91 850 - Lost fuel to the right side of the V12, which pump?

Which fuel pump works the passenger side 6cyl of the V12 ? I can feel one of the filters and lines working, but I cant tell which side fuel pump it is without tearing the car down first.. I was considering ordering both pumps, but the passenger side pump is like 600 dollars, and the drivers side is less than 200.. That is for the whole fuel pump modules rather than just the replacment pump itself..

Is there a better brand that people are having luck with? And does the same replacement fuel pump part #'s work on both sides? Any help would be appreciated.. I have checked everything over, and I can clearly tell the passenger side is not getting any fuel delivery...

Thanks

I called a company I have dealt with on other pumps for custom builds, and they have a performance replacement pump for the BMW applications.. I have used these pumps in other cars, and they work great, so I will give them a try... Here is a link... 79 dollars each also, and come with everthing for the replacement...

http://highflowfuel.com/i-5210264-hf...1981-1998.html

there is no passenger and driver side. The fuel pump carrier is under the rear passenger seat and is only sold as a complete unit (2 pumps, level sensor). The carrier under the rear driver seat contains the siphon pump (non-electric - it keeps the level even in both halves of the tank), and another level sensor.
You can "feel" the hoses at the carrier to see which one is faulty.

What is the reason for two filters and two feed lines? One filter and feed line, I can feel the fuel running through it, and the other I cant feel any movement of fuel.. So, is there actually two pressure pumps for the motor in that assembly? Is there a place where I can see how this set up works..? My Ferrari Testarossa actually had two pressure feed pumps for the motor, one for each bank.

So, no right and left pump... But there seems to be Bosche/Carter, and other replacement pumps that are made to repair the existing two pump module.. I am under the assumption they are like other replacment pumps out there, you just remove the factory pump from the housing assembly, and replace it with the aftermarket pump... Even General Motors sells replacement pumps as an option, instead of the complete module...

One pump and filter for the left bank and one pump and filter for the right bank.
You can remove the individual pump, but from my experience once one goes, the other is not too far behind. Also, the carrier itself is made of plastic and they do tend to leak at the electrical connector (which CANNOT be fixed, no matter what you use-been there done that).
I would first determine if the reason the other pump doesn't work isn't because of some other problem with the motor.
These cars have what is known as "Limp Home Mode" where it will actually shut down one bank if the computer cannot get it to run like the other bank. This will happen with MAF failure, FPR failure, CPS failure, O2 Sensor failure, etc. If you get the car into Limp Home Mode, the computer will shut off the fuel pump and the ignition to the appropriate bank.

I would check the pumps at the pump carrier electrical connection - apply 12V to each pump. If they both spool up, then you have a whole different issue causing a fuel pump shut down.

Hope that makes some sense....

I got both pumps working, but I cant seem to get the car out mode.. Is there a procedure to do this, I have tried to disconnect the batteries for a few minutes, but that doesnt do a thing.. I am hoping it is in limp mode atleast, because the check engine light is on...

Is there a way to manually read the codes on this car via check engine light flashing... I know alot of the older cars out there you could..

It is known as the Stomp Code.
Go to www.wuffer.net and download the repair manual. There is also a document about the Stomp Codes and what they mean.
If you can't find additional info, try here---> http://forums.bimmerforums.com/forum...splay.php?f=55. There is plenty of info there.

Thanks. I found the code 1222 Which basically say the computer picked up a lean mixture on one side for more than 10 seconds.. The other computer with the 6 stomp is a 2444 which I think interpets to no problem found, because a 1444 is suppose to mean that for the other computer, and I cant find any similar codes listed.

I have power to both fuel pump fuses, but when I pull one of them out, the motor dies immediately, and the other one offers no change.. I guess my fuel pump try today didnt work.. I have other pumps on order and will be here wednsday, and I will just replace both of them this time with matching pumps.. The flow and pressure ratings on the pump I installed today, were the same as the BMW pump, so I figured it would work, guess not..

Lean on bank 1 (passenger side).
The fuse you removed is the one for the pump to bank 2 (7-12, driver side).
Nothing wrong with either of your fuel pumps. Your problem is in Bank 1 (1-6 Passenger side).
What is most likely the culprit (and you can easily check this) is going to be the MAF, or the DK motor.
First I would swap MAF sensors from one side to the other, if the problem jumps sides, then you know it is the MAF.
If there is no change, then move on to the DK motors. Swap left to right and see if the problem jumps sides. If it does, then that is the problem.
MAF might need to be rebuilt, as would the DK motor if that is what is wrong.
Remember, this engine is basically two inline 6's connected at the crank and each side must be synchronized to the other (that is why you have 2 of everything). If the computer can no longer compesate for individual components electronically (by spark timing, fule injection duration, etc. ), it will shut down that side and throw you into limp home mode - which basically shuts down the fuel pump and the spark to the bank that is affected.

You have some trouble-shooting to do - BEFORE you start buying expensive parts...

Wouldnt there be other codes involved also if the MAF or throttle is out..

Swapped them over, and got the same 1222 code.. I can also feel both throttles opening eveningly, and everything seems to be in working order.. The drivers side is working, I can remove the coil wire on the passenger side with no engine change, then remove the drivers instead and it dies immediately..

There is a difference in resonance on the fuel lines, all the injectors are popping electrically, it has fire on both sides, both throttles are working evening, there was no difference in swapping sides. And it is taking way more cranking time to get it started, about double the cranking time, until it feels like it has adequate fuel..

It all happened suddenly yesterday, and I was able to tell that one pump had no pressure.. I pulled the line from the filter while the car was running, and it only emptied the fuel filter with no real pressure.. I did not put a direct replacement BMW pump on it today, it was an experiment to see if a pump with the same volume and pressure rating would work, there may be some other reason why it wont.

So, no change on the firing side of the engine, no change in codes, and both throttle motors are working evening through the rev range... I am hoping it is just the crappy fuel pump.. LOL

have you checked the fuel filters?

Yes.. new filters.. Clean fuel coming out.. And when this situation happend, it was like a switch shut off.. There wasnt a stumbe or sputter before, and everything was just as smooth as can be prior..

OK OK.. I figured it out.... It was a big case of Dumb Ass on my part.. I did lose a fuel pump, so the diagnoses was correct.. What I did was, replace the wrong pump. I replaced a good pump with the new one, and left the locked up pump in its place.. I sat her stewing about it, thought maybe I got the postive and negative mixed up by accident on the connector adaptation, but it good.. So I tested the pump I took out and it spit the fuel that was in it everywhere.. I then tested the factory pump I left in the tank, and it was the one lock up.. ha ha.. A wasted day on Dumb ass...

Thanks for the help, but it is hard to help dumb ass mistakes sometimes.