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E39 (1997 - 2003)
The BMW 5-Series (E39 chassis) was introduced in the United States as a 1997 model year car and lasted until the 2004 when the E60 chassis was released. The United States saw several variations including the 525i, 528i, 530i and 540i. -- View the E39 Wiki

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  #51  
Old 02-25-2010, 08:03 AM
Garrison5 Garrison5 is offline
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I haven't read every post so if I'm repeating this then I apologize.

I had a similar situation a few years ago with my 528i in cylinder 3. Same code, but for this cylinder. My approach was:

1) Confirm there is not oil leaking into the area around the spark plug. I had replaced the valve cover gasket shortly before this so that wasn't it.

2) Is the spark plug bad? I swapped the plug with another, but the issue remained in cylinder 3.

3) Is the coil bad? I swapped the coil and it moved the error code to the new cylinder.

Replaced the coil and the issue went away.

These are some simple, easy steps to take that won't cost anything and can help diagnose the problem.

I also read that the computer will shut off the fuel supply to a non-firing cylinder.

Hope this helps.
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  #52  
Old 02-25-2010, 08:06 AM
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Quote:
Originally Posted by Josh P. View Post
seems like it's being over-thunk at this point... you'll be even more frustrated if it's a simple fix.
I'm not looking for the fix. I feel it will help me and MANY others more for us to come up with a believable diagnosis procedure. Lord knows, I've read dozens of posts where the OP replaces this part or that part and, lo and behold, the problem "goes away".

By now, after reading all the posts and seeing the various solutions (some of which are good things to do anyway, e.g., Vanos, air filter, coils, plugs, boots, etc.) ... the one thing I do know is we need a methodical DIAGNOSIS procedure.

To that end, swapping the coils and/or plugs is certainly an early step but I'm still in the learning phase only two days into this problem.

Quote:
Originally Posted by Fudman View Post
Have you started your debugging sequence yet
I'm still in the information-gathering stage (which takes me longer than most as I try to understand that which you guys seem to inherently already understand).

I did PROPOSE a debugging sequence though (see post #35 above).

Quote:
Originally Posted by poolman View Post
What controls the spark---valve timing --what controls valve timing--VANOS seals--- [hence] the signal to the cam position sensors ...
Please correct me if I'm wrong, but, doesn't the crankshaft position control fundamental spark timing (tempered perhaps by a vacuum advance under load and a retarded timing under knock situations)?

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Last edited by bluebee; 03-07-2010 at 07:35 AM.
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  #53  
Old 02-25-2010, 08:57 AM
poolman poolman is offline
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Bluebee--the quick and easy way to check this all out--just as Garrison5 stated--along with otuers--swap out the coils to another cylinder and see if the problem moves to another cylinder--if it does than the coil is bad.
If the problem stays with the same cylinder--swap the plugs out with another cylinder and see if the problem moves again--you wnot be throwing money at the problem that way--until you can find what the problem is.
Garrison 5 by the way is one of the few that did the Vanos seal replacement before I--I read his write up on makeing the change with great interest and was one of the resaons that I made the jump.
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  #54  
Old 02-25-2010, 09:52 AM
Garrison5 Garrison5 is offline
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Poolman, thanks for the props and all the good info you've shared on this site.

I do like what Bluebee is trying to do: Create a methodology for diagnosing problems we have with our beloved e39s.

Could turn into a DIY sticky that brings information from the many posts over the years into a sequential problems solving sequence.

Bluebee, keep going down the path you are on. I think we could all benefit from it.
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  #55  
Old 02-25-2010, 04:35 PM
poolman poolman is offline
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Yes Bluebee--the crank sensor really controls spark--I should have noted that--the cam timing is controled by Vanos--if the cylinders do not get the right amount of charge or expell enough burnt gasses--then the mixture
will be off--and misfire or uneven burn will occure--
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  #56  
Old 02-25-2010, 06:25 PM
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lild lild is offline
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here's the thing i see, you have a misfire, and fuel cut off. what caused the misfire to occur?
1--bad fuel
2==trash or gunk in fuel
3---oil leaking onto spark plug due to bad spark plug valve cover seals
4---head gasket leak, or cracked block, wetting the spark plug
5---fouled out, broke tip, or worn plugs
6==coil pack, or coil pack boot going bad, or is bad
7---bad 02's, pre, or post or all 4
8---bad maf
9---leaking or bad, pour spraying injector
10---crack ring
11---cps==cam shaft sensor
12==cps----crankshaft, but won't cause misfire.
13---bad ground wires.
14--- bad fuse or relay
15---bad wireing
16--- very, very rare===dme, or ecu has gone bad.
17--intake manifold gasket leak
18--ccv--aka pcv
19--icv--idle control valve
20--tps==throttle position sensor

to figure out exactly why you had the misfire, you need a much better scan tool than the basic one, to find out the exact source.
as to why the fuel cut off, like i said, it's neccerssary to keep greater damage from happeing, but to take it more in. when the cylinder doesn't fire and you drive around, the fuel is cut off.
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  #57  
Old 02-25-2010, 06:36 PM
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i just read through some post not all. but i hope your not under the impression that the misfire was cause by no fuel being delivered.
the misfire happen becuse of no spark, no spark then the computer turns off the fuel. not the other way around. unless you have a bad injector.
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  #58  
Old 02-25-2010, 07:57 PM
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Quote:
Originally Posted by lild View Post
what caused the misfire to occur?
We're doing true debugging. Groundbreaking some might say. So this isn't going to be easy.

Let's be blunt. We're not interested (in this thread) in solving the problem; to solve the problem, you just turn the ignition off and back on again. Presto! Problem solved ('till next time). Or, you replace & clean everything in sight that could cause a misfire (coils, plugs, boots, VANOS, MAF, CPS, VCG, ICV, CCV (aks PCV), VANOS, 02 sensors, TPS, DME, etc.). There's nothing wrong with that - but it's not a reasoned debugging sequence given we know two very important things about this problem which has affected many people (and will continue to affect people - hence it's worth exploring).

ONE: It goes away on the next ignition restart ... and ...
TWO: It affects only a single cylinder misfire (albeit a misfire bad enough to cause a subsequent fuel cutoff, at least until the ignition is cycled).

The first big problem with most items on that otherwise excellent list is that the misfire goes away, by all accounts, in the very next ignition cycle (even if that ignition cycle is a mere 30 seconds away) ... and that it does not return in quite some time (indeterminate as yet).

While anything can be intermittent, I doubt items such as "worn plugs" would reliably reset themselves upon the very next ignition cycle.


The second big problem affecting that otherwise excellent list is that it has to affect just a single cylinder (in this case, the #4 cylinder).

Again, anything can happen, but, I would think items such as "bad fuel" are highly unlikely to affect a single cylinder (IMHO).

So we really need to narrow down the culprit to something specific to a single cylinder that is always reset upon the next ignition cycle.

If we follow this tack - which of the 20 items in that list satisfy both requirements?

Last edited by bluebee; 03-01-2010 at 09:33 PM.
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  #59  
Old 02-25-2010, 08:03 PM
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Quote:
Originally Posted by lild View Post
the computer turns off the fuel. not the other way around. unless you have a bad injector.
You astutely brought up two unknowns I alluded to:

1. How do we know that the misfire occurred first, and the fuel cutoff occurred second?

Why can't it be the fuel was cut off (for whatever reason), thereby causing a misfire when the spark jumped the gap?

2. If we had a bad fuel injector, would that not affect ALL the cylinders (and not just a single cylinder)?

Don't all the injectors feed into the intake manifold at the same time?
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  #60  
Old 02-25-2010, 08:24 PM
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Quote:
Originally Posted by poolman View Post
Yes Bluebee--the crank sensor really controls spark--I should have noted that--the cam timing is controled by Vanos--if the cylinders do not get the right amount of charge or expell enough burnt gasses--then the mixture
will be off--and misfire or uneven burn will occure--
I'm trying to understand the VANOS argument.

Is this the VANOS argument (in detail sufficient to understand how it would cause a single cylinder to misfire yet reset upon the next ignition cycle)?

Let's assume the VANOS seals don't seal well (which has been well documented for the E39) ... therefore cam timing is off ...

Q: What happens if cam timing causes the intake valve to open too soon?
A: If the intake valve opens on the tail end of the exhaust stroke, I guess exhaust gases go backward into the intake manifold momentarily and then get sucked back into the cylinder as the piston pulls down for the intake stroke. Hence the fuel:air mixture will have less oxygen and might not burn, thereby causing a misfire when the spark jumps the gap at the right time (due to crankshaft positioning).

Q: What happens if cam timing causes the intake valve to open too late?
A: I guess in the beginning of the intake stroke, both valves will be closed momentarily, and when the intake valve belatedly opens, the air:fuel ratio will be 14:1 (because that's what was in the intake manifold) but there might not be enough fuel to actually burn when the spark jumps the gap to develop a good flame front by TDC when both valves are closed again.

Q: What happens if cam timing causes the exhaust valve to open too late?
A: I guess in the beginning of the exhaust stroke there will be too much compression and then all of a sudden the valve will open late and most but not all the exhaust gasses will be expelled. The result would be some exhaust gas left over so that the next power stroke will be less powerful, perhaps not enough oxygen to ignite when the spark jumps the air gap.

Q: What happens if cam timing causes the exhaust valve to open too soon?
A: In this case, there will be loss of compression on the tail end of the power stroke, I guess, and exhaust gases will again be left in the cylinder to cause havoc with the next 4-stroke pull-push-pow-puey cycle.

In all four of these cases, a misfire might occur but I must again be blunt about two concerns I have with this hypothesis:

1. If the VANOS caused valve timing to be off, how would it always be reliably rectified in the very next ignition cycle 30 seconds later?

2. If the VANOS caused the valve timing to be off, how would it only affect a single cylinder (particularly cylinder #4)?

I must say I do not understand VANOS well enough to answer those two questions - but before we hypothesize VANOS as the culprit, we must have the answer to those two questions in hand.

Last edited by bluebee; 02-25-2010 at 08:59 PM.
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  #61  
Old 02-25-2010, 08:36 PM
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Never one to shirk my duty (and stick my neck out) ... I'll make the first pass at what below satisfies BOTH requirements of being (probably electrically) reset with the next ignition cycle and affecting a single cylinder #4.

1--bad fuel (no on both counts)
2==trash or gunk in fuel (no on both counts)
3---spark plug valve cover seals (yes on only one count, no on the other)
4---head gasket leak, or cracked block (yes on one count, no on the other)
5---bad plugs (yes on one count, no on the other)
6==coil pack or boot (yes on one count, maybe on the other)
7---bad 02 sensors (no on both counts)
8---bad maf (no on both counts)
9---bad injector (maybe yes on only one count, maybe no on the other)
10---crack ring (yes on one count, but certainly no on the other)
11---cam shaft sensor (hmmm... if there is only 1 sensor, then no on both counts)
12==crank sensor (hmmm... same answer as cam sensor)
13---bad ground wires (yes on one count, probably no on the other)
14--- bad fuse or relay (no on both counts)
15---bad wireing (yes on one count, probably no on the other)
16--- dme, or ecu (yes on one count, maybe on the other)
17--intake manifold gasket leak (yes on one count, no on the other)
18--ccv--aka pcv (hmmm ... methinks no on both counts)
19--icv--idle control valve (hmmm... don't know enough to say)
20--tps==throttle position sensor (seems to be no on both counts)

Please correct me where I'm wrong - but very few things in that list which are known to cause a misfire will satisfy (IMHO) the reported conditions of being reliably reset with the next ignition cycle and affecting a single cylinder.

Please feel free to correct me if I am wrong.
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  #62  
Old 02-25-2010, 10:04 PM
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doru doru is offline
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You justforgot the vanos seals
On all counts....

I might be off, but:
imedietely after I replaced those seals, the car had the jittesr for a short time (seconds) and it was done (the first key after the repair). The vanos unit had no oil in it (was not "primed").
Prior to that (changing the seals) I experienced that hefty shudder, and once I had CEL coming up, which went off after I restarted the car.
I am not positive if this happened after the car sat for a while, but it might be so. In this case the original Vanos seals did let the engine oil by-pass, and then you end up with an "unprimed" vanos unit. Not sure how it works in this state, prolly it triggers the jitters - the firing sequence is disturbed. If one turns off the engine and restarts it, and the jitters are gone - it means the vanos is "primed" and kinda works close to spec (the seals are still shot, but the unit does not cavitate).

this is my 0.02 and I know I might be wrong, but since I did the Vanos seals, I did not experienced the jitters anymore, even after the car sat for a while.
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Last edited by doru; 02-25-2010 at 10:13 PM.
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  #63  
Old 02-26-2010, 01:21 PM
sktn77a sktn77a is offline
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Quote:
Originally Posted by bluebee View Post
"pull-push-pow-puey"
Ha - nice one! Was "suck-squash-bang-blow" when I learned it!



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  #64  
Old 02-26-2010, 01:54 PM
Neversaynever Neversaynever is offline
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All,
The primary challenge with debugging and the main reason for wanting to understand this common problem is that it is inconsistent. It is very hard to swap coils, change CCV, replace plugs in a systematic way when the problem comes and goes without any predictability. Even low air temps are not reliable in making this problem occur. It would be very helpful to find a way to create the problem which would obviously be a huge step toward fixing.
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  #65  
Old 02-26-2010, 02:12 PM
poolman poolman is offline
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I dunno anything much--but all of this has gone away since making the seal change--car is rock solid when cranking, and thats at all temps --even when it's down around 0--car cranks up like it's happy.
I give up on what this could be and what that could be--I'm just focusing on whats worked--had a buddy
back when I was on the road playing pool all over the country back in the 70's and 80's---we were great players and hit all the major cities--there were great players all over--and some who got SO caught up in
technique that they lost the ability to play well--sorta like the guys that are flying planes--something goes wrong and they are trying to figure out whats happening--they crash the plane--they forgot the first
function and directive--- FLY THE DAMN PLANE
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  #66  
Old 02-26-2010, 03:12 PM
Neversaynever Neversaynever is offline
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Man is there some truth in that, Poolman. (nice to know how you got the name) I have had only one cylinder loss problem since my VANOS. And interestingly, my problem only happened after the car sat idle for a few days. Sounds like oil could settle, Vanos pressure changes, blah, blah.
But like most everyone on this post, we are not too worried about how to work around the problem but instead what is behind it. We may never know but the learning for this exercise may make us all better at understanding these cars.
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  #67  
Old 02-26-2010, 06:06 PM
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lild lild is offline
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here is the problem. one cylinder missfired. why?
well even though were not interested in the fix, but the fix, will lead to why it happen. you can not pin point to one thing, that causes a single cylinder to misfire, the multiple things that i listed can cause it. why only one. who knows exactly. even an experince mech. could scratch his head over that, especially if it only happens once. to truely to find the answer, that same cylinder would have to misfire on a constant basis, and even then, and when the problem is has a sure fire fix, it could only pretain to your car. see your's misfire on #3, mine on #2, some else's #4. and all for differnt reasons.

as for fuel cut off. if you have a bad injector, then yes when you crank the car, and that cylinder won't fire, how ever, the car will start, but only on 5 cylinder. all the injectors don't feed the cylinder's at once. each pistion rotates at different times, and the injectors send fuel at diff. rates, that's why cars have timeing. and the injectors don't put fuel into the intake, they are at the very end of the intake, so fuel and air mix at the right time. also you can disconect one or two coil packs, and still start the car, you'll just have what you got that day when it runs, and a check engine light.
so if you've had just a misfire, then you would have gotten a misfire code.
if you had no fuel to start with then the car wouldn't have started
and the computer doesn't just does not, notl send fuel to one cylinder
you got a code for a misfire, a cylinder that did not fire at all, so then the computer shut off all fuel supply to that one cylinder. so you end up getting a misfire/fuel cutoff code.
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  #68  
Old 02-28-2010, 12:25 PM
mujjuman mujjuman is offline
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as far as i know, each fuel injector sprays fuel in each cylinder
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  #69  
Old 03-01-2010, 06:53 AM
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as far as i know, each fuel injector sprays fuel in each cylinder
Most fuel-injection systems spray into the manifold (IIRC). Certainly the cold-start injector doesn't spray directly into a cylinder. I'm still looking for a PDF of how the E39 fuel injectors work.

BTW, I did find an ingenious way to test for a vacuum leak, as per cn90 here.

And a nice way to test the mass-air-flow (MAF) meter hot-wire sensor here.

Again, a nice cn90 CCV/ICV cleaning/replacement here.





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Last edited by bluebee; 03-07-2010 at 07:29 AM.
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Old 03-01-2010, 08:44 AM
mujjuman mujjuman is offline
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ah, i see. thanks!
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Old 03-01-2010, 09:41 PM
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I'm hoping someone like QSilver will have a PDF of how the fuel injectors actually work that shows the timing between the 7 injectors on the I6.

Meanwhile, I've done nothing (placebo effect) and the problem has "fixed itself" (which is to say it's frustratingly rare and intermittent).

Having read everything I could find (always willing to read more if you have a good reference), I'm beginning to hypothesize the following sequence:

a) Misfire occurs in cylinder #4 for some reason (unknown why as yet but it could be a temperature/humidity/sitting-for-two-days glitch)
b) Misfire continues enough so that DME cuts off fuel for injector #4 (assuming fuel injectors fire directly into the cylinder in an '02 525i)
c) Apparently even if the misfire corrects itself, the fuel is still cut off from cylinder #4 FOREVER and ever (or until the next reset)
d) The ONLY thing that returns fuel to cylinder #4 is for the ignition to be cycled <=== this is my hypothesis based on my observations
e) When the ignition is cycled, fuel returns, and the minor glitch (I'm thinking it's due to software) doesn't occur on restart conditions

Please feel free to pick apart my hypothesis above as that's the only way we'll get to the bottom of this glitch.

Under this hypothesis, the minor problem of a software-confused misfire causes a more major stumbling when the cylinder is PERMANENTLY starved of fuel BECAUSE that fuel cutoff is never reset (so the hypothesis goes) until the ignition is cycled.

Does this hypothesis make sense?
If so, does it afford a test sequence for us to prescribe for when it happens to one of us?
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Last edited by bluebee; 03-07-2010 at 07:31 AM.
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  #72  
Old 03-01-2010, 11:39 PM
mujjuman mujjuman is offline
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Quote:
Originally Posted by bluebee View Post
I'm hoping someone like QSilver will have a PDF of how the fuel injectors actually work.

Meanwhile, I've done nothing (placebo effect) and the problem has "fixed itself" (which is to say it's frustratingly rare and intermittent).

Having read everything I could find (always willing to read more if you have a good reference), I'm beginning to hypothesize the following sequence:

a) Misfire occurs in cylinder #4 for some reason (unknown why as yet but it could be a temperature/humidity/sitting-for-two-days glitch)
b) Misfire continues enough so that DME cuts off fuel for injector #4 (assuming fuel injectors fire directly into the cylinder in an '02 525i)
c) Apparently even if the misfire corrects itself, the fuel is still cut off from cylinder #4 FOREVER and ever (or until the next reset)
d) The ONLY thing that returns fuel to cylinder #4 is for the ignition to be cycled <=== this is my hypothesis based on my observations
e) When the ignition is cycled, fuel returns, and the minor glitch (I'm thinking it's due to software) doesn't occur on restart conditions

Please feel free to pick apart my hypothesis above as that's the only way we'll get to the bottom of this glitch.

Under this hypothesis, the minor problem of a software-confused misfire causes a more major stumbling when the cylinder is PERMANENTLY starved of fuel BECAUSE that fuel cutoff is never reset (so the hypothesis goes) until the ignition is cycled.

Does this hypothesis make sense?
If so, does it afford a test sequence for us to prescribe for when it happens to one of us?
until ignition is cycled or CEL is cleared using OBD tool.... I do this even while driving... I just stick a scan tool in there and delete the code. As soon as it clears, its like brand new again.

It happens on cold morning starts 90% of the time... the other 10% it happens to me randomly. Today on hwy it happened while i was going about 72mph... i had been driving for 3 hours and all of a sudden the car hiccuped a few times before fuel was cut to the cylinder. I simply attached my scanner and deleted the code, and instantly the car was fine again.
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  #73  
Old 03-02-2010, 01:23 PM
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bluebee bluebee is offline
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Location: San Jose, California
 
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Mein Auto: 02 BMW 525i M54 auto 130K
Quote:
Originally Posted by mujjuman View Post
I simply my scanner and deleted the code, and instantly the car was fine again.
Interesting datapoint. If we're to come up with a realistic diagnostic sequence, we'll need to catch the error in the act and debug from there.

To that end, two quick questions:
Q1: What was the PXXXX error you get?
Q2: Did I hear that right that, without cycling the ignition, simply clearing the code (while the engine is operating with the fuel cut off to a cylinder) causes the fuel to that cylinder to be turned back on?

Please reply as I'm dying to know the answers!
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  #74  
Old 03-02-2010, 01:37 PM
Neversaynever Neversaynever is offline
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Bluebee, Mujjuman has the perfect situation to solve this. He gets the problem 90% of the time on cold starts. You and don't see it but once in a blue moon. And yes, he said he can clear the code and the problem while driving - on the fly! So, by circumstantial deduction, something triggers the computer to shut down #4 and clearing to code release fuel to #4. I am still thinking VANOS but curious.
And BTW, my '02 525 sat for 4 days in the cold and started smooth as usual just this week. I was almost assured of a misfire start if this had been pre Vanos and pre new plugs.
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  #75  
Old 03-02-2010, 02:51 PM
mujjuman mujjuman is offline
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A1: I get a P1345 code... Which is same thing except for cyl2... I think our problem is the same though, because I get this code everytime.
A2: yes that is correct.... By deleting thecode while the engine is still running and not actually cycling the ignition, the everything returns to normal and all my injectors work normal again.

I really want together this fixed... I recently got my CCV system replaced, but it is faultly so Im having the shop look at it again. I hope we can solve this together, lol.
Have you tried replacing sparkplugs? I haven't done that after replacing my CCV, and they were noticably corroded.
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