1995 540i fuel line diameter [Archive] - Bimmerforums

vroomZOOM

01-05-2018, 05:40 PM

Hello
I am repairing my 540i after it sat over grass for two years and a lot of things have to be replaced, including the brake and fuel lines. the lines in the car are pretty bad, maybe they are even the original steel ones. Because I have limited time in the shop, I would save time if I could find out the diameter and length of the lines versus going to the trouble of taking them apart. does anyone know what kind of tubing is used in the 540i and how long is it?

Thanks :)

shogun

01-05-2018, 05:47 PM

Use your VIN and then check on www.realoem.com and buy the fuel lines by the meter. Usually it is mentioned like Fuel hose 6X11MM , Fuel hose 8X13MM , length you can measure on the car.

ross1

01-05-2018, 05:50 PM

Fuel line rubber hose is 8mm I.D. so the pipe ought to be 8mm also.

vroomZOOM

01-05-2018, 06:07 PM

can I put rubber hose and is it better or should I stay with the steel lines? people say steel lines will outlast the car

shogun

01-05-2018, 06:14 PM

no need to replace steel lines, leave the steel lines where they are, just replace the fuel hoses, fuel hoses PLUS vacuum hoses. Plus probably some of the hydraulic hoses.

vroomZOOM

01-05-2018, 06:27 PM

the fuel and brake lines are made of steel and have rusted away, and I can't find what diameter they are

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the rubber part to the charcoal canister and to the steel tubing is OK

vroomZOOM

01-05-2018, 06:40 PM

hmmm... I have 3 fatter lines, two of them the diagram has verified as fuel, one on the left, and one on the right, and 2 brake lines on the left side. there is also some kind of line that looks in diameter like the fuel lines but it is not in the diagrams. I looked on the website mentioned above and it doesn't seem to have the specs for the lines. sorry, forgot to mention that these lines are on the underside of the car running to and from the engine compartement.

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sorry... also forgot to mention that by lines I meant the steel tubing

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will try post some pictures on monday, though I will have to take it apart by then

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serial # is GF32788

shogun

01-05-2018, 06:53 PM

Based on the VIN here some links
http://www.realoem.com/bmw/enUS/partgrp?id=HE63-USA-01-1995-E34-BMW-540i&mg=13
http://www.realoem.com/bmw/enUS/partgrp?id=HE63-USA-01-1995-E34-BMW-540i&mg=16
brakes http://www.realoem.com/bmw/enUS/partgrp?id=HE63-USA-01-1995-E34-BMW-540i&mg=34
power steering, ASC+T http://www.realoem.com/bmw/enUS/partgrp?id=HE63-USA-01-1995-E34-BMW-540i&mg=32
in case the car has rear self leveliing shocks, see here for the lines http://www.realoem.com/bmw/enUS/partgrp?id=HE63-USA-01-1995-E34-BMW-540i&mg=33

vroomZOOM

01-05-2018, 07:00 PM

hmmm... how could I distinguish self leveling shocks? they look kinda low,but is that normal with the engine not running?

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it says fuel pipe on the website, but no specs or anything

shogun

01-05-2018, 07:06 PM

Self levelling shocks have a hydraulic hose connection at the bottom and on the rear axle there is a regulating valve which lowers or raises the rear. These are SLS/LAD shocks http://www.bimmerboard.com/forums/posts/1261417/
Here is the workshop manual https://www.bmwtechinfo.com/repair/main/

"t says fuel pipe on the website, but no specs or anything">>>which one, post the link to realoem where you found it

vroomZOOM

01-05-2018, 07:36 PM

http://www.realoem.com/bmw/enUS/showparts?id=HE63-USA-01-1995-E34-BMW-540i&diagId=16_0186

number 2 and 3 are the pipes that are shot

shogun

01-05-2018, 07:45 PM

These you can buy ready made from the dealer or other online shops, for example here with pics, check with realoem which one is needed
https://www.ecstuning.com/b-genuine-bmw-parts/inlet-pipe/16121182171/
https://www.ecstuning.com/b-genuine-bmw-parts/fuel-return-pipe/16121182418/

ross1

01-06-2018, 05:50 AM

can I put rubber hose and is it better or should I stay with the steel lines? people say steel lines will outlast the car

Not a good idea to use rubber hose under the car. Clearly steel lines don't outlast the car.
My advice is to buy a spool of copper/nickel tubing which is easier to bend, flare and will outlast the car, and a flaring tool to make your own lines. The place where they usually rot is near the rear sub-frame, replacing them with the pre-bent factory parts(without mangling them anyway)requires you to drop the sub-frame and fuel tank, a big job.
You can patch in sections, just be sure to use flare unions and not compression fittings.

vroomZOOM

01-06-2018, 11:04 AM

This is what I am trying to figure out... I want to buy spool of that copper/nickel tubing but I am trying to fine out the diameter so I know which size to buy

thanks

ross1

01-06-2018, 02:22 PM

I think this was answered in post #3

vroomZOOM

01-06-2018, 08:48 PM

what about the brake lines that run there? they are thinner

Layne

01-07-2018, 12:01 AM

Every BMW brake line I've ever seen was 3/16" (probably actually 5mm originally). You can buy generic un-bent lines with the ends already on them (M10x1 bubble flare). It's not that easy to make your own bubble flares and the tool is expensive. Realoem will probably tell you what length of un-bent line has superseded the original pre-bent line, or perhaps some of the pre-bent ones are still available. You can only find un-bent lines up to 5ft locally, but you can find longer ones in coils online.

ross1

01-08-2018, 08:10 PM

vroomZOOM

09-12-2018, 09:12 PM

well, im back after a while to work on this car. people say its junk but I swear its going to be valuable someday and I dont want a zf transmission going to the scrapyard, so well, I work on this car. I must have been really pissed about the lines rotting out when i went to buy new tubing - oops bought stainless steel fuel line. yes its meant to be bent but its harder to bend. I have a full shop worth of tools, like benders and bubble flaring tools and lathes and etc but my question is, in practice, how many things do I have to remove to be able to properly bend and install the fuel line? Im just wondering if any of you have done it and if it necessitates the removal of the axle or something. also, there are clips under the car that hold the lines. well, every single screw is rusted tight - had to use the drill treatment. now there is a stub with the remainder of the screw sticking out. tried the vice grips to remove it and POP!the whole stud with the thread in it and screw went in one piece, leaving a round spot on the body - now what do I do? do I weld a stud on or is there a solution that someone made up who has been in this situation before? one last curiosity question - from each wheel there is a white fairly thick plastic tube - whats that for? thanks

vroomZOOM

09-12-2018, 09:16 PM

Not a good idea to use rubber hose under the car. Clearly steel lines don't outlast the car.
My advice is to buy a spool of copper/nickel tubing which is easier to bend, flare and will outlast the car, and a flaring tool to make your own lines. The place where they usually rot is near the rear sub-frame, replacing them with the pre-bent factory parts(without mangling them anyway)requires you to drop the sub-frame and fuel tank, a big job.
You can patch in sections, just be sure to use flare unions and not compression fittings.
luckily I dont have to drop the tank, there is rubber hose going to the side where the filters are, and from there it is metal. now the guy at the parts store says FLARE UNIONS should NEVER be used on a car?I agree with you and not that guy! If I have to drop the sub frame I will, but yes its going to be one heck of a job, and im limited on time in the shop

ross1

09-13-2018, 10:51 AM

luckily I dont have to drop the tank, there is rubber hose going to the side where the filters are, and from there it is metal. now the guy at the parts store says FLARE UNIONS should NEVER be used on a car?I agree with you and not that guy! If I have to drop the sub frame I will, but yes its going to be one heck of a job, and im limited on time in the shop

So, what does this knuckle dragging counterman suggest?
Perhaps if he had ever serviced a car, rather than tapping away at an electronic parts data base and chatting up amateur wrenchers, he might have noticed that virtually every hard line connection from the factory on essentially every car made uses flare connections. Moron!

vroomZOOM

09-13-2018, 08:56 PM

ya, duh

moroza

09-14-2018, 02:36 PM

8mm

I just replaced my fuel hard lines. The subframe "has" to come out but 1. it may be possible to wiggle the lines around it, and 2. if you're making your own, you could make them in two sections joined by a short flex line for easier assembly. Also, you might be able to just lower the subframe without removing it. The fuel tank does not need to come out regardless.

Those screws are a pain, eh! Soak in PB Blaster overnight and hope for the best, but I still broke two. If you actually broke a hole in the body, you need to close it somehow. I suggest removing the carpet, sanding/painting the bare metal at the hole (enlarge as needed), then installing this stack: M4x0.8x30mm (give or take on the length) stainless steel bolt, big washer, RTV, another big washer with RTV, a nut with threadlocker, then the plastic line bracket, a smaller washer, and a nut with anti-seize.

vroomZOOM

09-20-2018, 08:41 AM

ok, so now I have the new line in and im trying to get fuel pressure at the engine but there is none. will the pump turn on if I turn the ignition to on without the engine running or do I have to crank the motor to get fuel pressure

vroomZOOM

09-21-2018, 11:22 AM

well now i have determinted that there is no power going to the fuel pump fuse from the electronics box, even when I bypass the relay. the diagram says that there is some cooling fan there that is connected in there. does anyone know where the junction is and how to get at it?

ross1

09-21-2018, 12:08 PM

fuel pump relay is served by the DME relay, start there.
Does it have spark when cranking?

vroomZOOM

09-21-2018, 04:55 PM

fuel pump relay gets power though, and gives power to the cooling fan and fuel pump through the green violet wire. in my case it exits the relay but doesnt reach the fuse box at the other end. check out the pic 637263

vroomZOOM

09-25-2018, 08:29 PM

ugh... felt pretty dumb after realizing two different wires are the same colour, still working on it, now I am getting voltage... close but still no cigar

ross1

09-26-2018, 03:17 PM

pin 86(red/wht wire) at the FP relay should see 12v+ from the DME relay while cranking. If not connect a test light between the brown wire corresponding to pin 85 on the DME relay and 12v +, when cranking the light should glow, if not no signal from the DME for fuel/spark. Probably because not seeing engine rotation from the crank sensor, IE dead crank sensor

vroomZOOM

09-26-2018, 07:57 PM

well I am making progress... I jumpered the pump relay and I get voltage at the pump now... but it doesnt seem to run... at least I dont hear anything and there is no gas coming out of the fuel line at the engine. seems like the pump is dead... will go to bimmer heaven and get one

vroomZOOM

09-30-2018, 06:50 PM

just one quick question - we ran into an arguement at the shop as to how the program is stored in the computer. is it a tape, hard drive or something else?

moroza

09-30-2018, 08:53 PM

You mean the engine tune? Volatile* solid-state memory on transistorized circuits, a la computer RAM.

*Means that it needs a constant supply of voltage to remain active, unlike a hard drive or the basic engine software. That's why disconnecting the battery resets fuel trims and such.

Tape https://www.bimmerforums.com/images/smilies//rofl.gif

ross1

10-01-2018, 09:50 AM

https://upload.wikimedia.org/wikipedia/commons/3/3c/IBM_729_tape_drives.agr.jpg (https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwjz7OaLseXdAhXl5IMKHXbkDTUQjRx6BAgBEAU&url=https%3A%2F%2Fcommons.wikimedia.org%2Fwiki%2FF ile%3AIBM_729_tape_drives.agr.jpg&psig=AOvVaw15MUC38a6tTAYpuAJWtAdm&ust=1538488123339204)
Bosch 3.3 DME

vroomZOOM

10-25-2018, 09:17 AM

Hello there. Back to working on this thing. I measured for voltage at the fuel pump connector and it is within spec. took the pump out, attached it to a battery and put it into a tub of water, the pump shoots out water. when i put it back into the car, there is only a slight gurgling coming from the pump area and nothing else. all the in car tests have been done with the pump relay removed and a jumper instead of it. I have the pieces, but when i put things together it doesn't work! has anyone been in this situation? any help appreciated.

moroza

10-26-2018, 12:13 AM

Basic: is there fuel in the tank?

Advanced: Test for voltage at the pump connector while it's running. You may have damaged wires that test ok at DMM current levels, but are kinked or otherwise messed up to the point of dropping too much voltage at pump draw levels.

vroomZOOM

10-26-2018, 08:11 AM

hmm that seems like a good idea... will check that right now. as for fuel, yes there was a couple of inches of gas in the tank when I was taking the pump out

ross1

10-26-2018, 08:21 AM

vroomZOOM

10-26-2018, 08:56 AM

ok so now ive found it... checked for power at the fuse, test light lights up good, checked with a test light at the fuel pump plug and its very dim. does anyone know any points where the wire might break or where it runs? thanks

moroza

10-26-2018, 02:38 PM

Green/Purple wire begins at the fusebox, goes through the firewall above your left foot via a large yellow connector, down along the left rocker (inside the car), into the rear seat area from the left, back out of the car behind the battery on the right through a grommet*, near but not shared with the right rear ABS cable, above the subframe, then above the tank to the fuel pump. There are no splices; the yellow connector is the only one.

*This and back are where I'd look first. Stick your test light on the wire just before it exits the interior, make sure you have a good contact, and see if it's bright there. Yes? The break is further back, as expected. No? You have bigger problems.

alang1990

10-26-2018, 08:39 PM

The wire break would usually be within 1 foot of the pump's connector.

Hey...Wait a second that might not be it at all. It could be your female pin at the connecter, or the wire just behind it. Test the wiring just one inch behind the connector first.

In fact pull the connector's boot back fully and look at all the wires just behind the plug. (like half an inch). You're going to see stripped insulation. Actually that insulation has burned off and wires are touching etc. The solution is simple. Take fish tank clear tubing, cut a short length, cut down its length and insert it over each wire with needle noose pliers. and squeeze it into the back of each connector. You get the drift.

Unless of course you can easily separate the wires and redo the insulation up to the connector's back with tape. The space is pretty tight.

vroomZOOM

10-30-2018, 08:18 AM

ok, so i have checked for power just behind the battery, and its good there, but nothing at the connector, where do I check now? thanks

alang1990

10-30-2018, 11:48 AM

The wire break would usually be within 1 foot of the pump's connector.

In fact pull the connector's boot back fully and look at all the wires just behind the plug. (like half an inch). You're going to see stripped insulation. Actually that insulation has burned off and wires are touching etc. The solution is simple. Take fish tank clear tubing, cut a short length, cut down its length and insert it over each wire with needle noose pliers. and squeeze it into the back of each connector. You get the drift.

Did you do this?

vroomZOOM

11-01-2018, 08:35 AM

yes I did. now I think it might not be the wire at all, but rather a bad ground at the tank? I ran a new wire and it still gives me the same result when I ground at the tank. when I ground at the spare tire bolt though, it works.

mrgraybeard

11-01-2018, 11:39 AM

The tank itself isn't really grounded to the chassis. The fuel pump ground is inside the cabin, under the rear seat.

alang1990

11-01-2018, 08:18 PM

The tank itself isn't really grounded to the chassis. The fuel pump ground is inside the cabin, under the rear seat.

So op you have a ground wire that goes from the go connector to the abovementioned ground point. Check continuity between both.

Watch some YouTube videos on to to check continuity trace wiring breaks etc.

vroomZOOM

11-13-2018, 07:55 AM

well it now seems that the wiring issues are resolved, but now the pump doesn't work. I took it out of the tank and attached it to a battery, nothing. how is this that the pump was working one moment and then suddenly stops? I hope I haven't fried it? thanks

vroomZOOM

11-15-2018, 09:12 AM

so i wanted to hear the engine run so I tried connecting a fuel injector cleaning pressure tank to the fuel rail and I turned it up to 50 psi. tried cranking the motor, it cranks but doesnt even try to fire. what is happening now? man this car is frustrating. will try to install ISTA and diagnose it, will any errors show up or not?

moroza

11-15-2018, 10:18 PM

Hang in there; best believe this car at 23 years is a lot easier to fix than a new one will be in 23 years.

Lacking an obvious thing to try, do the traditional check for spark and fuel (injection, in this case, not supply): remove a sparkplug, keep it in its ignition coil, ground it to the chassis with a jumpercable, crank and see if 1. it sparks, and 2. if fuel shoots out of the cylinder. Try to keep the plug away from the cylinder and the test length to a minimum, for fire hazard reasons.

vroomZOOM

11-20-2018, 08:57 AM

ok so although its freezing out here I have tested for spark, and i could have probably seen it from 50 feet away. there was a clear bright spark. will check with a noid light for the injectors opening. if anyone has any ideas let me know.