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Discussion Starter · #1 ·
so i have a 86 cabriolet . has new fuel pump. new filter, ive cleaned lines and injectors, all clear. also i made sure my flapper is moving nice a free. i took the distribution block apart cleaned and checked all ports all clear, and the plunger moves nice and free in the center of the distribution block. . anyone have any thoughts. ??
 

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Fuel goes in the fuel distributor at a high pressure. The distributor will regulate that pressure around 5 bar. The system runs on that pressure and when the plunger is lifted, the fuel will exit the distributor to the fuel injectors. The injectors have a valve that will open up around 3 bar. Once they open up, they will spray fuel.

It is fairly simple. If the fuel is going to the distributor with enough pressure and is regulated properly and leaves the distributor with enough force, it will open the injectors to go out. My bet is the plunger is not moving, the distributor is junk, or the fuel pressure is not good enough.
 

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Discussion Starter · #3 ·
im wondering if its not enough pressure, cause the plunger moves nice and free. and i completely disassembled and cleaned the block. it had no junk in it. but the pump is new? could the warm up valve have anything to do with it?
 

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No.

CIS is a very easy system to deliver fuel to an engine. The biggest issues is that people will not take the time to totally understand how it works. I suggest to Google it and see how it works. The injectors are either all plugged [highly doubtful] or there is not enough pressure to open them. Since the fuel comes from the fuel distributor, I would start there. I would buy a fuel pressure gauge, before I thought about working on it. Just because it's new does not mean anything. You know what new means [Never Ever Worked].
 

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Two things, if you installed the wrong fuel pump, externally they look the same, but if the pump is for Digi it will only put out about 50 PSI, you need a pump that puts out a min of 80 PSI, the guy at the parts store doesn't know the difference and the manual he's looking it up in doesn't tell him specs. If you're trying to test flow by jumpering the fuel pump you need to lift the flow plate, all the way down shuts off flow, keeps the injectors from leaking into the intake after you shut the car off.
 

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Fuel pumps do not make pressure. They just move fuel. The regulator restricts the fuel flow and that is where the fuel pressure is built. A lot like a dam in a river.

The CIS fuel pump is what you need since it is designed for the extra load. Digi fuel pumps will work and will develop more than 50 psi.

Something is not right for certain. Maybe the fuel pressure regulator is stuck open causing low enough pressure so the injectors do not open.
 
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