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Discussion Starter #1
I'm new to mechanical fuel injection, just wondering what fuel pressure/flow these fuel pumps produce. Canadian market '76 and '78 Alfetta 2L sedans.

Thanks!
 

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I remember something about the under the car pump supplying 80 psi to the Spica pump. Others may know for sure.
 

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re: SPICA system-
The fuel pressure switch (red light on the dash) turns off at 7-9 psi so 80 psi is a little high.
If the light stays on after start up then check out cause of low pressure.
#1: check filter(s), the most likely problem
 

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I do remember reading some time ago that the pump was supposedly rated at something like 80 psi in order to provide the very high flow rate required for fuel and pump cooling. The actual pressure may not be that high in the line; however, a very high volume pump is required in order to make sure the flow rate is high in this bypass fuel line system, ie, the excess fuel returning to the tank, providing the necessary cooling.

Just think, if you have a Montreal, you get to use two of these no longer manufactured pumps.
 

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I cannot find anything stating fuel pressure. However, the Ingram Manual says the fuel pump should deliver a minimum of 0.6gpm. 0.5gpm or less and you should replace the pump. So, like Del stated, gpm is the important thing as a faulty pump can have good pressure but not delivering the quantity of fuel required.
Several sources state if the pump has low pressure "have it serviced".
Centerline and Spruel Motorsports sell replacement fuel pumps. The fuel pump that came with SPICA systems does not exist so a different pump is supplied.
The fuel injection pump does operate at huge pressure, 350psi per Ingram. With that high pressure that's probably why Ingram recomends servicing the injectors every 25 years.

Sources: Ingram SPICA Manual (a must have)
Alfetta GT Manual from Jim/Papajam (worth the money!!)
Braden's book
Haynes Manual
ALFA SPICA Maintenance Manual

(boy, I sure do have a lot of Alfa reference stuff. I should therefore be better at repairing my cars!!??)
 

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Discussion Starter #7
I apologize, I'm pretty new to Alfa's and mechanical fuel injection to begin with.

What your saying is the pump is a low pressure, high volume pump that feeds the mechanical injection system that has it's own pump that increases pressure?
 

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No appologies needed.
You are correct in the system description. The big thing that turns by a tooth belt is the SPICA Fuel Injection pump. (SPICA pump)
Notice the metal lines that feed each injector.
Note: The SPICA pump has only a few areas that can be adjusted. There is a great book from Ingram Enterprises that describes them.
Also there are great posts on this bb with the similar descriptions.
If you don't have any instructions DO NOT think about messing with anything on that pump. ASK ANY OF US HOW WE KNOW. A few small screw ups and you have a poor performing car. Know what you are doing and in a mater of an hour or so you can get a non running Alfa running.
A lot of good info on this bb comes from John/Roadtrip.
An interesting side note: NASA has looked at the SPICA pump and determined that the only thing more complicated is the Space Shuttle. Only the Shuttle has fewer moving parts.:D:D
 

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Fuel pump pressure

I knew I saw it someplace.
Ingram's Fuel Supply Diagnostics, from his website. Available for download.
10-20 psi, ideal is 15-18 psi. 10 psi on battery power only.
The SPICA fuel system has a pressure relieve valve that prevents over pressure. 1975 and later cars the PRV is part of the fuel pump, on pre 1975 it is part of the front fuel filter housing.
The PRV may be why replacing the fuel pump requires caution and a PRV valve someplace. MY PT Cruiser operates at 53 - 63 psi. And my '79 350CI Chevy van motor manages 9 mpg at only 4.5 - 9 psi.

I knew I saw it someplace!
 
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