4,3Gi different fuel pressure?

CFA

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A question from Sweden! Need to turn to the big guys (US) to get som real answers! :)

Why is it that 4,3Gi HU-BY operates on 11 psi but 4,3GiWT & 4,3GiEF operates on 29 psi? (read a n Pressure-matrix on this Forum)

I have a Volvo Penta 4,3GiPBYCCE which doen't get enough fuel? I have the 11 psi-pump...could it be that my enginge should have the 29 psi-pump?

(I have changed +1000 part on my enginge to make it run, not just the pumps, but it keeps dying when i give throttle?)
 
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nola mike

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4,3Gi HU-BY ... 4,3GiWT & 4,3GiEF ... 4,3GiPBYCCE
Welcome!
I don't know what any of those numbers are...
Maybe post a serial number or at least give us an idea of the year and what fuel system.
 

CFA

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Thanks, I”ll be more clear, sorry! They are the fuel pressure for the high pressure fuel pump. The codes are the official engine identification codes on this Vortec engine.

I have a 4,3Gi/-98, with code PBTCCE. I think the Gi was only produced 98-99 between the GL and GXi? Gi has the TBi-unit. But there seems to be different 4,3Gi…HU-BT, WT and EF? Why do these three have different HP-fuel pressure? 11 psi and 29 psi? (I neither talk about the GL nor the GXi)

Ser attatched?
Thanks again!
 
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Lou C

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I think you have a Volvo and you’re posting in the Mercruiser section they are like 2 different religions lol. Try posting this in the VP forum
 
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CFA

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I think you have a Volvo and you’re posting in the Mercruiser section they are like 2 different religions lol. Try posting this in the VP forum
Thanks, I saw that! It was moved by a Moderator! :)
 
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alldodge

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A question from Sweden! Need to turn to the big guys (US) to get som real answers! :)

Why is it that 4,3Gi HU-BY operates on 11 psi but 4,3GiWT & 4,3GiEF operates on 29 psi? (read a n Pressure-matrix on this Forum)

I have a Volvo Penta 4,3GiPBYCCE which doen't get enough fuel? I have the 11 psi-pump...could it be that my enginge should have the 29 psi-pump?

(I have changed +1000 part on my enginge to make it run, not just the pumps, but it keeps dying when i give throttle?)
Edit: scratch that the HU is at 11 psi

VP Fuel pressure.jpg
 

alldodge

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Guess to answer the question of why its only 11psi, is we would have to say is that's how it was designed. The injectors used in most cases as to what pressure limits.
 

CFA

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Guess to answer the question of why its only 11psi, is we would have to say is that's how it was designed. The injectors used in most cases as to what pressure limits.
Yes, but they are all Gi with the same power output? The reaaon for asking is that most shops just specify parts as ”Gi”, how do you know get the correct parts? Which parts can you mix etc?
 

Scott Danforth

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Yes, but they are all Gi with the same power output? The reaaon for asking is that most shops just specify parts as ”Gi”, how do you know get the correct parts? Which parts can you mix etc?
because you should be looking up parts by your serial number.

not the model number

each fuel system is different. the pumps are per the chart posted by AD
 

alldodge

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There should be different parts. If you go to volvopentashop.com and then select the serial number tab or engine and drive tab and enter info. Good thing is the new site work s much better then the old one

I just verified by selecting engine and drive tab, then started entering 4.3GiPBYCCE and selected it. The motor comes up for basics. Can then select Throttle body and the view shows up.

The issue is going to be the parts are no longer available. They are GM injectors and may be able to find them that way
 
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CFA

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because you should be looking up parts by your serial number.

not the model number

each fuel system is different. the pumps are per the chart posted by AD
That’s my point…but that has never been the case so far, the last 8-10 times I have bought parts!? I’m now courius to understand the difference between them?
 

CFA

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There should be different parts. If you go to volvopentashop.com and then select the serial number tab or engine and drive tab and enter info. Good thing is the new site work s much better then the old one

I just verified by selecting engine and drive tab, then started entering 4.3GiPBYCCE and selected it. The motor comes up for basics. Can then select Throttle body and the view shows up.

The issue is going to be the parts are no longer available. They are GM injectors and may be able to find them that way
Thanks! You are spot on…when I need to fine replacement part, or from Merc, almost all convertion only relates to ”Gi” only? => Always a gamble, that’s why I try to find out the difference to find the correct parts when serial number doesn’t go?
 

alldodge

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This probably won't help, but Merc 4.3 used 852956A1 injectors for all models but also was at 30 psi

And those cross reference to Mallory 9-33106 Standard TJ17 - Sierra 18-7685
 

alldodge

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(I have changed +1000 part on my enginge to make it run, not just the pumps, but it keeps dying when i give throttle?)

Just a thought
We really need more info on the issue. Things like does your fuel pressure stay at 11psi as the motor increases RPM thru to WOT?

If it does then its probably injectors, if it doesn't then it's in the fuel supply.

You could remove the TBI and change to a carb. Cheaper fix and then the 11 psi would need to be lower to below 8
 

Scott Danforth

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Volvo Penta Model numbers explained
4.3 = engine displacement
G = GM base motor (F = Ford Base Motor
L = Limited (4 barrel Carburetor) / I = Fuel Injection / S = 2 barrel carburetor / Si = High pressure fuel injection / Xi = MPI (Multi-Port Fuel injection)
P = Power Steering M=Manual Steering I = Inboard

Then you have the next two which is the year range. these are the most important numbers out of the alphabet soup.

the last number is generally a revision within the system

cut and pasted below from http://www.marineengine.com/boat-forum/showthread.php?395333-Vovlo-Penta-Gas-Engine-Identification



How do I identify my Volvo Penta gas engine and what does the model name tell me about the engine?

A metal tag is riveted to all Volvo Penta engines. Some of our products also have the information on a decal on the top of the product. Locate any of these on your engine and you will know the model. In the case above the name is 5.7Gi-B.

What does the model name tell me about my engine?

Several methods have been used to provide the engines with unique names. Some were based on horsepower ratings. More recent names are based on the displacement of the engine in liters.

Each time the name was changed, it was due to some change in the parts content of the engine. Sometimes the changes were minor, sometimes they were major. The changes may or may not affect the parts that you need for example a repair.

There are three distinct periods of gas engine production, each with a different naming method.

Red Engines, early


Very early engines, built until the late 1980.s, were named based on the displacement (early) or horsepower (later) of the engines. The name started with AQ (sterndrive engine), BB (inboard) or MB (inboard). Next came the number for the displacement or horsepower. Most of these also included a one letter suffix, for version control. An AQ271A is older (and different) than a AQ271B.
Examples: AQ260A, AQ171C, AQ200F, BB260A

These engine names then changed to a system based on displacement. The names were a three digit number, followed by a letter. The first two digits of the number represented the displacement. The 43 in 434A meant the engine was a 4.3L. The third digit was used for version control. A 430 and a 431 are both 4.3L.s, however the last digit indicates there is difference between the engines. The numbers at the third digit were not always sequential. 430.s were built before 431.s, however 432.s and 434.s were built at the same time.

The letter at the end was also used for version control and was sequential. A 500A was built before a 500B. These engines went out of production in 1993.
Examples: 432A, 500B, 251A, 740B

Nothing in the names in either of these systems relates in any way to years of production. Some of these engines were in production for less than a year, others for many years.

Charcoal engines

These engines were built during the joint venture with OMC and were painted a dark charcoal color. They were usually named by long character strings that contain two numbers followed by a series of letters.



  • The two numbers are the displacement.
  • Next is the letter that indicates who made the base engine. ( G=GM, F=Ford)
  • After that, one or two letters that note the fuel system and/or output. L=Limited, S=Superior, X=Exceptional, i or I=Fuel injected (no I means carburated).
  • Then one letter for the steering system. P=Power steering, M=Manual steering, X=Exact steering, I=Inboard
  • The next two letters are the most important for finding parts. These are random letter pairs that indicate the years of production for the engine. All parts information for these engines is based on these letter codes, including the charts that follow later in the book.



MD = 1993-1994 BY = 1997-1998
HU = 1994-1995 WT = 1998-1999
NC = 1995-1996 EF = 1999-2000
LK = 1996-1997

The next letter is also random and is used for version control. An .A. may not be the first version. .A.C. may not have been built before an .S.. An .S. in one engine's name may not mean the same thing as an .S. in another engine's name, especially if the engines have different displacements or production years. When needed this code is noted in the charts. There are instances where it is needed to find the right column for an engine.

Some names have the letters .CE. at the end. This indicates the engine meets certain emission requirements. The only service part affected is the ECU. These part numbers are noted when needed in the catalogs.

These engines went out of production in 2000.

Examples:

4.3GLPBYC = 4.3L, G=GM, L=limited output, carbureted (no i), P=power steering, BY=built 1997-1998, C=service code for version control.

5.8FSiPNCACE = 5.8L, Ford, Superior output, injected, power steering, NC=built 1995-1996, A service code, certified emissions.

7.4GLPHUS = 7.4L, GM, limited output, carbureted, power steering, HU=built 1994-1995, S service code.

3.0GLMMDA = 3.0L, GM, LIMITED output, carbureted, manual steering, MD=built 1993 1994, A service code.

Red Engines, current

Beginning in 2000 the gas engines are painted red again. The naming system was also changed. The first part of the name is the same as the charcoal engines, up to the letters for the fuel system.



  • The two numbers are the displacement.
  • Next is a letter that indicates who made the base engine. New engines have been added that use Volvo Penta's new Ocean Series sterndrives, these engines have an OS for this letter.
  • After that, one or two letters that note the fuel system and/or output.
  • For 3.0L only, there is an M or P for the steering
  • For Inboard engines only, there is an I after the lower case i.
  • Then a dash (-) followed by a one or two letter suffix. This is the major change from the charcoal engines above.
  • The first letter is the version control, this is present on all current engines. .A is the first version, -B is the second version, etc. There is no link between the suffix and production years. All engines with .A were not built the same year. A 5.7GXi-B and a 5.0GXi-B are not similar. A 4.3GL-D is newer than and different from a 4.3GL-C.
  • The second letter, if present is always an F, it notes that the engine is freshwater cooled.
    Examples: 3.0GLM-C, 4.3GXi-DF, 5.0OSi-E, 8.1GXiI-B


Now the difference in the fuel system.

carburetors are either 2 barrel or 4 barrel. Volvo likes to use Holley carbs
fuel injection is a mix of stock GM parts and volvo penta sourced parts

the 11 psi system is a stock GM Throttle Body (TBI) setup that had limited output

the 29psi system is a modified GM TBI unit with the fuel pump pressure turned up to get more output out of stock injectors.

the 50-60 psi is a 4 bar fuel pump in front of a 3-bar pile of GM and volvo sources components. again, the 60 psi is to get more power out of an injector that normally only has 43psi feeding it.

the only thing common between mercruiser and volvo is the base engine. that is the long block and the flywheel.

both at the time (prior from Mercruisers departure from GM) used the same industrial base engines. Volvo did specify different cams in some engines.

onto the fuel systems. each fuel system (Merc vs Volvo vs Ilmor vs Inmar) are developed in-house by each company.

they buy parts from the automotive world where they can. they have parts developed when they need to. Throttle bodies are GM, the IAC is GM on Volvo, and Ford for Mercruiser (because Mercruiser only had 2 pins left on their ECM for the IAC and the GM unit requires 4 pins vs the 2 pins for ford)

fuel pumps are carter for both Volvo Penta and Mercruiser
Throttle position switches are little river
Injectors are GM for Volvo and Magneti Marelli for Mercruiser
Regulators are GM for Mercuiser and i believe Bosch for Volvo.

Hope it helps
 

CFA

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Just a thought
We really need more info on the issue. Things like does your fuel pressure stay at 11psi as the motor increases RPM thru to WOT?

If it does then its probably injectors, if it doesn't then it's in the fuel supply.

You could remove the TBI and change to a carb. Cheaper fix and then the 11 psi would need to be lower to below 8
Thanks, I’m not hoping for support to fix my engine failiure in thread, unfortunately that’s another sisus.

I’m looking for answer why/what is the difference beteeen the different Gi abborre, which makes the fuel pressure differ? (FPR, injecots, High/Low fuel pump? Etc)

I got the answers in the thread.

Thanks again!
 

Scott Danforth

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Thanks, I’m not hoping for support to fix my engine failiure in thread, unfortunately that’s another sisus.
no reason not to tie it all in the same thread
 
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