post 94 e36 fuel pump/lines

Hi guys, I have a small problem with my car's fuel delivery system and I was wondering if anyone could help me. Since the day I got it, it takes a while to start (always starts enventually though). I narrowed it down to the check valve and today I decided to look at the fuel pump and fuel level sender lines to see if they are cracked and found that one is missing completely. The unit located on the passanger side has two tubes coming out of it, one of which is broken off and I can't find the fuel line that goes to/comes from it. Can't see it anywhere at all. The other line looks ok and so does the unit on the driver side (one line, nothing broken off).

The tube that is broken off is located closer to the rear of the car when compared to the other tube and is off center of the whole unit (while the one that is ok is pretty much in the center). Does anyone know what the broken part is? It can't be anything that vital since the car runs fine, just starts poorly sometimes. I do get about 18mpg (according to the OBC) on mostly city driving which seems a little on the low side, if that helps.

All thoughts are very welcome and all responses will be very much appreciated.

Reply to
andrey.ivannikov
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I don't know specifically what the broken line is, but with the car on a lift and a flashlight you should be able to find it and go from there.

Your tank has two lobes, and the fuel pump lives in the right side (passenger side for USA cars). There is an auxiliary pump that keeps the level equalized -- or the fuel pump has two pickups that it draws from -- and there is a slight chance that the broken line is the one that sucks gas from the left side of the tank. The fuel pump would have a hard time drawing gas if one of the hoses it was sucking from was open.

Frankly, I'm not sure the line you have broken off will go to the fuel pump because the pump would be sucking air all of the time and the car would constantly run as if it was running out of gas.

As you have found, the right side contains a fuel level sending unit and the fuel pump, the left side has a sending unit only. There are also lines that go to the evaproative emissions control system, and if these are broken, then all you will have is fumes venting into the atmosphere. This is a pollution problem to be sure, but is not a life-or-death issue for the car.

When you are putting the fuel pump back in, or the left side sending unit, be sure you do not crimp the rubber seal between the unit and the fuel tank. It is easy to crimp the seal, and you will have a gas leak when the tank is full. When you have the sending units removed, use a rough surface business card to clean the wiper contact on the fuel level float arm. This wiper tells the gas guage where to point, and it is known to get dirty and give false readings of Empty. You may want to use some electrical contact cleaner along with the business card to cut the black gunk that will be on the contact strip and the wiper arm. Take care to not bend the wiper arm contact.

Reply to
J Strickland

Thanks a lot for your input. I figure it would have to be the evaporation line since I had the car running at almost no gas in the tank once and it ran the same as before, nothing changed.

Would you by any chance know where exactly the line is supposed to go if it is used for emissions control system? I mean, as in, on the left side of the engine right under the hood or in the back, by the battery vent? Asking so in case the line fell off the origin and the destanation, I would know where to put it once I get it.

Thanks again for the input, really appreciate it.

Reply to
andrey.ivannikov

The line probably goes where it is supposed to go, the end you can't find is just hiding from you somewhere near the vicinity of the place where it is broken off from. There is ample hiding space between the floor of the car and the top of the tank. You may be able to snag the loose line with a coat hanger, or other suitable device.

The Bentley manual doesn't do a good job with the orientation of the photo, but it shows two lines on the right side level sensor (which also contains the fuel pump). One line is the fuel supply -- I assume fuel delivery to the engine -- and the other is the fuel return. Since your car runs, we should assume the missing line is the return. The problem here is that the missing return should be puking gas out onto the ground at idle. You should be well aware of the fuel leak if the return line is not connected to its terminus -- the gas tank.

On the post-'95 models (cars build from Jan. '95), there are two hoses shown in the picture of the tank that are described as the hoses to support the balance of the fuel load -- I described these in my first Reply. These hoses are shown as connected to the Left Side Level Sender (different for before Jan 95 and from Jan 95), but it is not shown where they go relative to the Right Side Level Sender (which is shown as the same for all models). Since you said you have the broken part on the Right Side Level Sender, I do not suspect the hoses that balance the fuel load. It's possible that these hoses actually live inside the fuel tank -- which makes lots of sense if you think about it.

Reply to
Jeff Strickland

Thanks for the update and for looking it up for me however it is still sort of a mystery. Ihave had the car idle many times on the drive way for more then just a minute and not even once did I see a spill on the ground. That gets me even more lost.

Is there a picture of the fuel and brake lines underneath the car on the driver side by any chance? I tried to see if I could find the missing fuel line and noticed that there are only 4 lines underneath the car but there is space for one more in the center, not sure if it is the one I am missing or there is too much space deliberately.

Thinking about it, maybe when the return feed broke off on the previous owner, instead of buying a new pump, he/she just connected the fuel line to the level sender on the left (driver side) of the car? I guess the only way to find out is to see how the lines behave when the engine is started and/or fish around for the missing fuel line underneath the chasis.

Thanks for the help.

Reply to
andrey.ivannikov

Driver side? Are you in a country where they drive on the wrong side of the car, ;-)

I thought you said you were having trouble with the Right Side, that's the passenger side.

There are two hoses connected to both sending units, I assume -- there are no pictures of the hoses, only the nipples on the sending units -- that one of the lines connects the two sending units to vent air to someplace, and the other carries return fuel to the tank. Of course there has to be a hose to carry fuel to the motor, but this line isn't part of your problem. My guess is that you also are not having trouble with the return line, therefore the line that you are having trouble with must the vent line, for lack of a better word.

When I had to service my fuel sending unit -- I had trouble with the left side sending unit -- I managed to drop one of the hoses and it fell between the tank and the floor of the car. It was a bitch to find and recover, but it was there. Since your sending unit broke a nipple, then I'd assume the hose is between the tank and the floor. I don't remember if you can see up from the bottom or not, and I know that looking down from the top is difficult. If I remember correctly, the hose drifted toward the front of the car, and I seem to recall that the two hoses are loosely taped together, so the hose that you still have control over should be pretty near the one you are looking for.

Yes, fishing around for the line is the next step. I suspect the previous owner didn't even know the hose broke off, and if this is true, then the hose will be hiding from you, and a fishing trip is the order of the day.

PS Go online to eBay for a Bentley Service Manual for your car. This is a great tool to have in your garage.

Reply to
J Strickland

Bah, I get confused with what the right side and what the left sides are since I remember looking at these things from the front, facing the back. I am having trouble with the passenger/right side of the car and the other side also has a hose going somewhere I am not sure where, I think I traced it down to the bottom of chasis going to the front (return line maybe?)

Also, when I looked between the tank and the floor of the car from the passenger side of the car to the driver side of the car, I saw the connected hose going somewhere and saw a mount for it. The mount actually has two holes and only one is taken up by the connected hose, the other hole is towards the rear of the car, so maybe the hose drifted back and not forward. I'll have to see, maybe find it by tracing all the hole from underneath the chasis.

I have the crappy Chilton manual that I barely use, most of the time I search the web that not only gives better explanations and pictures but also people tell you what to look out for. I should get the bentley manual, can't hurt.

Well, thanks for the help, I'll see what I can do (tomorrow possibly) and report back on any progress.

J Strickland wrote:

Reply to
andrey.ivannikov

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