adjustable fuel pressure regulator
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Joined: Nov 2009
Posts: 30
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From: St louis mo
Car: 1991 z28 Convertable
Engine: Tpi 350
Transmission: 700r4
Axle/Gears: 273 built ten bolt posi
adjustable fuel pressure regulator
i have a adjustable fpr bought used screw is pretty far out i need to know where to have it at i wat it at a step or two above stock for a 5.7 also i have a modified fuel rail with a pressure gauge if that helps on the tuning thanks in advance.
Joined: Apr 2005
Posts: 7,736
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From: Not in Kansas anymore
Car: 82 Z28
Engine: 383 SP EFI/ 4150 TB
Transmission: T400
Axle/Gears: QP 9" 3.73
Re: adjustable fuel pressure regulator
A fullstop every now and then would make your posts MUCH easier to read
You need stock pressure setting ( 43 -45 psi ) with vac line disconnected and bigger (350 ) injectors
Last edited by vetteoz; Dec 25, 2010 at 01:39 AM.
Supreme Member
Joined: Nov 2003
Posts: 1,629
Likes: 17
From: Somewhere
Car: 88 IROC
Engine: 305 TPI
Transmission: 700R4
Axle/Gears: 10 bolt 3.73
Re: adjustable fuel pressure regulator
Tech questions are not going to work in that format. A little to much texting for this guy. Thread Starter
Junior Member
Joined: Nov 2009
Posts: 30
Likes: 0
From: St louis mo
Car: 1991 z28 Convertable
Engine: Tpi 350
Transmission: 700r4
Axle/Gears: 273 built ten bolt posi
Re: adjustable fuel pressure regulator
yea i do text a lot but i definetly dont spend my life in a forum,needed some advice on my car thats all school taught me well,but with that being said you still didnt answer the question cause i asked for the setting above stock.
Joined: Apr 2005
Posts: 7,736
Likes: 14
From: Not in Kansas anymore
Car: 82 Z28
Engine: 383 SP EFI/ 4150 TB
Transmission: T400
Axle/Gears: QP 9" 3.73
Re: adjustable fuel pressure regulator
Read bottom of my post above 
You need stock pressure setting ( 43 -45 psi ) with vac line disconnected
Your original info / question is very vague.
From your other post about having a flat tappet '89 350 to replace your 305; it looks like you are trying to run a 350 on a 305 tune with 305 injectors by turning up the fuel pressure .You make no mention of having 350 injectors or a 350 chip
You can't run a 350 in your 305 car by just turning up the fuel pressure

You need stock pressure setting ( 43 -45 psi ) with vac line disconnected
Your original info / question is very vague.
From your other post about having a flat tappet '89 350 to replace your 305; it looks like you are trying to run a 350 on a 305 tune with 305 injectors by turning up the fuel pressure .You make no mention of having 350 injectors or a 350 chip
You can't run a 350 in your 305 car by just turning up the fuel pressure
Last edited by vetteoz; Dec 25, 2010 at 05:42 PM.
Thread Starter
Junior Member
Joined: Nov 2009
Posts: 30
Likes: 0
From: St louis mo
Car: 1991 z28 Convertable
Engine: Tpi 350
Transmission: 700r4
Axle/Gears: 273 built ten bolt posi
Re: adjustable fuel pressure regulator
trust me i have everthing i need chip,under drive pulleys ect some injectors are just out of the question for two pounds less wont make a difference for 600 bucks thats with my discount at advance so i guess im just cheap then.
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Supreme Member
Joined: Apr 2010
Posts: 4,337
Likes: 29
From: Aurora, OR
Car: 87 IROC Z28
Engine: 355 cid TPI
Transmission: Custom Built 700R4 w/3,500 stall
Axle/Gears: QP fab 9" 3.70 Truetrac
Re: adjustable fuel pressure regulator
Lb/hr rating is based on 40psi(bosch). Increasing pressure increases output on a linear scale. Therefore, increasing pressure 25%(10psi) will increase injector output 25%(4.75lbs). as far as what works for your engine combo, that you have to figure out for yourself. I would suggest using a wideband O2 AFR meter to check your settings.
Also, running stock, and I assume original injectors in your "stage 3" 350, (what stage 3 means I couldn't begin to guess) is a bad idea. Look at Southbay Injectors for a price on some 22lb/hr Bosch IIIs. Prob about $200
Also, running stock, and I assume original injectors in your "stage 3" 350, (what stage 3 means I couldn't begin to guess) is a bad idea. Look at Southbay Injectors for a price on some 22lb/hr Bosch IIIs. Prob about $200
Joined: Apr 2005
Posts: 7,736
Likes: 14
From: Not in Kansas anymore
Car: 82 Z28
Engine: 383 SP EFI/ 4150 TB
Transmission: T400
Axle/Gears: QP 9" 3.73
Re: adjustable fuel pressure regulator
Thread Starter
Junior Member
Joined: Nov 2009
Posts: 30
Likes: 0
From: St louis mo
Car: 1991 z28 Convertable
Engine: Tpi 350
Transmission: 700r4
Axle/Gears: 273 built ten bolt posi
Re: adjustable fuel pressure regulator
incorrect the bosch ones are $98 dollars a peice,and stage 3 was me referring to the prom chip im running
Thread Starter
Junior Member
Joined: Nov 2009
Posts: 30
Likes: 0
From: St louis mo
Car: 1991 z28 Convertable
Engine: Tpi 350
Transmission: 700r4
Axle/Gears: 273 built ten bolt posi
Re: adjustable fuel pressure regulator
@vetteoz thanks for the spell check Mr.perfect,but just putting some RANDOM injectors in is out of the question the stock ones were working correctly if you know anything about cars then you should know they have to have the same ohms....now txt that.
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Joined: Oct 2008
Posts: 222
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Car: 1985 Camaro Iroc-Z
Engine: LB9
Transmission: 700R4
Axle/Gears: 3.42
Re: adjustable fuel pressure regulator
Bosch III's can indeed be had for less than $600 for a set o.O
2 different companys who sell them have already been mentioned and probably more than 30% of this forum are running injectors from them, So. Nobody is trying to trick you man lol
You've already been told the stock pressure it needs, Why you need a afpr for a stock 350 is beyond me (if it is stock, not much info in this thread), And if 19lb injectors would work on 350's just fine, i dont see why chevrolet even put bigger in the 350's. They're such idiots lol
2 different companys who sell them have already been mentioned and probably more than 30% of this forum are running injectors from them, So. Nobody is trying to trick you man lol
You've already been told the stock pressure it needs, Why you need a afpr for a stock 350 is beyond me (if it is stock, not much info in this thread), And if 19lb injectors would work on 350's just fine, i dont see why chevrolet even put bigger in the 350's. They're such idiots lol
Joined: Apr 2005
Posts: 7,736
Likes: 14
From: Not in Kansas anymore
Car: 82 Z28
Engine: 383 SP EFI/ 4150 TB
Transmission: T400
Axle/Gears: QP 9" 3.73
Re: adjustable fuel pressure regulator
If you know anything about cars .
Everybody ( except you ) is running the latest design in injectors, not something with 25 year old technology like the OEM Bosch injectors
Nothing random about these
http://fuelinjectorconnection.com/sh...&productId=134
Do a search on 3rd Gen and see what guys say after they have fitted them
Also available from Southbay and Injectors Plus
If you were up with the game plan you would know nobody pays that price
LOL ,
Go over to the 3rd Gen tuning dept and ask what a "stage 3 " chip is
What size injectors is your " stage 3" chip tuned for?
Everybody ( except you ) is running the latest design in injectors, not something with 25 year old technology like the OEM Bosch injectors
Nothing random about these
http://fuelinjectorconnection.com/sh...&productId=134
Do a search on 3rd Gen and see what guys say after they have fitted them
Also available from Southbay and Injectors Plus
If you were up with the game plan you would know nobody pays that price
LOL ,
Go over to the 3rd Gen tuning dept and ask what a "stage 3 " chip is
What size injectors is your " stage 3" chip tuned for?
Last edited by vetteoz; Jan 23, 2011 at 11:53 PM.
Re: adjustable fuel pressure regulator
This is hard to follow.
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From: Pleasant Grove, Utah
Car: 1993 GMC Typhoon
Engine: 4.3 Turbo
Transmission: 4L60
Axle/Gears: 3.42
Re: adjustable fuel pressure regulator
my head hurts from reading this... can some translate this bull crap?
Supreme Member
Joined: Nov 2003
Posts: 1,629
Likes: 17
From: Somewhere
Car: 88 IROC
Engine: 305 TPI
Transmission: 700R4
Axle/Gears: 10 bolt 3.73
Re: adjustable fuel pressure regulator
The guy just wants to know what to set his fuel pressure at for additional performance. I usually set at 46 to 48psi and yield good results. At around 50 PSI I found the injectors will tend to be a bit noisey and the idle quality will start to suffer.
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Posts: 744
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From: sf bayarea
Car: 91 z28
Engine: 350/ported accel tpi/AFR 195
Transmission: t-5 =(
Axle/Gears: 345
Re: adjustable fuel pressure regulator
Im a little confused your asking for help and you insult someone with alot of insight on these cars. Being polite goes along way and you will get alot more help on here
Joined: Apr 2005
Posts: 7,736
Likes: 14
From: Not in Kansas anymore
Car: 82 Z28
Engine: 383 SP EFI/ 4150 TB
Transmission: T400
Axle/Gears: QP 9" 3.73
Re: adjustable fuel pressure regulator
Simple
The crux of the problem is he wants to run his 19lb 305 injectors in his new 350 ( "two pounds less wont make a difference" ) by just turning up the fuel pressure
When told he needs 350 injectors for it to run right, his comeback is can't afford new injectors
"bosch ones are $98 dollars a peice,"
The crux of the problem is he wants to run his 19lb 305 injectors in his new 350 ( "two pounds less wont make a difference" ) by just turning up the fuel pressure
When told he needs 350 injectors for it to run right, his comeback is can't afford new injectors
"bosch ones are $98 dollars a peice,"
Last edited by vetteoz; Jan 25, 2011 at 01:50 AM.
Re: adjustable fuel pressure regulator
Simple
The crux of the problem is he wants to run his 19lb 305 injectors in his new 350 ( "two pounds less wont make a difference" ) by just turning up the fuel pressure
When told he needs 350 injectors for it to run right, his comeback is can't afford new injectors
"bosch ones are $98 dollars a peice,"
The crux of the problem is he wants to run his 19lb 305 injectors in his new 350 ( "two pounds less wont make a difference" ) by just turning up the fuel pressure
When told he needs 350 injectors for it to run right, his comeback is can't afford new injectors
"bosch ones are $98 dollars a peice,"
Thread Starter
Junior Member
Joined: Nov 2009
Posts: 30
Likes: 0
From: St louis mo
Car: 1991 z28 Convertable
Engine: Tpi 350
Transmission: 700r4
Axle/Gears: 273 built ten bolt posi
Re: adjustable fuel pressure regulator
everybody always has somthing smart to say so which one of you guys car is actually worth any money??? just asking
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Posts: 744
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From: sf bayarea
Car: 91 z28
Engine: 350/ported accel tpi/AFR 195
Transmission: t-5 =(
Axle/Gears: 345
Re: adjustable fuel pressure regulator
Well we all dont have stage 3 irocs so im not sure they are worth as much as yours.
Im sure alot of us have alot of time and money in our cars so to each their own ...
Im sure alot of us have alot of time and money in our cars so to each their own ...
Thread Starter
Junior Member
Joined: Nov 2009
Posts: 30
Likes: 0
From: St louis mo
Car: 1991 z28 Convertable
Engine: Tpi 350
Transmission: 700r4
Axle/Gears: 273 built ten bolt posi
Re: adjustable fuel pressure regulator
your running a little late thats actually my last years car this wat im putting together now
Last edited by IROC_Champion; Feb 4, 2011 at 12:17 AM. Reason: typo
Senior Member
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Joined: Aug 2007
Posts: 744
Likes: 1
From: sf bayarea
Car: 91 z28
Engine: 350/ported accel tpi/AFR 195
Transmission: t-5 =(
Axle/Gears: 345
Re: adjustable fuel pressure regulator
what is a stage 3 iroc if you dont mind me asking im kind of intrigued
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Joined: Feb 2005
Posts: 2,642
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From: Pleasant Grove, Utah
Car: 1993 GMC Typhoon
Engine: 4.3 Turbo
Transmission: 4L60
Axle/Gears: 3.42
Re: adjustable fuel pressure regulator
Stage 7 B4C/1LE super vector cross ram TPI here.. thats WITH dual muffler bearings and triple action force fed charge air cooler... $41k invested...
Thread Starter
Junior Member
Joined: Nov 2009
Posts: 30
Likes: 0
From: St louis mo
Car: 1991 z28 Convertable
Engine: Tpi 350
Transmission: 700r4
Axle/Gears: 273 built ten bolt posi
Re: adjustable fuel pressure regulator
you need to do some research http://www.iroc-z.com they have everthing you need to know producton numbers option codes.....just read a little please
Thread Starter
Junior Member
Joined: Nov 2009
Posts: 30
Likes: 0
From: St louis mo
Car: 1991 z28 Convertable
Engine: Tpi 350
Transmission: 700r4
Axle/Gears: 273 built ten bolt posi
Re: adjustable fuel pressure regulator
i just bought this one only had it for three months versus you who probly had your's for several years think about it
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Joined: Jul 2010
Posts: 189
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From: ATX
Car: Trans am
Engine: 78 350
Transmission: T56
Axle/Gears: 9 bolt 3.27
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