M54 Warm Start Long Crank - Leaky Fuel Injector?

[rawfuls]

So, I actually have an E85 '03 Z4, but has the M54.
I'm posting here because the E46 is way more poppin' than the E85

Just picked it up, has about 109k miles on it.
Recently, been having sparse issues with warm starts, very once in awhile (maybe once a week, if that), on a warm start (at least an hour or so after a drive), it will have a long crank.
Occasionally, will turn over after a long crank, or a guaranteed reliable second turnover right away.

Some research tells me this is fairly indicative of a leaky fuel injector, and to find the leaky injector by driving, waiting an hour, then pulling plugs and look for the plug that smells the most of gas.

I'm considering the following:
1. Drive on it (since it's not frequent), and replace all 6 injectors when money allows.
2. Replace the 1 or 2 leaky injectors after inspecting the plugs
3. Replace all 6 o-rings (special tool needed? top o-ring, bottom o-ring, pintle seat, filter, etc?)
4. Pull all 6 injectors, send them off to someone to have them rebuilt (recommendations?)
5. Pull all 6 injectors, and buy rebuild kits, and rebuild them myself (DIY?)

I'm not quite sure if rebuilding them will be the answer, as the injectors aren't likely​ clogged, but leaky- does rebuilding them resolve this?

[MIKYZZ4]

First off, perform a diagnostic scan, preferably with a BMW specific scan tool/software.
Take note of codes/errors displayed, then clear all codes.
Complete a short drive cycle(or until CEL illuminates,if applicable).
Perform a new scan,
then post back with all results displayed.

[MIKYZZ4]

If scan results indicate an improvement may be made, by cleaning the injectors,
then I recommend RC fuel injector cleaning here:http://www.rcfuelinjection.com/

[MIKYZZ4]

If plugs are fouled, gaps not in spec:https://www.fcpeuro.com/products/aud...g-ngk-bkr6equp

[rawfuls]

Scans were done this past weekend- no codes or faults.

[MarcoZandrini]

The next step is to attach a fuel pressure gauge to the test valve on the fuel rail. Item #2 in the link is the test valve cap.

http://www.realoem.com/bmw/enUS/show...diagId=13_0900

What you’re looking for is the rate at which the fuel pressure decreases.

What tool did you use to scan the engine computer?

[randy72877]

Intermittent cam sensor can cause it also. My 330i would occasionally have a long crank and then a noticeable loss of low end torque which would continue until the car is restarted. I never checked for codes until the engine light came on one time but I'm sure it stored one though. When I read codes there was a cam sensor code. Don't remember which one but after replacing a cam sensor it never did it again. Check for codes if you have not already. Even if your engine light is off.

Sent from my SAMSUNG-SM-G870A using Tapatalk

[rawfuls]

The next step is to attach a fuel pressure gauge to the test valve on the fuel rail. Item #2 in the link is the test valve cap.

http://www.realoem.com/bmw/enUS/show...diagId=13_0900

What you’re looking for is the rate at which the fuel pressure decreases.

What tool did you use to scan the engine computer?

What I'm concerned with is if it's intermittent, the injector may not *always* be leaking, which would make me run into loops with the fuel pressure gauge, I would believe.
I had an indy shop scan the codes with their Snap-On computer.
I have access to an K+DCAN cable & a few BMW Diagnostic Tools, any recommendations where to start with BMW software?


Reached out to MrInjector, who states his service would not service leaky injectors, however InjectorRX says they are able to service and leak-test all injectors, at about $18/ea injector.
FYI: no CEL codes since my ownership since April 2nd.

[randy72877]

Leaking fuel pressure regulator (part of filter) could cause flooding also. It would leak fuel into the engine through the F connector in the intake boot.

Sent from my SAMSUNG-SM-G870A using Tapatalk

[legoman67]

First off, perform a diagnostic scan, preferably with a BMW specific scan tool/software.
Take note of codes/errors displayed, then clear all codes.
Complete a short drive cycle(or until CEL illuminates,if applicable).
Perform a new scan,
then post back with all results displayed.

scans rarely ever help with fuel related issues. These cars dont monitor their fuel system.

[rawfuls]

Leaking fuel pressure regulator (part of filter) could cause flooding also. It would leak fuel into the engine through the F connector in the intake boot.

Sent from my SAMSUNG-SM-G870A using Tapatalk

This sounds like if it were leaking at this point, it would be a little more consistent, and a little more severe, and happen in more times than just a warm start.
The fact that the warm start happens intermittently makes me think it would be the injector.

scans rarely ever help with fuel related issues. These cars dont monitor their fuel system.

That's what I was thinking, thank you for confirming.
Any ideas on the issue?

[MIKYZZ4]

scans rarely ever help with fuel related issues. These cars dont monitor their fuel system.

Exactly, which I why I was seeking a confirmation in another direction.

[MIKYZZ4]

And a more thorough BMW scan,
besides generic OBD2 scantool codes.

[rawfuls]

And a more thorough BMW scan,
besides generic OBD2 scantool codes.

Sure, using what tool?

[MIKYZZ4]

Well then, here are some options,
concerning diagnostic tools,

For a good BMW scan tool, I feel you have 3 options:

• Foxwell nt520:http://www.foxwelltool.com/search/?q=NT520
• Carly for BMW:http://www.mycarly.com/product/bmw-app/
• INPA software for BMW: Do a search on bimmerforums
  
  I recommended them in no specific order,
  as selection is based more on preference.
  
  INPA is an excellent diagnostic tool,
  but is a proprietary BMW factory tool.
  So all available copies are technically bootleg versions.
  This requires a copy of the INPA software downloaded into a laptop computer,
  along with the correct cables for your particular model of BMW.
  I recommend this only for computer geeks, or the mostly computer savvy among us.
  
  For an affordable standalone unit, Foxwell nt510(nt520 Updated version) is the preferred unit, along with required cables.
  It can scan for BMW codes, among other things, as it can communicate with all BMW modules.
  
  Carly for BMW is an APP,
  and as such, requires a smartphone,
  along with a connection to the OBD2 port in your vehicle,
  supplied either by cable or wireless connection via Bluetooth dongle

Update: Now the full version is $74/year on a recurring subscription

[rawfuls]

INPA came back with no issues last weekend when I was also coding.

[MIKYZZ4]

Great, seems everything is up to minimum spec.
Since no obvious problems exist, let's perform some maintenance.

To increase ignition performance, and since age of plugs is unknown,
replace with NGK sparkplugs:https://www.fcpeuro.com/products/aud...g-ngk-bkr6equp

Check condition of airbox:remove and replace air intake filter,
clean MAF & IACV:https://www.walmart.com/ip/CRC-MAF-T...&wl13=&veh=sem

Test fuel pressure at fuel rail: Schrader valve-51psi

Since fuel-filter is integral with fuel-pump,
replace only if fuel pressure not up to spec or erratic.

send injectors out for refurbish:http://www.rcfuelinjection.com/Store...ector-cleaning

And finally, if you care to remove upper engine/combustion deposits,
semi-instructional video:https://www.youtube.com/watch?v=_Vo4fm0JDPY

[rawfuls]

Pulled the plugs, couldn't smell gas on any of them, will be doing a pressure test now.
Found some oil on the threads of the plugs, looks like a valve cover gasket is a next project.
So far, only oil found on the threads, not on any of the tips of the plugs.

Attaching pictures, plugs look to be in OK condition, don't seem to have BMW logo on them, so they were replaced before.
The coil pack boots have a weird heat stripe to them- this normal?


IMG_2288.jpgIMG_2287.jpgIMG_2286.jpgIMG_2285.jpgIMG_2284.jpg

[MIKYZZ4]

As you describe,plugs look to be in OK condition,
but I can assure you, not in pristine condition.
Observe a sparkplug condition chart via Google to confirm.
Is there an abnormal amount of oil consumption?,
because that's what I take out of the plug photos.
As you have observed,they are not original,
but original ones were installed 109K miles ago!

From your photos, replace those plugs!
Try that, then post back.

Try all my recommendations,
you will surely notice a difference!