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Discussion Starter · #1 ·
Hello all.

Have had my bimmer for about 5 months now and have never had a problem with it outside of a minor bit of intermittent squealing from the new belt I had put on (possibly loose? and doesn't happen all the time).

Was broke last week and had to drive her to work and ended up with 6 miles on the range display when I made it back home. Didn't get paid for an additional 5 days so she sat in the driveway until then. Went to crank her today and she wouldn't crank (only tried twice) so I ran to the store and grabbed some premium and took her back up to 5 gallons in the tank.

Now, she will crank right up but is idling rough (with a low rumble) and almost tries to choke down while still in park. If I back up and drive, while I am still driving at idle speeds it's acting very sluggish and tries to choke down until I put my foot on the gas a bit at which time it straightens right out.

If I drive down the road a bit, after hitting approximately 30mph, it starts driving and riding like a top again. (doesn't choke down at stops, idles normally, no problems whatsoever). When I pull back up in the driveway and put her in park, she continues to idle perfectly. However, when I cut her off and fire her back up, the problem starts right back up again until I drive a few hundred feet.


This is the only time I have run her under 30 miles on the range calc and I always run premium gasoline.

Any ideas as to what my problem is or possible fixes?

Thanks in advance,
Jasn

Also, the bimmer has 177k miles on her.

Idle problem is only happening upon cranking. Once driven for a minute, the problem stops until I turn the car off and starts again upon cranking (even if I immediately restart).

When the idle problem is happening, the muffler is making a sputtering sound and the card is rumbling/shaking noticeably.


UPDATE: Went out this morning after she sat all night and she would try to crank but I had to put a small but steady flow of gas to keep her cranked til she warmed up. Still stumbling hard while in idle and I'm certain she would probably run fine once I got her warmed up and on the highway but I don't want to drive her anywhere until I get some opinions for fear of causing any more damage.


Any help or suggestions you guys can give me is very much appreciated. Also, feel free to ask any questions you may have in regards to more information I may need to supply. Thanks.


Also, I'm new to the forum.
 

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I suspect you might have overheated the fuel pump (gas keeps it cool, that's why it's not recommended to run real low on gas) and damaged it. I'd start by having someone check the fuel pressure/volume ... it really does sound like it's choking due to a lack of fuel.
 

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Discussion Starter · #3 ·
Thank you.

That's pretty much along the lines I was thinking but, after reading several threads, I saw suggestions of similar problems ranging from o2 sensor to gunk in the fuel line so I wasn't really sure.

Should I be fairly safe to drive it to get it to the shop so they can take a look at her?
 

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Discussion Starter · #4 ·
UPDATE:

Car is still running great once I get it on the highway. Idles perfectly at stop signs and once I pull it back in the driveway.

Made a special point to turn the ignition over several times to position 2 and it definitely sounds like the fuel pump is priming (assuming the fuel pump is under the rear seat).

Any other avenues I should check out before taking her to the mechanic?


All suggestions and help are very much appreciated.


Also, if it is a bad fuel pump, will the car continue to run fine and simply fail to crank when/if the pump actually goes out?

Sorry, not a mechanic AT ALL haha. I like to get some ideas before going to the mechanic so I know sort of where I stand on the options.
 

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It will still crank if it goes (if it is the pump); it just wont ever start.

Gunk in the lines could be possible, but the chances are extremely slim: the pump has a strainer on it, and then you have the filter ... I really doubt something got through between the two.

As for the O2 sensor: until the car is warmed up, it's in open loop: meaning it does not take the reading from the o2 sensor, so I'd pretty much rule that out since it sputters from the get go.
 

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Discussion Starter · #6 ·
It will still crank if it goes (if it is the pump); it just wont ever start.

Gunk in the lines could be possible, but the chances are extremely slim: the pump has a strainer on it, and then you have the filter ... I really doubt something got through between the two.

As for the O2 sensor: until the car is warmed up, it's in open loop: meaning it does not take the reading from the o2 sensor, so I'd pretty much rule that out since it sputters from the get go.

Cool. Thanks.

As long as it's still starting, should I be pretty safe to drive it to the mechanic? I would assume that if the fuel pump completely fails, it will not really be noticeable until the car is turned off and I am trying to start her up again? Would that be correct? Or do I run a risk of a breakdown while in traffic?

As I said, it's starting now and runs great on the road. The problem comes immediately after start up in the form of sputter/hesitation/shaking/weak idle.

Also, will a SES light diagnostic check return code for a bad fuel pump?


Thanks.
 

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I'd drive it; if it does die, it means the engine stops, but hey, you gotta take risks sometimes. :D

I mean it could be something else, but given it started after you drove it with almost no gas, I'm suspecting something to do with the pump ... your mechanic will know better.

As for the codes: I know there's a code for something about fuel pump control and the injectors; if you have a light (and even if you dont you might have stored codes), have it scanned and see what you got.
 

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I'd drive it; if it does die, it means the engine stops, but hey, you gotta take risks sometimes. :D

I mean it could be something else, but given it started after you drove it with almost no gas, I'm suspecting something to do with the pump ... your mechanic will know better.

As for the codes: I know there's a code for something about fuel pump control and the injectors; if you have a light (and even if you dont you might have stored codes), have it scanned and see what you got.
I had the Same thing and the Mechanic Knew straight away at the Back of the carb there is a fuel flow valve they wear out at around 100kms 60kmiles
Replace it and it will run fine ( not an easy job , need a Tech driver to remove the small studs )
 

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Discussion Starter · #9 ·
Update:

Took her to Advance Auto Parts......returned 13 codes.

10 of which were related to idle control valve.

1 of which was air flow sensor (o2 sensor??? help with this one)

2 were random cylinder misfires (tune up?)


I'm going to try to pull the ICV this weekend and see if I can clean it.

Returned no codes on the fuel pump.


Sound like my best course of action?

Clean ICV, tune up, replace plugs.


Thanks for the help guys
 

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Update:

Took her to Advance Auto Parts......returned 13 codes.

10 of which were related to idle control valve.

1 of which was air flow sensor (o2 sensor??? help with this one)

2 were random cylinder misfires (tune up?)


I'm going to try to pull the ICV this weekend and see if I can clean it.

Returned no codes on the fuel pump.


Sound like my best course of action?

Clean ICV, tune up, replace plugs.


Thanks for the help guys
Not the same thing; the MAF is on the intake pipe .. looks something like this: Imageshack - intakeelbowandmaf2.jpg

Take it out and clean it too: just make sure you buy MAF cleaner (and yes, its a different product to the carb cleaners and what not).

I guess that's a start: clean both of those, change the plugs and see if it changes; like I said it could be stuff unrelated to the fuel delivery, but that was my first guess given when it started.

Good luck, keep us posted.
 

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Discussion Starter · #11 ·
Indeed I will Torque.

Thanks for all the help thusfar guys.

I'll probably have to wait until the weekend to get into it. I know I saw a great guide for how to remove and clean the ICV on here somewhere, I'll have to pull it up again.


Thanks for everything,
Jasn
 
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