BMW M5 Forum and M6 Forums banner

1 - 11 of 11 Posts

·
Registered
Joined
·
213 Posts
Discussion Starter · #1 ·
So, yesterday I went to the BMWCCA car control clinic, and towards the end of the day, I was running on the skid pad. When i started the skid pad, I had about a 1/4 tank of gas. Counter clockwise was first, and all went well. I did 4 runs of 4 laps each. Then, I did my first 4 lap run clockewise, and got back in line.

I was sitting at idle, and after about 30 secs of idling, my idle started to get rough, and I was sort of think "uh oh" and and about 10 secs later, the idle got really bad, and I tried to put a little gas into it, and the engine just cut out.

I called over some people smarter than I, and then tried to start it. It started just fine, but then died after a couple seconds. At this point, I looked at my gas guage, and it was almsot at a half tank now (so it got higher). Given that this all happened right after the clockwise run, and the fuel pump is on the passenger side, we figured the gas must all be stuck on the drivers side (since the tank has a hump to clear the driveline), starving the pump, and the pressurized lines are what kept it going for as long as it was.

I put in more gas, and was good to go, and I was happy with this explanation. But then I took a look at realoem today, just so i could see waht the tank looks like and what not, mostly out of curiosity.

SKIP HERE IF YOU DON'T WANT TO READ EVERYTHING ABOVE:

What grabbed my attention was part 16116752839 which is called "LEFT SUCKING JET PUMP" which, to me, seems like something which would grab the fuel from the drivers side of the tank. This makes me think I shouldn't have had the problem I had, since it would have pulled fuel from the left even if there was no fuel in the right. Is there something wrong with my fuel delivery system? Or is that part not what it seems to be?
 

·
Registered
Joined
·
1,683 Posts
your thoughts are right..based on what you mention, i agree with you on the left sucktion pump.


first check your cluster for the fuel levels. then you will be sure iff the fuel gets stuck on the drivers side.

but it will be the syphon pump for sure , no douhbt.
 

·
Registered
Joined
·
213 Posts
Discussion Starter · #3 · (Edited)
first check your cluster for the fuel levels. then you will be sure iff the fuel gets stuck on the drivers side.
Well, it went from 1/4 tank to jsut under 1/2 tank during the exercise, and since the sensor is driver side, it seems to make sense.

but it will be the syphon pump for sure , no douhbt.
Sorry if this is a dumb question, but is the syphon pump the "left sucking jet pump" listed on realoem? Are you saying this should be replaced?

Thanks for the help! Appreciated.

EDIT: nvm, using syphon to search, instead of jet pump, I was able to find this thread:
http://www.m5board.com/vbulletin/e39-m5-e52-z8-discussion/138026-m5-runs-out-gas.html
Your posts in that thread are great. Thanks.
 

·
Registered
Joined
·
1,683 Posts
there are no dumb questions my friend,:haha2:

yes , the syphon pump is the left sucking jet pump indeed.


first off all unlock your cluster in the car, and go to test nr6 thats the fuel levels in both tanks.
iff there is more fuel in the left side off the screen then the right , then thats your first clue for a jet pump faillure.
then go too test 14 and look iff you dont see a D7 code..then your 100% sure its the left jet pump.

after that search for a fuel pump diy..there is a good diy available..thats the main fuel pump

for removal off the left jet pump you need to remove the main fuel pump also
iff you look at real oem for the left jet pump you see its like a plastic pipe, well that one goes from the passengers side up too the drivers side through the tanks.

so follow the main fuel pump diy for the one side,then on the other side there is the same hole like the main pump.so the first steps for the main fuelpump are the same for the jet pump..too open up the tanks
open that one ,then you will see the end off the jet pump is clickt in a holder. click it off, and pull the jet pump out from the passengers side through the tanks..(after you removed your main fuel pump offcourse)

take the new one and stick it in again from the passengers side towards the drivers side.the fuel tank looks like 1 tank with 2 compartments with a hole in the middle .stick it through the hole, click the end off the jet pump in the holder on the drivers side. then click the other side in the holder where the main fuelpump is located. and then follow the main fuel pump diy again too close everything up again..



its really not that hard off a job. anybody can do it, aslong as you realise your working with something flammable..

so try too get as mutch fuel out off the car as possible..i replaced mine some time ago with a full tank off gas and it wasn't a joke..i was scared sh*tless i would torch my car up from some static discharge or something..:7:

so just be carefull, and its no big deal.1 hour work
 

·
Registered
Joined
·
213 Posts
Discussion Starter · #5 · (Edited)
Ok, I jsut went out and did test 6 and 14. I took pics of all teh results, but I figure it overkill to actually post them, mostly took the so that i can type out exactly whats written here:
I did test 14 first, and here are the results. I used the left button to cycle through 5 screens of results:
Here they are typed charachter for charachter. Line break means I cycled to next screen:
DIAG: 1 F4 84 000
DIAG: 2 F7 84 000
DIAG: 3 F8 84 000
DIAG: 4 F5 84 000
DIAG: 5 90 84 034

I don't see D7, so it seems the syphon pump is dead. What would D7 mean?
And test 6: (keep in mind i filled a full tank right after i left the event, and only drove home since then)
TNK: 26.8/31.0/57.8L
TNKANZ: 59.1L PHASE1

It seems there is more fuel on the right, which doesn't make sense to me.
I think this is a good time to replace the main fuel pump too, since its the original, and has 108k miles on it.

EDIT: Im going to order parts right now. Is the siphon pump and main fuel pump all I need, or is there something else i should get as well? I figure by the time I get the parts, i should be under a half tank. (hopefully)
 

·
Registered
Joined
·
1,683 Posts
D7 is the code on the cluster that says your jet pump is broken /malfunctioning.

the right side/passengers side fuel tank is a little bigger then the left one, so its normal you got those readings now..
what i have seen on my car was that there was always 20-13L left in the driversside tank, passengers side was empty or lower by then..
drive your car up too 1/2-1/4 off a tank and see again.
you really need to drive it towards empty too see it on the cluster..fuel gets from 1 tank too the other from movement off the car, until it gets too low to slush over.

just drive the car and occasionally look at test 6 once your fuel level gets a little lower (1/2 tank or less).. iff the passengers side has less fuel in there then drivers side its the jet pump.
now that its filled up you cant see it clear..


when you replace the jet pump, and you have some pocket change too replace the main pump also..do it. it will save you time, money in the end.




some off the codes you typed..

F4 CAN Identification missing
F7 CAN Identification missing (DME)
F8 CAN Identification missing (DME)
F5 CAN Identification missing (ASC)
(for some reason the cluster cant connect with the DME/ECU and asc)
dont know mutch about electronics but maybe those came from the 90 code ??????..no idea!!

90 Power supply Term. 15 (you had a low battery voltage a while ago probably ):biggrin:

iff you have a code reader clear the codes on the car,(peak reader, DIS, car soft or any other brand that works on our car)
could be some old codes..clear and check again after some days.
 

·
Registered
Joined
·
1,683 Posts

·
Registered
Joined
·
213 Posts
Discussion Starter · #8 ·
D7 is the code on the cluster that says your jet pump is broken /malfunctioning.


some off the codes you typed..

F4 CAN Identification missing
F7 CAN Identification missing (DME)
F8 CAN Identification missing (DME)
F5 CAN Identification missing (ASC)
(for some reason the cluster cant connect with the DME/ECU and asc)
dont know mutch about electronics but maybe those came from the 90 code ??????..no idea!!

90 Power supply Term. 15 (you had a low battery voltage a while ago probably ):biggrin:

iff you have a code reader clear the codes on the car,(peak reader, DIS, car soft or any other brand that works on our car)
could be some old codes..clear and check again after some days.
Ya, I replaced the battery a couple weeks ago becasue i left he glvoe box open one weekend and it drained the battery... fail. It woudln't hold a charge after that.
Also, I installed the shark injector a few days ago. I don't know if that would cause any codes (love the extra torque down low, by the way)

I've got a peake code reader, so I will go clear the codes now.
 

·
Registered
Joined
·
213 Posts
Discussion Starter · #9 ·
So, im under a half tank now, and all the fuel makes its way to the passenger side. I went around a right turn hard to get fuel into the drivers side tank before parking the car, and then idled still. Over about 5 mins, all the fuel moved to the passengers side, so I assume the siphon pump is actually working. Is there another explanation for the problem I had?
 

·
Super Moderator
Joined
·
4,850 Posts
I don't think you have validated problem yet. If your #7 (nerio's diagram) was dead, you would never reach a 0L left tank reading when under 31L of gas. If your #6 was malfunctioning, you'd get a D7 under test-14, and sloppy gas gauge readings when low on fuel.

I'd guess that as a result of high G clockwise turns, #1 picked up gunk or air and put a hiccup in the fuel delivery. Check/change your fuel filter and put in the back of your head that #1 might be giving up the ghost.
 

·
Registered
Joined
·
213 Posts
Discussion Starter · #11 ·
I'm thinking it might be favorable to just replace the main pump and filter and call it a day. I say this largely because, as you said, the fuel pump is probably on its way out, and I think it would be best if my fuel pump didn't die out in the middle of nowhere. Plus I'm planning to take a long roadtrip in a couple weeks. Would you say this is a good plan? I don't think I need to replace the siphon, because it seems to be working, and even if it does die, its not as likely to leave me stranded.

Thanks for all the help, its greatly appreciated.
 
1 - 11 of 11 Posts
Top