Fuel pump spec for 1979 635csi (M90 L-Jetronic)

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msoft
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Location: Sweden

Fuel pump spec for 1979 635csi (M90 L-Jetronic)

Post by msoft »

I'm about to order a fuel pump for my 1979 635csi (M90 L-Jetronic). Facts:
-Have removed old one which is called 0580464013.
-RealOEM suggests 16141178751 but at the same time says "Only in conjunction with pre-supply pump" but there is no in-tank pump in my car.

I lean towards a BOSCH 580464070 or equivalent that gives 3 bar and 130 liters / hour. Is this a correct spec?

Within which limits should you be with pressure and flow for it to work well in this car?

Thanks'
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Ralph in Socal
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Re: Fuel pump spec for 1979 635csi (M90 L-Jetronic)

Post by Ralph in Socal »

I'm not sure what is required pump pressure but 3 bar may be low. The M30B34 fpr is usually 3 bar so I would think you need to go above the regulator set point. I know you have M90 but they were very similar setup. Check your fpr rating for confirmation as it may be 2.5 bar

Required volume is +1 liter per minute out of the fpr outlet. 130 l/hr is double so that's good

Ralph
There is a very fine line between "Hobby" and Mental Illness.

85 635csi Zinno Auto
84 528i Euro
83 635 Euro Arktik
81 528i Kastanien 5-speed
88 528e Bronzit (Granpa Car)
86 535i Auto (For Sale)
81 633 csi (retired)
msoft
Posts: 35
Joined: Thu Jun 30, 2022 1:48 pm
Location: Sweden

Re: Fuel pump spec for 1979 635csi (M90 L-Jetronic)

Post by msoft »

Thank you for Ralph for your input. RealOEM says I have the 13531263782 FPR which is 2,5 bar. Actually I have a spare BOSCH pump 0580254909 with 5 bar and 148 liters / hour. What are the risks going to high on these values?
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Ralph in Socal
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Re: Fuel pump spec for 1979 635csi (M90 L-Jetronic)

Post by Ralph in Socal »

I wouldn't do it. Risks are blown fpr to blown hoses and vehicle fire. Often called a carbeque here in Cali

Ralph
There is a very fine line between "Hobby" and Mental Illness.

85 635csi Zinno Auto
84 528i Euro
83 635 Euro Arktik
81 528i Kastanien 5-speed
88 528e Bronzit (Granpa Car)
86 535i Auto (For Sale)
81 633 csi (retired)
msoft
Posts: 35
Joined: Thu Jun 30, 2022 1:48 pm
Location: Sweden

Re: Fuel pump spec for 1979 635csi (M90 L-Jetronic)

Post by msoft »

Wow, don't want that :D. Maybe the BOSCH with 3 bar and 130 liters / hour is a good option after all. When searching for equivalents to 0580464013, I get a couple of 4 bar options as well. One is MAGNETI MARELLI 313011300065 with 120 liters / hour.
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