[achu]

hi guys i feel so bad because I don't really post much anymore (i do however read your threads when i'm free, so dont think i'm just using you lol)

anyhoo, my car is an e93 335i on 77k with a JB4...

i'm having a misfire issue but it's a strange one... i really don't want to make a long ass post as i know they're annoying to read!

basically if i put my foot down more than about 50%, i get a loss in power (almost like the traction control kicked in) and then a misfire... the engine management light doesn't come up though... nor does the limp mode message...

after about 20 seconds of misfiring at idle, the car goes back to normal... and drives like normal if i drive gently... i can also get the misfire to go if i just restart it... the misfire doesn't go if i keep driving...

also when driving a bit rapidly (but not putting my foot down) i can feel tiny moments of loss of power, almost like the car is hesitant... it's so slight a passenger probably won't feel it but i can... and it happens around once or twice every 15mins...

the crank is snappy and sweet, idle is very steady and revving in neutral is perfect all the way to redline... i have a JB4 installed (i was on map 5) but this happens at map 0... i've replaced my coil packs (they were the originals) and spark plugs (might as well) but no joy...

when i checked the codes the first time, i had:
29DC Cylinder injection switch-off
29CF Misfirings, cylinder 3
29D0 Misfirings, cylinder 4
29CC misfire, multiple cylinder

but I think these may have been stored from before... I cleared them and did a WOT pull to get the problem to happen and read the codes immediately after:
29DC Cylinder injection switch-off

I'm thinking it's the LPFP but I don't want to guess as I don't have the time and this car is my daily......

any help would be greatly appreciated!

(some extra info: the car had a few hiccups over the last few months under WOT - the car would lose power, EML would come on and then go in a minute... this happened about 3 times in 4 months... also every now and then, if rev up slowly but all the way to 4k or so in gear 2 (going up a hill or something), the limp mode light comes up and then goes in 5mins or so)

i've posted up in the official n54 misfire thread, but just incase you guys don't see it, i thought i'd copy it here...

[achu]

oh and i've tried to research my problem for so long but can't find someone who has the same symptoms...

similar symptoms go when they do a coilpack change, but as i've said, i changed them with the plugs...

if any more codes pop up, i'll post them up...

thank you so much in advance! much love

[achu]

so after work, i took the car and accelerated hard to get the misfire to come up to see if more codes came up, this is what came up:

29dc - cylinder injection switch-off

same as before...

i then held the acceleration until the CEL came on (the car would rev to 5k and stop) so i knew the car threw up some more codes, this is what came up:

29d1 - Misfirings, cylinder 5
29ce - Misfirings, cylinder 2
29cc - combustion misfires, multiple cylinders

and then i went up a hill and held the revs at 3k until the limp mode light came up and this is the code i got:

29f2 - fuel high pressure system, fuel pressure

this is my thinking:
- it's not HPFP cos the crank is quick and smooth
- it's not the injectors cos the same cyclinders aren't misfiring (before it was 3 and 4)
- it's not the vanos solenoid because the idle is silk smooth

it must be the LPFP right?!!?

[AlanYoro35i]

Achu


Has your injectors been recalled before?

[achu]

Originally Posted by AlanYoro35i

Achu


Has your injectors been recalled before?

i'm not sure, i'll need to call and check...

[Phil325i]

Be aware the LPFP has its own control unit which can fail (mine did). I suggest you seek out an indy who has the latest BMW diagnostic software. This works with the engine running and can detect issues not shown in normal fault codes.

[Dann]

Hpfp failure doesn't always mean long crank. Its just one of the potential symptoms

I'd start by chucking a set of plugs in it.

[old grey steve]

Sounds like your car come of the age Achu where things seem to take place.

On coils for a start (I might get shot down here) despite best intentions we've seen the odd Bosch set bought from places like GSF, Euro not locating 100%, bare in mind the plug well's quite deep if these don't 100% locateand we've seen it, plugs are another touchy subject on these as well again to a degree depends on where these came from.

On the rest of it difficult seem shed loads of these cars including my own and they can lead you a merry dance, the 29DC code can related to boost control from memory but don't rule out other issue as well, 2AAF would state fuel pump plausibility, but it doesn't have to show a code to actually prove an issue seen this before including my car like wise LFP sensor and the modified rail can be replaced(which I did on mine)and that made a difference even though there were no codes. Again on the HPFP "it's not HPFP cos the crank is quick and smooth"-sadly not the case achu, that's just one symptom, common nevertheless but its just one symptom. Codes like 29F2 29DC would again code wise lead you to a HPFP, but again codes don't have to show to indicate the pump's had its day

Vanos solenoid can play up "it's not the Vanos solenoid because the idle is silk smooth" not the case again as these can play up as revs and load rise for instance we've got a 335i E93 in here now with an erratic running issue 2A87 Vanos solenoid mechanism comes up, its sporadic, but seen these codes before and oddly enough there can be something a little different behind it, oddly enough and it is odd I know but there's a reason behind it on this car we've replaced the exhaust cam sensor and everything spot on now

29CF Misfiring, cylinder 3, 29D0 Misfiring, cylinder 4, 29CC Misfire, multiple cylinder's is again not unknown not unheard off but it can again lead to may causes. Interesting one is 29DC Cylinder injection switch-off on paper the code actually comes through as a possible low pressure fuel issue

Other possible issues come back in my mind to injectors seen these leak sometimes without codes as well, we also know achu about coked up valves and what they can do, remember on injectors you just can't replace 1 or 2 you need to look at replacing 3 at a time for each cylinder bank..

Best advise I can give you is to get it diagnosed rather than stabbing at different conclusions achu, sounds direct but seen these sort of things too many times before and I know how bloody annoying all these things are, but always remember to expect the unexpected .

[achu]

Originally Posted by Phil325i

Be aware the LPFP has its own control unit which can fail (mine did). I suggest you seek out an indy who has the latest BMW diagnostic software. This works with the engine running and can detect issues not shown in normal fault codes.

i'm gonna let Steve @ A1BN look at it if he's free, I don't wanna waste any more time...

Originally Posted by Dann

Hpfp failure doesn't always mean long crank. Its just one of the potential symptoms

I'd start by chucking a set of plugs in it.

Yeah it's just something I kept reading so I wasn't sure... I've changed my plugs and coils, it woulda been nice if that fixed it but knowing my luck i knew it wasn't going to lol...

Originally Posted by old grey steve

Sounds like your car come of the age Achu where things seem to take place.

On coils for a start (I might get shot down here) despite best intentions we've seen the odd Bosch set bought from places like GSF, Euro not locating 100%, bare in mind the plug well's quite deep if these don't 100% locateand we've seen it, plugs are another touchy subject on these as well again to a degree depends on where these came from.

On the rest of it difficult seem shed loads of these cars including my own and they can lead you a merry dance, the 29DC code can related to boost control from memory but don't rule out other issue as well, 2AAF would state fuel pump plausibility, but it doesn't have to show a code to actually prove an issue seen this before including my car like wise LFP sensor and the modified rail can be replaced(which I did on mine)and that made a difference even though there were no codes. Again on the HPFP "it's not HPFP cos the crank is quick and smooth"-sadly not the case achu, that's just one symptom, common nevertheless but its just one symptom. Codes like 29F2 29DC would again code wise lead you to a HPFP, but again codes don't have to show to indicate the pump's had its day

Vanos solenoid can play up "it's not the Vanos solenoid because the idle is silk smooth" not the case again as these can play up as revs and load rise for instance we've got a 335i E93 in here now with an erratic running issue 2A87 Vanos solenoid mechanism comes up, its sporadic, but seen these codes before and oddly enough there can be something a little different behind it, oddly enough and it is odd I know but there's a reason behind it on this car we've replaced the exhaust cam sensor and everything spot on now

29CF Misfiring, cylinder 3, 29D0 Misfiring, cylinder 4, 29CC Misfire, multiple cylinder's is again not unknown not unheard off but it can again lead to may causes. Interesting one is 29DC Cylinder injection switch-off on paper the code actually comes through as a possible low pressure fuel issue

Other possible issues come back in my mind to injectors seen these leak sometimes without codes as well, we also know achu about coked up valves and what they can do, remember on injectors you just can't replace 1 or 2 you need to look at replacing 3 at a time for each cylinder bank..

Best advise I can give you is to get it diagnosed rather than stabbing at different conclusions achu, sounds direct but seen these sort of things too many times before and I know how bloody annoying all these things are, but always remember to expect the unexpected .

thank you Steve! you always have the best posts... expect a PM from me lol

[old grey steve]

Originally Posted by achu

i'm gonna let Steve @ A1BN look at it if he's free, I don't wanna waste any more time...

thank you Steve! you always have the best posts... expect a PM from me lol

No worries another issue that can cause a misfire and I had it and didn't mention it earlier is this




a cracked rocker cover when warm the rocker cover expans crack appears oil weeps out and drips down the injector sadly gets coated and you get a misfire. Same goes for the gasket should it weep internally



the picture above is a plug well from a 335i the metal sleeves are there as a barrier of sorts when the rocker cover weeps internally oil can seep through (sleeve's No7 on this picture http://bmwfans.info/parts-catalog/E9...er_head_cover/ if you look at the picture above you'll notice its slightly stained (slightly discoloured compared to the one below.




Look carefully at the picture below and you'll see a bit of oil here and there




and here's another that's slightly different and shows again where oil can linger



As I said although you quite rightly have codes(and there's a shed load of info as to what in theory these codes should lead too) the cause sometimes is not what you'd natrually think and as said at times with these cars expect the unexpected

[Dann]

If the valve cover isn't cracked it may just need a new gasket (just so happens I have one for sale)

I had a cracked valve cover and it leaked oil into the spark plug wells and the injector wells which meant my plugs and injectors got soaked in oil. Which was a contributing factor to my misfore along with a leaky injector or two.

I have some used injectors for sale (very cheap) which are okay if you wanted to try different combinations of things.

[Russbmw]

Has the intake been walnut blasted?

I assume you read the thread on mine?

[old grey steve]

Originally Posted by Russbmw

Has the intake been walnut blasted?

I assume you read the thread on mine?

For sure Russ. walnut blasting will help hence I've done mine and we've done a good 50+ cars since but looking at the info Achu has posted I'd expect it to be more than just one symptom but yes it will help just realised I hadn't even mentioned it above earlier. Shame on me

[Rialas]

Originally Posted by achu

i'm gonna let Steve @ A1BN look at it if he's free, I don't wanna waste any more time...



Yeah it's just something I kept reading so I wasn't sure... I've changed my plugs and coils, it woulda been nice if that fixed it but knowing my luck i knew it wasn't going to lol...



thank you Steve! you always have the best posts... expect a PM from me lol

Hi achu.
Hi are you getting on with this.

Only had my car a few weeks,
Car went into limp mode a few times but would reset after turning engine off. Then the charge pipe blew which I changed myself for an upgraded alloy one, but again the management light has come on a couple of times since.

The more I read, I'm more inclined to take it to someone that knows what they're doing. Don't want to be chasing problems by guess work.


Steve!! We need you.


I'm in Hertfordshire so a trip to Stevenage is doable.
Cheers.
Costa.

[old grey steve]

Well all being well achu's car will arrive tomorrow morning, it'll be a stayer I suspect for a few days partly down to our workload but more down to ensuring we measure twice cut once.

It'll take some decent time to diagnose sure you've got codes but codes may/can give you a bum steer as has been seen in many a thread before. But we'll find it but what it is

[old grey steve]

Well Achu's car with us




here's what we've seen so far apart from the diag which produced the very codes achu's already highlighted we saw the ususal 30FF code along with another code (can't for the life of me remember at this time)plus we can get it to splutter pop and bang when under some load static.

But judging by what we'd seen the inelt came off late this afternoon








the above's a damn fine place to start, yet again another well coked up and gummy set of inlet's, so this will need attending too, other stuffs on going strongly suspect from the live data that the HPFP is a little off coilur, coils, plugs, injectors will be looked at over the next few days but for now the cars wrapped up

[old grey steve]

Today in between other cars








even from a distance you can see how clean the ports are



HPFP also replaced as this was 100% suspect.. so over the next few days we'll button things up and see what emerges but the above is going to help .... fact

[phil200tdi]

Replace all the vacuum lines whilst you are there!

[Rialas]

Following with interest. Nice work.

[windymissile]

Just out of curiosity, and excuse me if I missed it, what fuel do you use??

WM

[old grey steve]

Well the good news is it's all sorted the HPFP under load was fluctuating wildly we could clearly see this so knew 100% that this needed attending too, plus of course the valves like every 335i we've seen we're coked up as you can all see, the valves we all know can create misfire issues and visually everything backed this up, there was another fault lurking behind the scene which required changing the 2 pressure converse the vac lines were checked and dealt with accordingly. Injectors are fine, plugs are fine no visible issue re leaks at the top so that's good news and smooth running once everything was back together was spot on.

We drove it yesterday with JB4 off/on no issues either way, we are going to once again run the car up at the start of the week, re check everything to ensure we are comfortable with what we've done then that's it.

The one thing though that we will do on Monday is to put the car on the MOT bay, reason the cars soooooo low to look on any of our standard ramps we simply cannot get the car on any of them without damaging the car or the ramps.

[achu]

Originally Posted by windymissile

Just out of curiosity, and excuse me if I missed it, what fuel do you use??

WM

only ever Shell V-Power in my 2 year ownership (but the car is coming up to 9 years old so who knows what she's been fed for the previous 7)