First breakdown - possbly fuel pump?

[JP 91iS]

So I just took my car out for the first extended road test.  I was planning on getting everything up nice and warm before I drained the oil to check out the oil pan/ pick up bolts.

I got a solid 11 miles outside of town on some twisties when the car bogged down suddenly and then about 10-20 seconds later the engine died.  I coasted to a good stopping point to check things out.

1) Engine cranks over - no start or even a stutter.
2) No blown fuses
3) Pulled back seat and fuel pump cover off - I don't hear any noises coming from it.

I'm going back out there to meet the tow truck so hopefully I can run some tests tonight when I get it home.  Any suggestions on what else to check?

[txleadfoot]

With your fist, pound on the sheetmetal around the fuel pump while cranking.  if it acts like it's going to start then you'll know.  You may not hear any pump buzzing during start up unless you bypass the ignition system altogether and use a standalone power source (in a pinch I once used a 19v cordless drill battery with clamp-on leads).  Do you have a spark tester or an old timing light to verify spark?  Do you have a spare pump to take with you?  Also, take some extra relays and fuses with you.

[Cobra Jet]

The quickest way to tell if the fuel pump is shot - pull the back seat, pop the cover to the pump, and if you have a jump box or way of powering the fuel pump direct - wire a (+) and (-) lead, touch the leads to the pump and if it fires up, it's not dead.

Do the pedal test to extract any stored codes.

I will say, if the cracnk positioning sensor is dead, you may not get an error code....  I went through an ordeal w/ my 318ic a little while back where I too had a non-start issue.   That thread has a TON of diagnostic tests and many responses from others helping out.  I was not getting any error code for my non-start issue - and in the end after testing MULTIPLE sensors, relays, jumping the fuel pump, checking all fuses, etc etc etc...  in the end, it turned out to be my crank positioning sensor...

When the CPS fails, there is no relay back to the DME to fire up the fuel pump - since the CPS is not relaying data back to start the fuel pump, the fuel pump will not prime... and so on and so on.....................

Do the pedal code extraction first - if you get a code, post it up.  If you don't get any code, then jumper the fuel pump direct, if it immediately turns on, it's good... then diagnose from there (check out my previous thread).

Hope that helped ya out some...

[JP 91iS]

The quickest way to tell if the fuel pump is shot - pull the back seat, pop the cover to the pump, and if you have a jump box or way of powering the fuel pump direct - wire a (+) and (-) lead, touch the leads to the pump and if it fires up, it's not dead.

Do the pedal test to extract any stored codes.

I will say, if the cracnk positioning sensor is dead, you may not get an error code....  I went through an ordeal w/ my 318ic a little while back where I too had a non-start issue.   That thread has a TON of diagnostic tests and many responses from others helping out.  I was not getting any error code for my non-start issue - and in the end after testing MULTIPLE sensors, relays, jumping the fuel pump, checking all fuses, etc etc etc...  in the end, it turned out to be my crank positioning sensor...

When the CPS fails, there is no relay back to the DME to fire up the fuel pump - since the CPS is not relaying data back to start the fuel pump, the fuel pump will not prime... and so on and so on.....................

Do the pedal code extraction first - if you get a code, post it up.  If you don't get any code, then jumper the fuel pump direct, if it immediately turns on, it's good... then diagnose from there (check out my previous thread).

Hope that helped ya out some...

Thanks .  Do you remember what you titled the thread?

[Cobra Jet]

why certainly:

http://www.m42club.com/forums/showthread.php?t=5462

[RED IS 91]

why certainly:

http://www.m42club.com/forums/showthread.php?t=5462

I don't know why the admins haven't stickied that thread :confused:

[roundel318]

There have been quite a few related threads regarding idle/stumbling it would be worth having those threads in a centralized place?

[JP 91iS]

Diagnosis: Dead Fuel Pump

I did all the Bentley electrical tests and everything else checked out.  I put power direct to the pump and... nothing.  So at least I found the source of this problem.

I'm kind of glad it happened, as weird as that may sound.  The towing bill sucked, but I got to finally learn about some electrical stuff.  I never really knew how to use a multimeter until now.  I took advantage of this opportunity to buy some new tools so now I have a tackle box stocked with electrical gear, ready for the next gremlin.

I found this relay PDF informational.

EDIT:  Holy shit! These are expensive!  Anybody with good leads on a cheap replacement?

[RED IS 91]

Diagnosis: Dead Fuel Pump

I did all the Bentley electrical tests and everything else checked out.  I put power direct to the pump and... nothing.  So at least I found the source of this problem.

I'm kind of glad it happened, as weird as that may sound.  The towing bill sucked, but I got to finally learn about some electrical stuff.  I never really knew how to use a multimeter until now.  I took advantage of this opportunity to buy some new tools so now I have a tackle box stocked with electrical gear, ready for the next gremlin.

I found this relay PDF informational.

EDIT:  Holy shit! These are expensive!  Anybody with good leads on a cheap replacement?

Don't go cheap !!! You'll be sitting on the side of the road again !

http://www.autohausaz.com/search/product.aspx?sid=u4ces2ufw1jjwsyxhjmn5fum&makeid=800003@BMW&modelid=1011249@318I&year=1991&cid=22@Fuel%20%26%20Air%20System&gid=6256@Fuel%20Pump,%20Electric

[JP 91iS]

Don't go cheap !!! You'll be sitting on the side of the road again !

Yeah, by cheap I meant cost effective.  Or anything better than $250, but still a good brand.

[Jtuner]

Yeah I did the $75 fuel pump from autozone,, I've been running it around a month and it was a pain in the ass to install.. its already started to buzz really loud.. I will be putting a new bosch unit in asap..
If you're short on cash, hit up bavarian auto recycling and see if they have a low mileage one that can get  you by for now Otherwise, patrick at bma quoted me for $232 shipped,, good luck to you!

[Jimmy Lewis]

Look into Walbro's if you want something cost effective that isn't a pos. I have no experience with them, but my buddy Eric is running one. Anyone care to comment on said fuel pumps? Not too sure which model would serve best as a stock replacement but they are certainly cheaper than a stock bosch unit and are very common. Just a thought.

[JP 91iS]

Isn't VDO the OEM manufacturer?

But I do keep reading that people are using the Walbro pumps.  Anyone know a good source for a new Walbro pump?  I found this website: http://www.walbrofuelpumps.com, but they don't have a kit listed for 318is.  I sent them an email so I'll see what they say about it.

[JP 91iS]

EDIT:  I decided to move this post to a new thread, here