Jump to content
Oneball

E39 540i Misfire Rough Running

Recommended Posts

49 minutes ago, Oneball said:

Thanks, I've put the coils from the Alpina in and it made no difference.

 

The company I sent the ECU off to have been unable to test it, so they're sending it back FOC, I've spoken to a few others about testing V8 ECUs so far without a positive response.

 

 

 

Might be a bit on the extreme side but if you cant find someone to test your ecu you could try another v8 ecu but you would need a kit, ecu, ews unit, key etc.....

Edited by 530d titansport

Share this post


Link to post
Share on other sites
1 hour ago, cawmere said:

Did you use BW Chiptune?

No, they were supposed to get back to me but didn't, might try them again, thanks.

Share this post


Link to post
Share on other sites
38 minutes ago, 530d titansport said:

 

Might be a bit on the extreme side but if you cant find someone to test your ecu you could try another v8 ecu but you would need a kit, ecu, ews unit, key etc.....

Thanks, I have found somwehere that will supply a used ECU and code it but they weren't interested in testing mine so I left it.

 

I'm borrowing a crank sensor off a friend's M3 at the weekend (apparently they're the same) if that's no joy I'll get back on the ECU

Share this post


Link to post
Share on other sites
22 minutes ago, Oneball said:

No, they were supposed to get back to me but didn't, might try them again, thanks.

Worst case they can build you a new ECU. Good luck...Jason is a bit hard to get hold of sometimes.

Share this post


Link to post
Share on other sites

Haven't got any further with the ecu but it's not the cam or crank sensor. 

 

Was thinking about broken cats. So taped up the exhaust leaving a 5mm gap on one side and it made the problem only a tiny bit worse which was surprising so I'm thinking maybe there is an issue with the cats even though I've run it with the lambda sensors out and it made no difference. Need to try and definitively rule it out. 

 

 

Share this post


Link to post
Share on other sites
17 minutes ago, Oneball said:

Haven't got any further with the ecu but it's not the cam or crank sensor. 

 

Was thinking about broken cats. So taped up the exhaust leaving a 5mm gap on one side and it made the problem only a tiny bit worse which was surprising so I'm thinking maybe there is an issue with the cats even though I've run it with the lambda sensors out and it made no difference. Need to try and definitively rule it out. 

 

 

 

I didnt have any issues... well i didnt thing i did till i dropped my exhaust off to make some mods to it and after removing the back box the contents of the cats came out!!! I was rather shocked to see that in the back box but since refitting my exhaust with a fresh backbox the car goes like stink!!! It mush have been partly blocked but not enough to cause any lights to come on. Pull your exhaust off and have a good look at them cats.

Share this post


Link to post
Share on other sites

Got the exhaust off and there's nowt inside and the cats look good. So that's another thing ruled out, twice!

 

I've managed to find someone who seems to know what they're talking about with ECUs and with the symptoms I have they don't think bench testing the unit will give a definitive answer as to whether it's the problem. So they've suggested coding a replacement ecu that I can put in to see if it fixes the issue on a return basis with a restock fee if it doesn't. So gone with that. 

Share this post


Link to post
Share on other sites

That looks really smart.

 

Couldn't sell it unless it was working properly. May break it if I can't fix it. 

 

Has anyone had flex plate/starter ring/flywheel issues on an M62 auto?

 

i could change all 8 coils but that's expensive and I've put the 6  out of the Alpina in there and it didn't make a difference. 

 

 

Share this post


Link to post
Share on other sites

Decided to start at square one again! Fuel, ignition, air, compression.

 

Tested the fuel pressure at the rail again.

 

i-5wG3Vk6-L.jpg

 

 

Which is well down on what it is supposed to be, it does increase when there's no vacuum to the pressure regulator.

 

So the question is, "What is the problem?"

 

Pump, regulator or a blockage????????????

Share this post


Link to post
Share on other sites
1 hour ago, Oneball said:

Decided to start at square one again! Fuel, ignition, air, compression.

 

Tested the fuel pressure at the rail again.

 

i-5wG3Vk6-L.jpg

 

 

Which is well down on what it is supposed to be, it does increase when there's no vacuum to the pressure regulator.

 

So the question is, "What is the problem?"

 

Pump, regulator or a blockage????????????

 

Whats the live data on inpa say for the inline pump?

Share this post


Link to post
Share on other sites

I haven't got a reading in INPA for the pump. There is just the in tank pump on mine. 

 

It is a little weird as as I checked the pressure previously and it was 3bar and 3.5bar at wide open throttle. 

 

The misfire hasn't changed since then but now the fuel pressure is low. 

Edited by Oneball

Share this post


Link to post
Share on other sites
8 minutes ago, 530d titansport said:

Poss a collapsed fuel filter? Or bad regulator

Fuel filter is new. 

 

I can't work out in my head if a bad regulator would give low pressure and still give you the 0.5bar increase at WOT which it does. 

Share this post


Link to post
Share on other sites

Cheers.

 

Couldn't be bothered crawling under the car at 7 this morning to check the filter outlet, going to take a chance and get a new regulator on the way home from work. I'd however put money on it not fixing the misfire even if it fixes the pressure!!!!!!!

Share this post


Link to post
Share on other sites

Regulator changed, fuel pressure fixed.

 

i-XmcqCBg-M.jpg

 

i-M6Svf9q-M.jpg

 

And guess what, the misfire is still there.

 

What is it with this car I've fixed about a gazillion things that will cause it to not run properly and not one of them has fixed it?!

Share this post


Link to post
Share on other sites

Injectors have been tested and one was duff and was replaced. Made no difference. And I've now got a different set in out of an X5 that are known to be good just in case they weren't ok and that's made no difference. 

Edited by Oneball

Share this post


Link to post
Share on other sites

Sounds like a total head melt. If the problem is following the injectors when you swap them around then that suggests it's related to the FI rather than ignition. I'm sure you've thought of this, but have your tried dousing everything electrical with shed loads of WD40 and see if it makes any difference at all (other than a big mess)?

Share this post


Link to post
Share on other sites

Yep!! Argh. 

 

The problem doesn't follow injectors or coils or plugs etc. Looking at the smoothness data in INPA it moves around. It's present at all times and all revs, hot or cold. So it must be something that affects everything e.g. Inlet, maf, etc. But I've ruled them all out, I think. 

 

Thanks. Ive had a fiddle with all the connectors but without effect. 

Edited by Oneball

Share this post


Link to post
Share on other sites

I've fixed a couple of vacuum leaks (manifold gaskets, and broken pipe). I've replaced the PCV valve which was cracked. And it all made no difference. I've done about 5 vacuum tests and my local Indy has done a smoke test. So I'm pretty sure it's not a vacuum leak even though the symptoms suggest that. 

 

Ive even checked the cam timing and that's ok. 

 

Ive measured the ignition timing with a stobe and it was in the ball park for a Ford v8 (couldn't find any details of M62 timing) it also advanced with revs. 

 

Thanks again. There's no stupid ideas or obvious posts. As it's got to be something. 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×