $#!t creek. the best thing i can do is just dial it back down to 11ish psi. which i already did. even on my snap-on scanner i get nothing. all checks out.

note: near wot i do get up to 45-50 psi. on fuel pressure. sorry, that was my mistake.
 
I

i8av8

Donating Member
Re: ????????????

update: adjusted the throttle linkage, tv cable and gas pedal. i now have 100% throttle. i was only getting about 80%. can feel a huge difference ! more responsive.
 
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