[quasitime]

Update 3/5/2013

-50k miles, plugs replaced @ 48kish
-hpfp replaced
-intermittent long cranks still present (seems to crank strong)
-no misfires
-sometimes idles rough around 600, then rises to 700 or so

What should I start looking at next... injectors? coilpacks?

So right now I'm having an intermittent long crank issue. It happens both on cold and warm starts, but tends to actually be longer on a warm start. For example, I've had a situation where it took 5 long cranks before it would start after being driven for an hour or so. And even then, I thought the car just plain wasn't going to start... so I waited 10 seconds or so before attempting the 5th crank.

Here are the relevant details:

-Pulled A0B4 code which points to the starter.... however the starter seems to crank fine every time. The engine just doesn't always catch.
-50k miles
-Spark plugs replaced at 48k
-hpfp replaced in 2010 at some point
-battery is questionable, but it's been charged up to full with a trickle charger. Voltage seemed low in INPA even though charged to full.
-LPFP seems to prime fine
-Warranty is up... so if I take it to BMW they are going to charge me for diag and I have to take all my mods out. And knowing their track record, they won't identify anything.

Right now I think I'm going to start with the battery. Seems like other things it could be are the starter, hpfp (again), lpfp, lp sensor...

Any other ideas?

Thanks...

[MSPORTWORLD]

Originally Posted by quasitime

So right now I'm having an intermittent long crank issue. It happens both on cold and warm starts, but tends to actually be longer on a warm start. For example, I've had a situation where it took 5 long cranks before it would start after being driven for an hour or so. And even then, I thought the car just plain wasn't going to start... so I waited 10 seconds or so before attempting the 5th crank.

Here are the relevant details:

-Pulled A0B4 code which points to the starter.... however the starter seems to crank fine every time. The engine just doesn't always catch.
-50k miles
-Spark plugs replaced at 48k
-hpfp replaced in 2010 at some point
-battery is questionable, but it's been charged up to full with a trickle charger. Voltage seemed low in INPA even though charged to full.
-LPFP seems to prime fine
-Warranty is up... so if I take it to BMW they are going to charge me for diag and I have to take all my mods out. And knowing their track record, they won't identify anything.

Right now I think I'm going to start with the battery. Seems like other things it could be are the starter, hpfp (again), lpfp, lp sensor...

Any other ideas?

Thanks...

HPFP should still be covered right? Otherwise starting with the battery is probably the best plan of attack. Start with the cheapest possible source for the problem and work your way up.

[CUTigers]

You have no reason to take mods out if you went to BMW, you have no warranty to lose. Granted I would take it to an Indy shop anyways, it's cheaper.

How old is the battery?

[quasitime]

Yeah hpfp warranty is still in effect. My worry is that I'll void that if I take it in with mods on.

But otherwise, it's a breath of fresh air not having to worry about my mods anymore.

The battery was replaced in late 2009 so it's a few years old at least.

[quasitime]

Does anyone know what the battery voltage should read with the car turned on but the engine not running?

Something like 11.7-8?

[techwhiz]

Injectors can cause long starts.
Injectors are still under recall for most cars.

[quasitime]

Hmm. So if I take everything out and go into BMW to have my hpfp & injectors checked out... any idea how much they will charge to look at it if I'm out of warranty?

[ChuckD05]

my dealer doesnt care whats on the car , if he needs warranty work requiring pictures to BMWNA they will tell you and let you pull them... id hate to have it any other way... if no pics or reps are sent they do the work

[quasitime]

Nice. I'm sure every dealer / SA is different though. I'm still wondering how much they charge on a non-warranty vehicle to do the hpfp/injector tests.

[quasitime]

So I have the recalled injectors in my car. I double-checked today when I was replacing some filters.

Car's warranty is up - should I even bother taking my tune out when I take it in... has anyone had experience with this?

[quasitime]

Long cranks, 4 or 5 in a row cold, or hot, before it starts.

I think I'm going to pay the $150 diagnostic and just take it in with tune in. I don't see why they would look in the ECU box if they're just doing the hpfp test.

[quasitime]

Update 3/5/2013

-50k miles, plugs replaced @ 48kish
-hpfp replaced
-intermittent long cranks still present (seems to crank strong)
-no misfires
-sometimes idles rough around 600, then rises to 700 or so

What should I start looking at next... injectors? coilpacks?

[BillionPa]

how long ago was the hpfp replaced?
if it was a while ago it may not be the most recent revision

and yes, injectors next, if they are under recall, they will still be replaced for free even with vehicle out of warranty since they are part of the emissions system

[quasitime]

Originally Posted by BillionPa

how long ago was the hpfp replaced?
if it was a while ago it may not be the most recent revision

and yes, injectors next, if they are under recall, they will still be replaced for free even with vehicle out of warranty since they are part of the emissions system

Well the hpfp was replaced 1 month ago. So hopefully that crosses that off the list.

Hmm injectors. Wouldn't injectors cause misfire issues if they were leaky or defective? Just trying to understand how they could cause start issues and work fine otherwise.

[BillionPa]

they would not all the time, there is another thread regarding rough idle... LOTS of info on bad injectors with no misfires or codes

Other things to check that can cause this behavior in all engines (and some N54 specific):

IAT sensor
Boost pressure sensor
Coolant temp sensor
MAP sensor
Throttle body (electronic, controls idle air flow)
Low pressure sensor (did they replace this with HPFP?)
Intercooler (could be filled with oil blowby)
MAF sensor (clean it with MAF cleaner)
Wastegate position (should be fully closed i think)

Some of the values can be read with INPA, they should be ready with engine "on" but not cranked, and during crank, and after successful engine start, then compared to expected values and behavior



when the spark plugs were replaced was dielectric grease used on the ignition terminals?

[quasitime]

I'm not sure if dielectric grease was used. It was done by an indy shop. I'll have to take a look at that rough idle thread but my idle only stumbles lightly every once in awhile - definitely not bad.

[Jeff@TopGearSolutions]

Don't forget it could be your low pressure pump too...

Do you have a tool that can read BMW codes (i.e. Bavarian Technic Tool), specifically shadow codes? That might throw you a hint.

Your idle being rough could be fuel related and or could be carbon build up in the intake valves, common over 35K miles.

[quasitime]

I have INPA so I can read most of the codes and pressure values. Even the lp sensor reading looks good.

I have a0b4 (starter) but the car cranks pretty hard each and every time. I think it throws that code simply because the car fails to start sometimes even though it is cranking.

Is it possible to "clean" injectors with something like techron? I've been wanting to try something like that forever.

[BillionPa]

I use Amsoil PI, which has the same active ingredient as techron

[Royce_335i]

I think normally the problem with the injectors is that they leak causing excess fuel when starting up, not that they need cleaning.

[Greatdane84]

Quasi can you update us on what happened in the almost 2months this thread was inactive for? You left off talking about going in to the dealer about the injectors and then almost 2 months later you say a month ago your HPFP was replaced. You obviously went to the dealer. Did they replace your injectors? Did you remove the tune?

[quasitime]

Originally Posted by Royce_335i

I think normally the problem with the injectors is that they leak causing excess fuel when starting up, not that they need cleaning.

I was researching this a bit. How would this cause long cranks... fouled plugs? I'm going to take a close look at the injectors and see if there are any that look messy or discolored.