323i euro fuel pump replacement

[benz-tech]

Hey all, I need to replace the noisy fuel pump on my ‘85 323i. It doesn't seem to follow the normal early-dual/late-single pump configuration. I verified it has only has one pump( I pulled the sensor to verify), and a 55L tank (with crossover pipe). The p/n from realom is 16141178751 but the only site that matches that exactly is a URO fuel pump from autohausAZ but I’d like it to last longer than 6 months. It looks like a standard late pump. Anyone have experience with this? I think I’m just going to order a late pump but figured I’d ask first

[82eye]

Hey all, I need to replace the noisy fuel pump on my ‘85 323i. It doesn't seem to follow the normal early-dual/late-single pump configuration. I verified it has only has one pump( I pulled the sensor to verify), and a 55L tank (with crossover pipe). The p/n from realom is 16141178751 but the only site that matches that exactly is a URO fuel pump from autohausAZ but I’d like it to last longer than 6 months. It looks like a standard late pump. Anyone have experience with this? I think I’m just going to order a late pump but figured I’d ask first

to confirm - you have one pump only in the tank ? is it possible your car has been converted at some point to the later fuel system ?

it's easy to mod the in tank pump for a cheaper alternate if you pull the specs on the original or uro replacement and match to another electric in tank pump. i used a kitten brand spectra for a 6 cyl mustang when i replaced the pump in my car. a chevy vega replacement used to work for the in tank pump in e cars, it may work for you as well. can save a fair bit.

[benz-tech]

The only pump I have is outside in front of the driver rear tire. Sounds like it’s the opposite of a late car. The pump subs to a dual pump p/n which means it really should have a lift pump. I’ll look into either adding a lift pump or putting a hp pump in the tank and tossing the external pump. I’ll need a new tank sender/pump assy and then run wires to it

[82eye]

The only pump I have is outside in front of the driver rear tire. Sounds like it’s the opposite of a late car. The pump subs to a dual pump p/n which means it really should have a lift pump. I’ll look into either adding a lift pump or putting a hp pump in the tank and tossing the external pump. I’ll need a new tank sender/pump assy and then run wires to it

if you have an external pump you also have an internal. it's a non option. an external pump alone can't pull from the tank by itself. first determine which pump is failing.

the updated system is an in tank pump only.

[benz-tech]

if you have an external pump you also have an internal. it's a non option. an external pump alone can't pull from the tank by itself. first determine which pump is failing.

the updated system is an in tank pump only.

Well, apparently it was an option on the unicorn 323i. I do NOT have a pump in the tank. The sensor has a pick up and return line and sensor only. It matches the picture in realoem for this car. As long as the hole in the tank is the same size, I will source a 55L early US sender/fp assembly and add wiring to the new tank pump from the existing external pump. And I may just remove the external pump altogether to update to late version hp in-tank.

[82eye]

Well, apparently it was an option on the unicorn 323i. I do NOT have a pump in the tank. The sensor has a pick up and return line and sensor only. It matches the picture in realoem for this car. As long as the hole in the tank is the same size, I will source a 55L early US sender/fp assembly and add wiring to the new tank pump from the existing external pump. And I may just remove the external pump altogether to update to late version hp in-tank.

is the fuel getting lifted out of the tank currently? or is there a gravity feed line off the bottom of the tank?

there are generic external electric fuel pumps you can mod in to avoid the bmw tax. you have to match the flow rate to the old one, but they are not hard to use. most are smaller than the bmw pump so you'll need to be creative for mounting.

edit : TRE lists an external pump delivering 145lph at 43psi/3bar as the generic replacement spec. it seems to be in line with the replacement pierburg pump spec for the same car.

[iansane]

Well, apparently it was an option on the unicorn 323i. I do NOT have a pump in the tank. The sensor has a pick up and return line and sensor only. It matches the picture in realoem for this car. As long as the hole in the tank is the same size, I will source a 55L early US sender/fp assembly and add wiring to the new tank pump from the existing external pump. And I may just remove the external pump altogether to update to late version hp in-tank.

You're in the US, yeah? If so, that's probably the route I'd go for later replaceability. Remove the external and go with an internal early hanger/sensor(I'd double check the resistances between your sender and the replacement one). But just remember that the stock early in tank pump won't supply the engine by itself. It's meant to be a low pressure lift unit. It isn't that hard to hang a late model pump or generic "performance" replacement on that early hanger. I've done that on a few swap cars. If you do so, also remember that if you use fuel hose to connect it up, it has to be submersible fuel hose other wise it will deteriorate quickly.

[benz-tech]

It’s getting lifted out of the tank through the internal lines in the sensor, but I suppose there could be a secondary external pump hiding somewhere that’s not on realoem. Lifting up out of the tank is a terrible way to supply fuel.

[benz-tech]

You're in the US, yeah? If so, that's probably the route I'd go for later replaceability. Remove the external and go with an internal early hanger/sensor(I'd double check the resistances between your sender and the replacement one). But just remember that the stock early in tank pump won't supply the engine by itself. It's meant to be a low pressure lift unit. It isn't that hard to hang a late model pump or generic "performance" replacement on that early hanger. I've done that on a few swap cars. If you do so, also remember that if you use fuel hose to connect it up, it has to be submersible fuel hose other wise it will deteriorate quickly.

Yeah I think updating to the later version will be the best route for me to take.

[82eye]

Yeah I think updating to the later version will be the best route for me to take.

long term that's the better option. it simplifies the system. you can still work with what is currently installed though.

[82eye]

It’s getting lifted out of the tank through the internal lines in the sensor, but I suppose there could be a secondary external pump hiding somewhere that’s not on realoem. Lifting up out of the tank is a terrible way to supply fuel.

a closer look at your car on real oem shows they did it both ways depending on the market. it's a hangover from e21 land.

edit : what psi/bar is your fpr set for? if you update you'll need to match the pump for the flow rate and psi/bar for the injectors. it will be different from the 325i.

[benz-tech]

a closer look at your car on real oem shows they did it both ways depending on the market. it's a hangover from e21 land.

edit : what psi/bar is your fpr set for? if you update you'll need to match the pump for the flow rate and psi/bar for the injectors. it will be different from the 325i.

So it gets a little complicated from here. I am acquiring parts to go with a stroker 2.7, motronic 1.3 etc, but that’s a ways out. I think, in the interim, I’ll add a used early in-tank pump/sender and see if it quiets down the main pump. Technically the FPR sets the pressure as long as the main pump isn’t way too strong so I should be fine. LE jetronic likely runs slightly different fuel pressure but I haven’t researched yet since there is very limited info on the 323i in the E30

[e30davie]

Theres plenty of info around if you look. But you wont find much on the internet as they didn't come in the usa.

https://e28goodies.com/wp-content/uploads/2016/11/Bosch-L-Jetronic-Injection-Technical-instructions.pdf

Admittedly it does say "2.5 bar or 3bar" for the fpr. but these generic manuals contain lots of useful nuggets of info.

I have a 323i and someone has just replaced my pump with a gineric bosch external pump, and plumbed it up to suit. Mine is also noisy and im fairly sure its because its sucking fuel out of the tank. Pumps like a bit of pressure on their inlet to stop making noise. I have always intended to add an internal lift fuel pump in the tank, but never got around to it.

The bosch 910 has always been my go to pump for conversions on NA engines. its cheap as chips here in Australia as they came on all the Holden commodores, its rated at 130L/hr at 5bar. So I guess a bit more flow at 3bar. if its good enough for a 3.8L v6 ecotec its good enough for a 2.3L.

[iansane]

a closer look at your car on real oem shows they did it both ways depending on the market. it's a hangover from e21 land.

edit : what psi/bar is your fpr set for? if you update you'll need to match the pump for the flow rate and psi/bar for the injectors. it will be different from the 325i.

I was going to say the pump isn't going to have any effect on the FPR/injectors in this situation but after looking at the real OEM diagrams I'm not sure. It has all the rail mounted FPRs grayed out. The 323 does have a fuel rail mounted FPR, correct? If so, it doesn't matter what pump you run as long as it's not dual a1000's with -8 line or something crazy that would overpower the regulator.

Jerry, does your car have this weird fuel "separator"? #2? That's crazy.

[KneipeMeijer]

From what I know the 323i will only have one fuel pump and that is the external one the big thing in the fuel tank is only your fuel level sender, the fpr is like normal on the rail, but it is only 2.5bar. It is easy to convert to an in tank pump, just pick up a pump housing with return, a pump (I used a walbro 255) and a fuel level sender (16141152266). From there on, you only have to extend your wires from your external pump and make a new connector for the sender. I can make some pictures tomorrow if you need some.