Strange starting behaviour

M

mcbutler

Veteran
 Plymouth
Hello all,
35i with 33k miles.
During my ownership odf this fabulous car it has always started perfectly, running smooth as silk from wqarm or cold.
Last three cold starts have been a bit rough though, it stutters for a split second before adopting its usual growl.
I will try and catch it on camera next time.
Anyone got any ideas??
 
Agree with smartbear, pull the spark plugs out after it’s been stood several hours and see if any are wet
 
Injector or fuel pump. Easy way to check fuel pumps is to monitor the fuel rail pressure during start using MHD, ProTool or INPA.

Injectors are a bit more involved to test, the wet plug test doesnt always work.
 
I'd clean vanos solenoids, reset adaptations both fuel and vvt

next would be checking MAF and intake manifold pressure, if the first doesn't bring the desired result

if still present, check adaptations additive, multiplicative - based on these decide whether it is injector or spark plug, supposing there's no vacuum leak
 
tintoverano said:
I'd clean vanos solenoids, reset adaptations both fuel and vvt

next would be checking MAF and intake manifold pressure, if the first doesn't bring the desired result

if still present, check adaptations additive, multiplicative - based on these decide whether it is injector or spark plug, supposing there's no vacuum leak
Click to expand...

N54 has no MAF and MAP reading will have no effect on startup. Having no MAF also means that a vacuum leak won't cause a problem at startup or idle.

Also car operates in open loop fuelling at startup so not either of those trim values will be relevant.
 
If you want a base for comparison while troubleshooting this issue here's a log of what a cold start looks like on a healthy car:
https://datazap.me/u/rich/cold-start-vanos?log=0&data=3-14-15-19-20-23-24&solo=19-24

You want to compare your high pressure fuel reading and AFR according to that log to pinpoint your issue. We have no low pressure fuel sensor on the Z4 so the only way you can verify the low pressure pump is working is to start recording the log before starting the car, on mine you see the rail pressure is at 72PSI which is exactly what the electronic fuel pump in the tank should be doing, if less than 60 you have issues with that pump. If your rail pressure doesn't quickly get above 2000 right after starting then your issue is with the high pressure fuel pump.

If the pressure reading is good you should then focus on the AFR. If the AFR differs largely between the two banks or is a lot richer or leacher than 15 then it's very likely injector related provided the rail pressure was OK.
 
R.E92 said:
If you want a base for comparison while troubleshooting this issue here's a log of what a cold start looks like on a healthy car:
https://datazap.me/u/rich/cold-start-vanos?log=0&data=3-14-15-19-20-23-24&solo=19-24

You want to compare your high pressure fuel reading and AFR according to that log to pinpoint your issue. We have no low pressure fuel sensor on the Z4 so the only way you can verify the low pressure pump is working is to start recording the log before starting the car, on mine you see the rail pressure is at 72PSI which is exactly what the electronic fuel pump in the tank should be doing, if less than 60 you have issues with that pump. If your rail pressure doesn't quickly get above 2000 right after starting then your issue is with the high pressure fuel pump.

If the pressure reading is good you should then focus on the AFR. If the AFR differs largely between the two banks or is a lot richer or leacher than 15 then it's very likely injector related provided the rail pressure was OK.
Click to expand...
Good solid info, thank you.
Do you know if carly offers this info?
Also noticed recently that when giving it some 'beans' as the revs get high the car sounds like it is surging, (a bit like the noise you get as you pass a lamp post and the engine sound is momentarily reflected back to you). I cannot feel the urging or see anything on the rev counter though?
Related maybe!!
 
I don't think Carly does data logging, it's just for superficial coding. DeepOBD might work but I haven't tried.

I know for certain ProTool is capable of reading those parameters. If you're paying for a Carly subscription you would be best cancelling it and buying ProTool. It does everything Carly does and more and it's not subscription based or VIN locked.
 
I bought Carly pre subscription!
Protool looks good but I avoid android like the plague, had my samsung 'smart phone' hacked by some ass hole they sold my debit card info and the criminals who bought it ordered a total of over £350 worth of deliveroo... Guy at the bank said a child can hack an android phone and it happens all the time!!!!!!!!!!
Devout apple user now....... Soon as they do protool for apple I am in.....
 
mcbutler said:
I bought Carly pre subscription!
Protool looks good but I avoid android like the plague, had my samsung 'smart phone' hacked by some ass hole they sold my debit card info and the criminals who bought it ordered a total of over £350 worth of deliveroo... Guy at the bank said a child can hack an android phone and it happens all the time!!!!!!!!!!
Devout apple user now....... Soon as they do protool for apple I am in.....
Click to expand...

Many people have begged Bimmergeeks to do an IOS version...however there focus is on extending the range of BMW cars they support..F and G series and even going back to earlier Es.

With 6 iPhones and 4 iPads in our house you can say we are Apple oriented.

I just bit the bullet and bought a dedicated rugged Android phone for £80 and use that solely for Protool.

No danger of being hacked then.

https://www.amazon.co.uk/dp/B07V1PM1FJ/ref=sspa_dk_detail_2?psc=1&pd_rd_i=B07V1PM1FJ&pd_rd_w=izaZC&pf_rd_p=871455a8-2081-4ae3-be47-0e6ec29adb28&pd_rd_wg=pVNQC&pf_rd_r=HNJ13Q590JZ03GWS44T4&pd_rd_r=02cf500b-5309-416f-aa68-9d4cc3257807&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExNk5WQjY3UTY0WlE0JmVuY3J5cHRlZElkPUEwNTM4Mzc5TFJCMThZTzFaQ0ZTJmVuY3J5cHRlZEFkSWQ9QTA3NTkxNjgzNjQ0S0IySFE0OVpFJndpZGdldE5hbWU9c3BfZGV0YWlsJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

You just to make sure it supports OTG which is the USB support to allow you to plug in a usb to OBDII connector :thumbsup:
 
The guy at the bank has no idea what he's talking about. Security wise both Android and iOS are solid, the security breaches that do happen are often a result of phishing attacks not unauthorised device access.
 
R.E92 said:
The guy at the bank has no idea what he's talking about. Security wise both Android and iOS are solid, the security breaches that do happen are often a result of phishing attacks not unauthorised device access.
Click to expand...
Well Norton disagree, do you believe them ??!!
https://uk.norton.com/internetsecurity-mobile-android-vs-ios-which-is-more-secure.html
 
mcbutler said:
R.E92 said:
The guy at the bank has no idea what he's talking about. Security wise both Android and iOS are solid, the security breaches that do happen are often a result of phishing attacks not unauthorised device access.
Click to expand...
Well Norton disagree, do you believe them ??!!
https://uk.norton.com/internetsecurity-mobile-android-vs-ios-which-is-more-secure.html
Click to expand...

Article has some valid points but they are user error and not a fault of Android. Any out of date OS is a risk, iOS has some nasty security flaws too so both are equally at risk if not updated.

The only inherent increased risk with Android versus iOS is that it allows users to run software that isn't signed by the creator of the OS. I personally think that's a perk but it can be a vulnerability, there are plenty of warnings before installing applications from other sources. It's kid of like saying a fast car is less safe than a slow care because it allows people to drive faster, the car isn't inherently less safe rather the driver has more room to make mistakes.

The probability is that your credit card data was stolen as a result of a data leak from a company or from you entering the details into an unsafe or phishing website. That is just as likely to happen on iOS.
 
Well, I have had the car to my indy for 4 days, they ahve been through everything no codes, all injectors(gen6), plugs, coils etc etc checked ok. MAP removed, all still the same, map reinstalled and still all ok!
Test driven several times with no symptoms!!!

Conclusion by the guys at RL is possible 'bad fuel'! Apparently a large number of cars have been stood for a long time due to various lockdowns. I filled it with a fresh tank of Shell V before i took it in so fingers crossed and worth bearing in mind if anyones dragging their car out of mothballs this week....

In addition Bernard at carly sorted me out so I can transfer my app to my iphone and a new adapter :-) Super happy, I can finally chuck that god awful galaxy note android shite in the bin........ Mind you give it its due, it lasted 12 years, only kept it to run carly though......
 
mcbutler said:
... Conclusion by the guys at RL is possible 'bad fuel'! Apparently a large number of cars have been stood for a long time due to various lockdowns.
Click to expand...
If this is the case and it may well be, is it possible that a substantial quantity of fuel has been held in storage depots and has gone 'bad' there, too?
 
Busterboo said:
mcbutler said:
... Conclusion by the guys at RL is possible 'bad fuel'! Apparently a large number of cars have been stood for a long time due to various lockdowns.
Click to expand...
If this is the case and it may well be, is it possible that a substantial quantity of fuel has been held in storage depots and has gone 'bad' there, too?
Click to expand...
Thats a fair point chum ...
 
I think you're OK at filling stations now, the roads have been fairly busy all winter, it was only the first lockdown that people stopped using their cars.

Over the last couple of months I've turned up at a few filling stations that have run out of diesel or standard petrol so it's not like the fuel is just sitting in the tanks.
 
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