L31 into an '86 Regal Limited V8

[Doober]

Direct replacement=it will go directly in place of the TBI pump. If you try to buy a pump from a 2002 Silverado it just plain won't work. A TBI pump can't support a stock Vortec engine, period. It doesn't have the volume, nor the pressure capacity. If you try to use a TBI pump on a Vortec engine you will see poor results.

 

[L92 OLDS]

A TBI pump can't support a stock Vortec engine, period. It doesn't have the volume, nor the pressure capacity

The pressure ratings are obviously different between TBI and EFI but are you sure the volume isn't adequate? Some guys use a TBI pumps with carbed big blocks.

 

[DRIVEN]

Vortec fuel system is very pressure sensitive. The spec is 61-66psi and I've seen them NOT even run at 55psi. If you aren't familiar with Vortec's spider system, it's worth reading up on it. Some of the replacement spiders were revised to move the electrical portion out to where the poppet valves were which makes them much more forgiving. The original Vortec design was great on paper and worked well as long as every component was healthy. Not so much when the poppets got dirty and the fuel pump gets tired.

 

[ATL Regal]

'96-'97 pumps are a direct replacement for the TBI pump, I replaced the pump in my '92 (originally 4.3 v6).

If you are going carbed, you can simply run any regular SBC G-Body headers.

The hump on the crossmember does go on the passenger side, you'll find this out when you get the crossmember under the car and try to bolt it up.

Direct replacement=it will go directly in place of the TBI pump. If you try to buy a pump from a 2002 Silverado it just plain won't work. A TBI pump can't support a stock Vortec engine, period. It doesn't have the volume, nor the pressure capacity. If you try to use a TBI pump on a Vortec engine you will see poor results.

But how does any kind of TBI pump apply to this application??
I'm going from a carbed Olds 307 to an EFI L31.

Unless you're saying that I can get a TBI sending unit that fits my tank and replace the pump on it with a pump that supports the L31's needs?


Sent from my DROID BIONIC using Tapatalk 2

 

[ATL Regal]

Vortec fuel system is very pressure sensitive. The spec is 61-66psi and I've seen them NOT even run at 55psi. If you aren't familiar with Vortec's spider system, it's worth reading up on it. Some of the replacement spiders were revised to move the electrical portion out to where the poppet valves were which makes them much more forgiving. The original Vortec design was great on paper and worked well as long as every component was healthy. Not so much when the poppets got dirty and the fuel pump gets tired.

Please forgive my ignorance..
So I can't just overcompensate and get a 80 or 90 psi pump because it'll be too much pressure?

Also, what is a spider system, and a poppet?

Sent from my DROID BIONIC using Tapatalk 2

 

[DRIVEN]

You can get away with a higher pressure than the 61-66psi spec because the pressure regulator will return excess pressure to the tank. You just can't use a lower pressure pump because you need a minimum pressure to overcome the poppet spring pressure.
You really should take some time to familiarize yourself with how the Vortec CPI works. It's not a traditional EFI system but can be retrofitted. This link has some pics and a brief description of the differences. http://www.fuelinjector.citymaker.com/V ... rsion.html
Once you understand the way it works you'll be able to properly design the fuel system and then better diagnose any problems that may pop up in the future.

 

[Doober]

You are correct by inferring I meant use a stock G-Body TBI sending unit to hang a Vortec pump. That way it's a drop-in deal, no special work is required outside a typical fuel pump change. A fuel pump has to supply the volume along with the pressure, which is why a TBI pump could supply a carbed BBC (low pressure), but not a high pressure Vortec setup. Pumps also have a volume limit though, so a case such as the TBI pump being able to supply a carbed BBC may not always apply.

Read this for some more info on fuel delivery capacity vs. horsepower.
http://aeromotiveinc.com/2010/01/fuel-p ... orsepower/

To alleviate tl;dr syndrome, I'll quote what I'm getting at:

To illustrate this, take one of the most popular and efficient EFI pumps on the market, Aeromotive’ A-1000 part #11101. Lets examine various pressures to demonstrate the effect this has on flow volume:
· Carbureted, Nat Aspirated, 9psi and 13.5v, volume 791lbs/hr. 1,582 HP @ .5 BSFC.
· EFI, Nat. Aspirated 43.5psi and 13.5v, volume 614lbs/hr. 1,228 HP @ .5 BSFC.
· 20psi boost/1:1 Regulator, intercooler, 60psi and 13.5v, volume 529lbs/hr. 881 HP @ .6 BSFC
· 10psi boost/4:1 FMU, intercooler, 80psi and 13.5v, volume 426lbs/hr. 710 HP @ .6 BSFC
· 6psi boost/8:1 FMU, intercooler, 91psi and 13.5v, volume 370lbs/hr. 616 HP @ .6 BSFC

Basically the more pressure a pump has to apply, the lower the volume.

Also, even though I've never really looked into it, it's possible a TBI pump may build up the required pressure, it would be way short on the required volume. Since I have a Vortec pump and run less than HALF the stock pressure with it, I don't doubt I could run 450+hp with it, granted I don't know what the actual capacity is @ said pressure.

 

[ATL Regal]

OK, here is where I am.

I'm in the house with the entire L31 engine harness trying to figure out how to make it fit.

The best that I've come up with is to modify the pins in the Blue, Red, Black , & White ECM connectors, removing unnecessary pins from them. Then I would need to find a way to supply it with (fused?) power.

I have searched high and low and have not come up with anything regarding the proper pinouts for my application. The closest I've come is this write-up:
http://www.s10forum.com/forum/f10/possi ... ky-441468/

But it's for a v6 to v8 swap and the connectors that he's referring to don't match up with the ones I have.

I have a Haynes Manual, but it's hard to follow as far as the wiring diagram goes. It doesn't specify which connector (blue, red, black, or white), just the color of the wire, where it goes, and what it controls. With 4 different connectors there are multiples of the same wire color combo.

 

[ATL Regal]

Sent from my DROID BIONIC using Tapatalk 2

 

[ATL Regal]

Red connector

Pin #'s color(s)
1. Blank
2. Blank
3. Black
4. Yellow w/ black stripe
5. Blank
6. Lt. Green
7. Brown
8. Blank
9. Green w/ white stripe
10. Brown
11. Lt. Green w/ black stripe
12. Red w/ black stripe
13. Lt. Green w/ white stripe
14. Lt. Blue w/ white stripe
15. Black w/white stripe
16. Yellow w/ black stripe
17. Blank
18. Blank
19. Blue
20. Blank
21. Lt. Green
22. Tan
23. Yellow
24. Blue
25. Blank
26. Black
27. Yellow w/ black stripe
28. Yellow
29. Lt. Green w/ black stripe
30. Lt. Blue w/ black stripe
31. Lt. Blue w/ black stripe
32. Pink w/ black stripe

Sent from my DROID BIONIC using Tapatalk 2