[DannyG04]

Hey, just looking for some guidance on what to start looking at next on fixing an ongoing issue. Upon cold starting the car it will precede to have a really lumpy idle and cause cylinder 5 to stop firing all together till I restart the car. Only option so far to get to work is to start it and then start driving which I don’t really want to be doing but once the car heats up a little the problem goes all together. I’ve attached the codes I’ve got up for the car at the moment, I initially had codes for both the heater control circuits for both post-cat O2 sensors which I’ve replaced with Bosch sensors and I’m no longer getting codes for them, spark plugs were done 20,000 miles ago, I’m guessing it could be the other O2 sensors but I was just seeing if there is a common issue that’s something else since I’m not getting codes for the pre-cat sensors. Thanks.

[TunafishE93]

Swap coils to see if that follows, while you in there check plug. If that all checks out then injector would be next.

[Gizm0]

Sounds like leaky injector. After the car sits all night, the pressure in the fuel rail (about 1500psi) leaks fuel inside cylinder 5, so when you first start it in the morning, it will run rough/rich until all that extra fuel that has been sitting on top of the piston is burnt. When you restart the car, it starts normally since all that extra fuel is gone.

In the morning, remove spark plug from cylinder 5, and remove spark plug from another cylinder. If you have a strong fuel smell coming out of 5 and not out of other cylinders, the injector is your culprit. If you have a borescope camera, you can also stick it down in there to check the top of the piston for gasoline sitting there.

If you have the means to, you can also monitor the fuel pressure (monitor the high pressure, after the HPFP, not the low pressure between the pump in the fuel tank and the HPFP) when the engine is off, key in accessory mode. It should hold pressure when the engine is off, you may lose a few psi over the course of 10-15min, but if the pressure rapidly drops, then you have a leaky injector.

These piezo injectors are expensive...

[eljay]

I think most banks are running rich.





p.s. Follow the answers above.

[Gizm0]

Originally Posted by eljay

I think most banks are running rich.





p.s. Follow the answers above.

They really arent. If everyone was to pull all the money out of their checking/savings accounts all at once, banks would go under.

[DannyG04]

I’ll have a look at the cyclinder this weekend and dig out the borroscope from somewhere in the garage, praying it isn’t the injectors from a money aspect but I’ll let you know. Cheers for the help.

[gbalthrop]

Originally Posted by DannyG04

... Upon cold starting the car it will precede to have a really lumpy idle and cause cylinder 5 to stop firing all together till I restart the car. Only option so far to get to work is to start it and then start driving which I don’t really want to be doing but once the car heats up a little the problem goes all together. I’ve attached the codes...

What makes you think "Bank 2 Running Rich"?
What is the Variant/SGBD of your DME?

I'm NOT familiar with the N53 engine, but I thought that used the MSD80 DME. If so, the "29E1" Code which you report means Bank 2 is TOO LEAN. Here is a link to the BMW Fault Code Lookup Fault Info Sheet for 29E1:
https://bmwfault.codes/DiagView?id=M...E2MzExODcwNQ==

Scan Tools & Diagnostic Software, such as INPA & ISTA, are able to do MUCH more than simply read & clear fault codes. Good software, such as INPA or ISTA will tell you what variant each of your ~ 20 Modules is, & tell you the correct definition (Fault Details) of each Fault Code. You can display Live Data that will show you what the O2 Sensor on each bank is doing, in Real Time, & whether the mixture is Lean or Rich in that Bank.

Diagnose, don't GUESS,
George

[DannyG04]

I only said it was rich from me searching the code and it stating it’s a code for mixture control meaning it could either be rich or lean, and with a strong smell of fuel out the back on start I assumed the latter. Also tried for ages to get INPA to recognise the car for ages to no avail, communicated with my E46 just fine however.
Definitely going to assess first before I narrow down to any component 👍

[TunafishE93]

Truthfully you are either spark or fuel, takes ten minutes to switch coils and check the plug. Ten minutes to tell you if its the injector. You could have already diagnosed this without a computer

[DannyG04]

Unfortunately I haven’t been able to get a look at the sparks this weekend but a new code has come up putting a light on the dash, 29F1. Hoping it’s not the HPFP since I’ve already done that 20,000 miles ago but could it be a pressure sensor? Checking the rail pressure while I’m driving it sits at 20,000kPa while dipping to 17k when I let off and coast

[DannyG04]

The problem gets more interesting, having taken the coils and sparks out I was straight away met with oil in the wells which I have since cleared and will add the valve cover gasket to my list again on bits to do. Having a look at cylinder 5 and the others I weren’t met with any signs of fuel through damp on the inside or a smell so I’ve put it down to oil on the coils, plus sparks 5 & 6 were a lot darker than the rest so they’re going to be replaced. However after putting everything back in the order I took them off I’m now getting codes for bank 1 rich at idle (P2188). Before its said I am 100% confident that both the sparks and coils where returned to original placing just getting more lost now than when I started.