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1974 Alfa Romeo spider
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Discussion Starter #1
I recently bought a 1974 Spider that appears to be a California car so everything is original including the grill overider and all of the fuel injection. I got the car after someone I knew was given the car and got frustrated that he couldn't get it started. I got it started with a fresh set of plugs, wires, all new fuel hoses, rear fuel filter & checking the injection system. After setting for a couple of weeks, it would barely start and run very poorly when it did start. I removed the fuel tank and had it cleaned and lined after the new rear fuel filter appear to be clogged. Now it appears that the original 2 port Bosch fuel pump has problems. I have read several other post and have a few questions; first, is there a fuel pump that has the same specs as the original? I know about the Bosch 070 (l-jet) but I don't like the idea of soldering up and redrilling orifices. Second, there is a guy that uses a Bosch 044 (CIS) fuel pump with a Holly fuel pressure regulator. I like this idea, but he stated that he designed it with the later 3 port Bosch pump in mind. Will this work with the older 2 port design? Also, if I choose to trash the Spica fuel injection system, can this setup be dialed down to work with a set of Weber like God and Jano intended? Finally, back in the 70's, I remember reading in Alfa Owner that there was a high pressure Holly pump that came with a regulator that everyone was using without the regulator. Anyone know what that was all about?
 

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Cort,

Your 74 almost certainly came with the 3-port pump. Somewhere along the line, someone has replaced it with a two port.

It’s a bit out of my personal experience, but you may have a car with the regulator built into your main filter assembly up in the engine compartment. If that’s the case, you can probably replace your dead pump with an 044, do a pressure check, and go on your way.

For more detailed help, pictures of your pump, showing part number on it, if possible, and a picture of your main fuel filter assembly up front.
 

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BTW, the Centerline pump description has what I believe is a misleading description of what must be done.
 

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1974 Alfa Romeo spider
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Discussion Starter #5
20191113_145416.jpg
This is the filter that I have. DPeterson3, I wanted to hear more about your 044 - fuel regulator combo. I understand that you shouldn't rely on the pressure relief in the filter. I am thinking if I put a tee in the return by the tank, I can use your arrangement. If I finally have enough of this fuel injection, do you think the regulator could be dialed down to a pressure suitable for webers?
 

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I’ve never played with the filter-regulator system. I don’t even know if it’s an actual regulator or just where Alfa mounted an orifice. But, here’s my thoughts...

Keep the Spica. Wonderful system, but no different than brakes or engines, sometimes It’ll need a major overhaul.

First, find out if the regulator is an actual regulator or where the calibrated orifice is mounted. You’ll want to retain the orifice, as that is what defines the necessary overhead for cooling.

Otherwise, yes... you use a tee for the Holley regulator and Spica return line leading to the tank return.

Using the original orifice, you should be able to adjust the pressure to the desired 15-17 psi. If necessary, you can enlarge the orifice to put the regulator comfortably within its adjustment range.

There is some fabrication required to make it all neat, but it’s at the bog-simple range of difficulty.

If you’re interested, I’ve got an Evil Energy 044 and spare Holley regulator. I could fab it up for you at my cost + tip. 😎
 

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The banjo bolt on the return line - the one at left on the fuel filter with a rusty head on your photo - contains a 17 psi regulator valve. That car was built with a 2 port pump. With the Alfetta in 1975, Alfa used a 3 port pump with a built in regulator - the third port is a return line.

Check this guide for more info. The Bosch pump is normally very reliable. It is a positive displacement roller pump. If it spins, it moves fuel. Perhaps crud is playing havoc with fuel delivery.

Usually, the weak point of the Spica system is the thermostatic actuator = the bulb in the intake manifold with a thin brass tube that goes into the Spica pump. As engine temperature goes up, it pushes a device inside the pump to weaken the mixture. Usually, after a few years, they don't push anything. You have a choice of adjusting it si the engine is not too hard to start, but always rich, or hard to start, and not so rich.

If you end up using Webers, you can keep the pump and filter arrangement by gutting out the pressure valve out of the banjo bolt. The free return to the tank leaves just enough pressure for the Webers to be happy. I've used it on more than one Alfa.
 

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Now it appears that the original 2 port Bosch fuel pump has problems.
What problems are you experiencing with the pump? Does it come on? Is it dead? Low pressure.? Have you checked your ground connection?
I agree with Yves, these old Bosch pumps are very reliable. I still have my original pump in my 72 Alfa and other Alfa's.
They are also serviceable. I have serviced dead or weak pumps before with great results. They may be some crud in the pump from before you had the tank cleaned out which may be causing your fuel delivery issues.
 

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See the post below for a company that can rebuild your fuel pump.

 

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Discussion Starter #10
What problems are you experiencing with the pump? Does it come on? Is it dead? Low pressure.? Have you checked your ground connection?
I agree with Yves, these old Bosch pumps are very reliable. I still have my original pump in my 72 Alfa and other Alfa's.
They are also serviceable. I have serviced dead or weak pumps before with great results. They may be some crud in the pump from before you had the tank cleaned out which may be causing your fuel delivery issues.
I would love to rebuild and keep my original pump. After I got the low pressure light to work right, I would turn the key on and it would take an eternity for it to go out. If I just tap the key to start, the light would light back up. If you hold the throttle down, it will start but run very poorly.
 
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