What's the best recommended fuel system setup on a 325e?

[emuguru]

1986 325e Automatic Stock (Or trying to get to stock at least)

I notice there is a damper on my fuel line that looks terrible, I have a charcoal canister, a fuel strainer/separator? An inline pressure regulator by the fuel tank, and still have not found the actual fuel filter.
My questions are, do people normally delete the NLA components such as the canister, strainer and damper? Or do they use them until they completely fail? Has there already been a write-up on recommended fuel setup?

[82eye]

all i can add is a lot of folk update to the later single in-tank pump fuel system as it is less complicated. i can't comment on the e-cars directly though.

edit: this thread may answer some questions - https://www.r3vlimited.com/board/for...expansion-tank

[moatilliatta]

STOCK. Can get damper new, will be "OK" without it.

[reelizmpro]

I've only seen people delete the damper. If the fuel filter isn't in front of the driver rear wheel, it is in the engine bay on the drivers side.

[emuguru]

I think I wrote the wrong part. I was assuming the part called a damper is just an inline fuel pressure regulator (#14 in diagram). There is another "Damping Unit" on mine (#20 in diagram) that I don't know is needed or not that I cannot find a proper part number for (if I take it out and clean it up I'll edit this with any part number found on it).

[82eye]

I think I wrote the wrong part. I was assuming the part called a damper is just an inline fuel pressure regulator (#14 in diagram). There is another "Damping Unit" on mine (#20 in diagram) that I don't know is needed or not that I cannot find a proper part number for (if I take it out and clean it up I'll edit this with any part number found on it).

it's a pulse damper. it smooths out the flow from the pulses created by the 2 fuel pumps. it was deleted on later cars.

[emuguru]

Ah, that explains why I can't find one lol. Do later cars still use 2 pumps or did they simplify to 1 pump? I'm thinking if they simplified that would make sense that it was no longer needed but that I should leave mine alone if it's in working order.

In related news I noticed some fuel around injector 1, and promptly pulled them and replaced the o-rings. This got rid of the tiny leak around the injector. While they were out, I did a fuel delivery test and had an unexpected result. The pressure and the amount of fuel was good (30oz in 30 seconds). But I noticed I got air bubbles flowing with the fuel every 2 to 3 seconds, about the same amount of time that I normally notice very minor rpm drops when driving. Now I am thinking the internal tank pump, or the fuel line between the internal and external pump may be faulty allowing air to enter like a straw in a fountain drink when it has a tiny hole. I will check this Friday or Saturday.

[82eye]

Ah, that explains why I can't find one lol. Do later cars still use 2 pumps or did they simplify to 1 pump? I'm thinking if they simplified that would make sense that it was no longer needed but that I should leave mine alone if it's in working order.

later i cars were single pump, and i *think* the seta was a single pump system. the single pump system never had the pulse damper and late dual pump systems also deleted it.

In related news I noticed some fuel around injector 1, and promptly pulled them and replaced the o-rings. This got rid of the tiny leak around the injector. While they were out, I did a fuel delivery test and had an unexpected result. The pressure and the amount of fuel was good (30oz in 30 seconds). But I noticed I got air bubbles flowing with the fuel every 2 to 3 seconds, about the same amount of time that I normally notice very minor rpm drops when driving. Now I am thinking the internal tank pump, or the fuel line between the internal and external pump may be faulty allowing air to enter like a straw in a fountain drink when it has a tiny hole. I will check this Friday or Saturday.

that does seem odd. it's possible it could be one of the pumps starting to fail but that's a complete guess on my part.

[emuguru]

I have done more testing, the fuel leak is back at injector 1. What I note is that air does not exist in the supply lines. I started at the pump, replaced the fuel lines with clear lines to visualize, and no air exists until just after the fuel rail.

so I went back to checking injector 1. Jumping the fuel pump relay, I find two problems with it:

1. There is fuel coming out from the bottom o-ring area. There should be no fuel going through it since it's not powered and open.

2. Any fuel going through a stuck open injector should.... I believe, be stopped by the said o-ring, and it's not.

so given the o-ring is new, I suspect the injector is stuck open and the pressure is somehow overpowering the o-ring seal at the bottom where it fits into the cylinder head.

since this is raw fuel being spilled I will not be driving until I can get a replacement injector to test.

[emuguru]

I took the injectors back out to do some more inspecting. When I apply 4psi to 5 of the injectors, they do not leak. Cylinder 1 however does, but not where I expected. I thought it was sticking open but that isn't the case. The needle valve is closing and sealing as it should. But the injector is actually leaking along the seam where the nozzle shaft comes out of the body. So it's spraying fuel outside of the o-ring completely.

[moatilliatta]

FiveO Motorsports will sell you 6 new updated genuine Bosch Units

[PEZ2]

2nd FivoO Motorsports. They have “e” injectors at a reasonable price.