very long cranking before engine starts

Couple months ago my 99 E39 (528i) would not start. My friend/mechanic
comcluded the problem to be either the fuel pump or the fuel pressure
regulator. Being these components are oringal and nearly 16 years old, I
decided to replace both, plus a new fuel filter.

After the new fuel pump, fuel pressure regualator and fuel filter were
replaced it takes an extremely long time to start the engine when you turn
the key. It cranks for maybe 7 seconds or more. It always starts, and once
it starts runs and idles fine.

Once in a while it will start up like it should, but most of the time takes
way too long.

Any suggestions?

"Yea Right" > wrote in message
31...
> Couple months ago my 99 E39 (528i) would not start. My friend/mechanic
> comcluded the problem to be either the fuel pump or the fuel pressure
> regulator. Being these components are oringal and nearly 16 years old, I
> decided to replace both, plus a new fuel filter.
>
> After the new fuel pump, fuel pressure regualator and fuel filter were
> replaced it takes an extremely long time to start the engine when you turn
> the key. It cranks for maybe 7 seconds or more. It always starts, and once
> it starts runs and idles fine.
>
> Once in a while it will start up like it should, but most of the time
> takes
> way too long.
>
> Any suggestions?
>

Try the following: -

Switch on the ignition and wait several seconds, then try and start.

My guess is that you have a problem I had on an old 1983 E23 once it reached
about ten - namely the fuel was running back down to the tank, it therefore
took a few seconds for the pump to pump it back up (you could hear it)
before the engine would start. There may be a valve(s) somewhere in the
injection system that should stop this.

Yea Right > wrote:
>Couple months ago my 99 E39 (528i) would not start. My friend/mechanic
>comcluded the problem to be either the fuel pump or the fuel pressure
>regulator. Being these components are oringal and nearly 16 years old, I
>decided to replace both, plus a new fuel filter.
>
>After the new fuel pump, fuel pressure regualator and fuel filter were
>replaced it takes an extremely long time to start the engine when you turn
>the key. It cranks for maybe 7 seconds or more. It always starts, and once
>it starts runs and idles fine.
>
>Once in a while it will start up like it should, but most of the time takes
>way too long.
>
>Any suggestions?

Try it with the gas cap open. Does that help? If so, you have a venting
issue.

What does the fuel pressure (as measured at the rail) read before and after
it starts up? How long does it take to drop back down after you shut the
engine off?

The thing about these is that because there is feedback control on the fuel
mixture, the fuel pressure can be _way_ too low and the car will run just
fine until you push it hard.

When you replaced the pump did you also replace the backflow valve? On some
models it's built into the pump but on some it's external.

It also would not hurt to make sure the pump is turning on properly. While
you're under there, attach a light and see. That's unlikely to be an issue
but it's easy enough to check while you have it up.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

I tried the previous responder's suggestion. I turned the key to the on
position and waited 5 seconds and then it starts instantly like it should!
I've consistantly did this a dozen times.

Now about that valve you are talking about. Is this something that can be
adjusted? I know it wasn't replaced unless it comes with the new fuel pump.






>
> Try it with the gas cap open. Does that help? If so, you have a
> venting issue.
>
> What does the fuel pressure (as measured at the rail) read before and
> after it starts up? How long does it take to drop back down after you
> shut the engine off?
>
> The thing about these is that because there is feedback control on the
> fuel mixture, the fuel pressure can be _way_ too low and the car will
> run just fine until you push it hard.
>
> When you replaced the pump did you also replace the backflow valve?
> On some models it's built into the pump but on some it's external.
>
> It also would not hurt to make sure the pump is turning on properly.
> While you're under there, attach a light and see. That's unlikely to
> be an issue but it's easy enough to check while you have it up.
> --scott

"Yea Right" > wrote in message
31...
>I tried the previous responder's suggestion. I turned the key to the on
> position and waited 5 seconds and then it starts instantly like it should!
> I've consistantly did this a dozen times.

Diagnosis I think!

>
> Now about that valve you are talking about. Is this something that can be
> adjusted? I know it wasn't replaced unless it comes with the new fuel
> pump.
>

Dunno on this model, but you could always try one inline as near the engine
as practicable.

>
>
>
>
>
>>
>> Try it with the gas cap open. Does that help? If so, you have a
>> venting issue.

Another possibility, but unless the seal is perfect, usually only a problem
restarting after a long run.

Amusingly some engines misfire if the oil filler cap is left off or not
fully tightened (something to do with scavenging the fumes from the
crank-case and breaking the vacuum, but this is beyond my ken).

>>
>> What does the fuel pressure (as measured at the rail) read before and
>> after it starts up? How long does it take to drop back down after you
>> shut the engine off?
>>
>> The thing about these is that because there is feedback control on the
>> fuel mixture, the fuel pressure can be _way_ too low and the car will
>> run just fine until you push it hard.
>>
>> When you replaced the pump did you also replace the backflow valve?
>> On some models it's built into the pump but on some it's external.
>>
>> It also would not hurt to make sure the pump is turning on properly.
>> While you're under there, attach a light and see. That's unlikely to
>> be an issue but it's easy enough to check while you have it up.
>> --scott
>

Yea Right > wrote:
>
>Now about that valve you are talking about. Is this something that can be
>adjusted? I know it wasn't replaced unless it comes with the new fuel pump.

Depending on the model, it may or may not come with a new fuel pump. Check
the service manual.

Where did the replacement pump come from? Did you get a full kit from Bavarian
or did you get the cheapest possible rebuild from AutoZone?
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

On Thu, 7 Aug 2014 14:07:30 +0100, "R. Mark Clayton"
> wrote:

>"Yea Right" > wrote in message
. 131...

>> Now about that valve you are talking about. Is this something that can be
>> adjusted? I know it wasn't replaced unless it comes with the new fuel
>> pump.
>>
>Dunno on this model, but you could always try one inline as near the engine
>as practicable.

I think it's a far better idea to find and fix whatever check valve
that BMW put in there. And if you *did* decide to put an extra one in
for some reason, then it should be as near to the pump as possible,
not the engine. Oh, and make sure that the 'check' action is facing in
the right direction, too ...