5.0gi TBI to Carb

[Galvez83]

Guys, after much headache and suffering with my TBI (a lot of money invested) still having issues. I have decided to go the route of Carb. What is needed to do a proper conversion using my current wiring harness. My current set up is a 2000 Volvo Penta 5.0GI PEFS TBI with serial # 4012007012, I know i will need

Carb
Spreadbore to squarebore adapter
Low psi fuel pump
Oil switch
Relay
Coil
Dizzi (read that stock Delco can stay)

The issue arrises when it comes to what wires go where to. Any thoughts?

 

[QBhoy]

Hi there. I can’t help you too much on this..but you mind if I ask what issues you had from the Tbi ? Never had one, but thought they were simple enough and reliable enough.

 

[alldodge]

If this was a Merc it would have 2 harnesses, motor and a EFI. There would be a connector which joins the 2 harnesses together. Does your motor have a similar connector?

 

[jimmbo]

If your engine has a 4bbl Intake, Volvo likely used one that accept Spreadbore Carbs as well as Squarebore
My fave carb for Marine engines up to and including 454s

Holley 0-80552 650 CFM Spreadbore Marine Carburetor

All Holley Marine Carburetors are designed to meet Coast Guard specifications. A marine carburetors fuel metering system is calibrated to compensate for unique engine loads found on boats. The J-style vent tubes direct fuel/fumes back into the carburetor for safe operation while on rough...

www.holley.com

However a 5 liter spinning 5200 rpm will find the 500cfm carbs perfectly sized

Marine Carburetors

All Holley Marine Carburetors are designed to meet Coast Guard specifications. A marine carburetors fuel metering system is calibrated to compensate for unique engine loads found on boats. The J-style vent tubes direct fuel/fumes back into the carburetor for safe operation while on rough waters.

www.holley.com

 

[Lou C]

I’m not sure about the wiring set up on the Volvo but I think if you can study the schematic you might be able to figure it out.
If someone has one to post up then we can make suggestions

 

[Scott Danforth]

You don't need an adapter

Just need to buy the right manifold.

Volvo runs a 500cfm Holley 2-barrel or a 650cfm Holley 4150 4-barrel

The manifold is very similar to the Edelbrock 2516

If your existing manifold has an adapter, just toss that and bolt on the carb.

Use a Holley fuel pressure regulator and you keep your existing fuel pump

 

[QBhoy]

You don't need an adapter

Just need to buy the right manifold.

Volvo runs a 500cfm Holley 2-barrel or a 650cfm Holley 4150 4-barrel

The manifold is very similar to the Edelbrock 2516

If your existing manifold has an adapter, just toss that and bolt on the carb.

Use a Holley fuel pressure regulator and you keep your existing fuel pump

Scott…sorry to hi jack a little..but have you known a holly to be fitted to a 5.7 repower engine, without an electric fuel pump before ? And tell me more about the holly fuel pressure regulator. What if there isn’t one of them fitted ? This is relating to a set of engines in a friends boat. Posted she’s ago about it. Thanks.

 

[alldodge]

Use a Holley fuel pressure regulator and you keep your existing fuel pump

Don't agree, the Gi has a low and high pump combined in one unit. Not going to regulate 55 psi down to 5 psi and keep it that way

 

[jimmbo]

You don't need an adapter

Just need to buy the right manifold.

Volvo runs a 500cfm Holley 2-barrel or a 650cfm Holley 4150 4-barrel

The manifold is very similar to the Edelbrock 2516

That Edelbrock looks very close, to the Intake that is on my VP5.7. It is a very well designed Intake. The runners look similar the runners on the 1970 LT1 Intake and can flow quite well

 

[jimmbo]

GDI
The link to the 2bbls used was FUBAR. so

Holley 0-82500 Holley Marine Avenger Carburetor

Building on the proven performance and durability of the Aluminum Street Avenger Series- we have engineered the new marine models to continue that performance heritage that Holley is known for. The all-aluminum carburetors are hard coat anodized in a Hard Core Gray finish to protect them from...

www.holley.com

Holley 0-80402-2 500 CFM Marine Carburetor-Aluminum

All Holley Marine Carburetors are designed to meet Coast Guard specifications. A marine carburetors fuel metering system is calibrated to compensate for unique engine loads found on boats. The J-style vent tubes direct fuel/fumes back into the carburetor for safe operation while on rough...

www.holley.com

Holley 0-80402-1 500 CFM Marine Carburetor

All Holley Marine Carburetors are designed to meet Coast Guard specifications. A marine carburetors fuel metering system is calibrated to compensate for unique engine loads found on boats. The J-style vent tubes direct fuel/fumes back into the carburetor for safe operation while on rough...

www.holley.com

Any of the above are pretty much the Perfect size for 5 liter spinning 5200

 

[Galvez83]

The engine has only one wiring harness that connects at the back of the boat. Regarding the carb i can work around that but my main concern would be the wiring to get everything going including gauges. I have read some people say its easy while others say they had to cut wires. This is my current set up.

 

[alldodge]

Your not helping
A wiring diagram from the manual doesn't necessarily show if there is or is not a connector. For the sake of discussion lets say there is not a connector. Follow the wires from the 10 pin which go to the ECM and the ones that do not.

The ones that do not, leave be, the ones that do identify and we can figure out where they need to go

 

[Galvez83]

Your not helping
A wiring diagram from the manual doesn't necessarily show if there is or is not a connector. For the sake of discussion lets say there is not a connector. Follow the wires from the 10 pin which go to the ECM and the ones that do not.

The ones that do not, leave be, the ones that do identify and we can figure out where they need to go

Tomorrow i will gut the harness open and take it from there.

 

[Scott Danforth]

That Edelbrock looks very close, to the Intake that is on my VP5.7. It is a very well designed Intake. The runners look similar the runners on the 1970 LT1 Intake and can flow quite well

both cast at Barr castings.

 

[Scott Danforth]

Don't agree, the Gi has a low and high pump combined in one unit. Not going to regulate 55 psi down to 5 psi and keep it that way

the OP has a TBI motor. either an 11 psi spring, a 15 psi spring or a 30 psi spring in the existing regulator assembly on the TBI assembly.

 

[alldodge]

Yes 30 psi not 55, The motor has a regulator in the TB, but the motor uses 2 fuel pumps mounted together and regulated to 29 psi +/- 2. Using a Holley Reg designed to regulate 10 psi or less down to 5, and have 30 coming in is not a good idea in my opinion

 

[Lou C]

Michigan Motorz sells the set up you’d need for a carb conversion (pump, bracket & oil pressure switch).
I’d want to see how the original ignition system is connected to the ECM and then figure out how to wire around that…might be able to eliminate the ECM entirely.

 

[Galvez83]

Update,
After a whole bunch of back and forth due to a bent crankshaft snout, crappy mechanics and machine shop, the engine is back. During the time that the engine was being repaired i changed to a 30lbs spring and changed the anti-siphon valve... still no improvement. The carb, equiptment are all on hold till i get a good mechanic to evaluate the current state of affairs of the boat.