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hey guys and gals,


haven't post in awhile but something has come up with the m5 that has me stumped. the car is starting, but not running i determined that it is a fuel issue, so i went over all the common stuff new fuel pump, new fuel filter, fuses,new fuel pump relay,new senors. then i was told by my shop that it might be the secondary fuel pump that they said is somewhere in the engine bay that is hard to get to. but i seem to not find any images of it or how much it costs.

is there a secondary fuel pump? i searched the forums and cant find anything any help would be appreciated
 

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No. There is no secondary fuel pump.
 

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I'd also consider looking for another shop. That is a kind a red flag for a shop competence. Not everybody should be working on cars as complex as ours are.
 

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I'd also consider looking for another shop. That is a kind a red flag for a shop competence. Not everybody should be working on cars as complex as ours are.
Agreed. Maybe the OP's car is low on blinker fluid??? ;)

The only other thing that comes to mind is the siphon pump which transfers fuel from the left side of the fuel tank to the right side, which feeds the engine. But if the OP has more than about 1/2 tank of fuel, that should not be an issue either.

Regards,
Jerry
 

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I am going to skip the humor of the secondary fuel pump, but I really want to make a joke. So the car starts but fails to run, why do you think it is fuel? Have you unplugged the MAFs electrically? It still may not wan to run because of adaptions but play with the gas and see if you can keep it running for a bit to change adaptions. If it will stay running let it run longer. Basically you want to see if the car runs differently without the air volume signal. Oftem when that signal is wrong it appears that you have a fuel issue but really it is just bad MAFs.
 

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Try to start the car a couple of times (of 'normal' length in time), in succession and then pull one of the spark plugs: If it's still dry then the engine is not getting fuel. Then do the MAF-disconnected test as already suggested. I would also verify that the fuel pump is running: Pull the rear seat and remove the cover (on passenger side) that is attached with 3 Phillips screws. Let someone else start the car and check if you can feel (fingertips) or hear (pencil on the circular cover, your ear on the other end of the pencil) any vibration of the fuel pump on the black circular cover. No vibration to be felt/heard could mean a dead fuel pump, or the fuel pump relay is not properly grounded by the engine control unit (DME), which is a problem for your 'matured' indie. A dead fuel pump can sometimes be checked pretty easy: Tapping with a rubber mallet on the cover, sometimes temporary kicks some life into the fuel pump again, but if it does, it means the brushes of the fuel pump are worn. If the spark plug is wet from fuel, than perhaps sparks are absent. Then it's time for the spark plug test.

Spark plug-test
Connect the ignition coil to the wiring again, stick the removed spark plug in the ignition coil and put it on the cylinder head (a bit away from the threaded hole, to prevent the engine from fire-spitting* ...!), so that the outer thread of the spark plug touches the metal of the head. Let someone else start the car, while you check for sparks.

ICV (Idle Control Valve)-test
During the starting attempts, simply play with the gas pedal. If the car now starts, then it indeed is the ICV that is not opening enough (due to carbon deposits) for idle air flow to pass. If not, the causes above are more probable.

*) With a 9th spark plug lying around, you can install the pulled spark plug again and do the spark test with the 9th spark plug. You'll certainly see no fire-spitting then ...:wink
 

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No. There is no secondary fuel pump.
While I agree about the lack of knowledge of the S62 at this shop....keep in mind that many of the later models have a secondary (cam driven) high pressure fuel pump in the engine bay just before the fuel rails. Not making excuses for them, but if they weren't listening that closely, it would be an understandable assumption to make.
 

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...keep in mind that many of the later models have a secondary (cam driven) high pressure fuel pump in the engine bay just before the fuel rails. Not making excuses for them, but if they weren't listening that closely, it would be an understandable assumption to make.
No high pressure fuel pump on the engine/ in the engine bay of the S62B50. It is only present on diesel engines like:
E39 type ------------ Engine type -- HP-fuel pump BMW-no.
E39 520d ----------- M47 ---------- 13517787532
E39 525td or 525tds M51 ---------- 13512244966
E39 525d or 530d -- M57 ---------- 13517787632

The S62B50 engine however does have several other pumps in the engine bay. Maybe you meant one of these:
Lubrication system oil pump
Lubrication system compressor
Air pump for vacuum control
Emission control air pump
 

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? Vacuum pump?
You are justifiably surprised seeing an 'air pump for vacuum control' in my list. Didn't do a detailed check on the Realoem 'list', until now.
At Realoem plot (Engine > Air pump for vacuum control, see the link below), you can see that only the electrical (PWM) control valve 11747810831 plus some attached hoses are highlighted. That valve is hardly to be called a 'pump' ...
https://www.realoem.com/bmw/enUS/showparts?id=DE93-USA-04-2003-E39-BMW-M5&diagId=11_2671

Line #4 in the above plot is attached to one of the carburetor housings, the provider of the vacuum. No need for a vacuum pump on the S62B50 indeed.
Line #9 is attached to the shut-off valve (#8, 11721433713) of the secondary air pump, I guess? Not a pump either.
 

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No high pressure fuel pump on the engine/ in the engine bay of the S62B50. It is only present on diesel engines like:
E39 type ------------ Engine type -- HP-fuel pump BMW-no.
E39 520d ----------- M47 ---------- 13517787532
E39 525td or 525tds M51 ---------- 13512244966
E39 525d or 530d -- M57 ---------- 13517787632

The S62B50 engine however does have several other pumps in the engine bay. Maybe you meant one of these:
Lubrication system oil pump
Lubrication system compressor
Air pump for vacuum control
Emission control air pump
Semantics. I did not mean later model E39, and after rereading my post, I see the confusion. I meant later model BMWs. I am specifically talking about the N54 and S55 engines. My point being that the E39 is becoming old enough that many shops don't see them nearly as often as the F series, so that an assumption is somewhat understandable. That was my only point
 
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