Twin turbo difficult to start

eng622 · Post by **eng622** » Sat Sep 30, 2023 9:48 pm

If that is the case not good enough. It is a long cable from the battery to the fuse box. Not likely to be the cable but the connectors at each end, the fuse box end may be the worst. Will never know as have not dropped the fuse box to inspect.
Said to be a 2hr job. Health check done by 12.30, car ready at 3.00 and valeted which must have took 30 min. as so clean so that leaves 2hr so maybe they did do something.

matsmith749 · Post by **matsmith749** » Mon Oct 02, 2023 9:35 am

These questions would have been best asked whilst at the BMW dealership that did the work - they would have been able to tell you the answers rather than us guess.

Just saying.

Baza · Post by **Baza** » Tue Oct 03, 2023 1:21 pm

Hi Just read your initial post re difficult to start. I had what seems to be the same issue with my E89 3.0i 2009 I had to depress the start button for a long time and it would only seem to start after lifting my foot or the brake pedal . I took it to my local Indy who after checking codes came back with the camshaft sensor being faulty after changing one sensor it seemed ok but then started again fortunately it was still with them so they changed the other. Since then it has started as should and is fine.

Not saying this is your problem just that your symptoms are a lot like mine were.

matsmith749 · Post by **matsmith749** » Thu Oct 12, 2023 9:43 am

Fixed?

eng622 · Post by **eng622** » Tue Oct 31, 2023 6:36 pm

Been away a while. New battery fitted today by a mechanic. Charged the old battery, started straight away, drove less than half a mile no waning lights ran smooth. With new battery lots of cranking, warning lights, stalled but got home, ran rough then normal and repeating that. Booked in for fuel pressure tests. Mechanic thinks it could be a blockage maybe the filter but only done 40k. Does seem to be intermittent so thinking it could be an electrical connection. Any further ideas.

matsmith749 · Post by **matsmith749** » Wed Nov 01, 2023 10:08 am

My honest & open recommendation is to take this to somewhere that understands this engine & get it sorted there.

A general purpose mechanic is guessing, a decent BMW independent will figure this out quicker & cheaper in the long run.

Wish you luck

eng622 · Post by **eng622** » Thu Nov 02, 2023 7:00 pm

Indies are in centre of Nottingham, not confident it will get there. As said lurches forward and then hesitates on return of batt fitment. Idle erratic and will stall and on blipping throttle misfires in the exhaust. Done only 10 miles since MOT when emissions were very low.
Read this. With the half engine light on (limp mode) the HPFP is switched off. Fuel is fed to the rail by the LPFP, correct fuel mixture and normal running, and no difficulty in starting. It is said in 99% of cases when you get code 29F2 (high pressure fuel system fuel pressure) which I get, the fault is the LPFP pressure or leaking injectors. Exhaust misfires are caused by too much fuel (leaking injectors?) or not enough (low pressure or blockage). It cannot think it has leaking injectors as would have failed MOT on emissions?. It is said to check the pressure valve on the HPFP as they can mechanically jam.
I did let the fuel run low, less than 10 miles, some time ago. The fuel filter has never been cleaned or changed as in the tank and said to be good for 100K miles, have done only 40K. Read 40K may be the limit though.
Local mechanic is going to measure the low and rail pressure but guess if in limp mode will not indicate anything about the HPFP.

matsmith749 · Post by **matsmith749** » Fri Nov 03, 2023 1:15 pm

Is having it trailered to the place that can actually diagnose & fix it not an option?

Chippie · Post by **Chippie** » Fri Nov 03, 2023 6:11 pm

are you capable of removing the spark plugs, if so I’d suggest turning the ignition on in the evening but not starting the car, then the following morning remove the spark plugs and see if any are wet or smell of petrol, if so that would indicate at least one leaking injector.

eng622 · Post by **eng622** » Fri Nov 03, 2023 8:08 pm

Actually diagnose and fix the problem? How do I know indies are any good. Owners on this and other forums have spent £1000's on this problem, many without success. Not capable of removing spark plugs. If it sometimes starts quickly and runs ok for even a short time why would it be the injectors. If they leak they leak cannot see they can be intermittent.
I got rid of a Merc 350sl because that was riddled with faults and a BMW Mini with the Prince engine, low mileage but a heap of crap engine drinking oil. Bought the Z4 when 3 years old, perhaps I should get rid as these cars look just as bad and would never had bought if had known the potential problems. A money pit, for example Sytner wanted £150 (I guess + vat) just to OBD the faults. The mechanic I used did this for free.

matsmith749 · Post by **matsmith749** » Sat Nov 04, 2023 1:59 pm

& there you go.

Is there a common pattern to the cars YOU have had?

Modern cars are a pain in the ass to be fair, way too complex, too many electronics, too overtuned for performance etc etc. I get it.

But diagnosing & fixing a modern car (any of them) needs lots of kit, lots of prior knowledge of the marque, a modicum of skill.

They are DIYable to an extent if you have the gear, skills, space, time, patience etc - but some of us (me included) don't & have to trust the dealerships / indies at least a little.

eng622 · Post by **eng622** » Mon Nov 13, 2023 8:51 pm

Took car to an indie and they say HPFP pressure is low. Pump from BMW around £1000 and 3HR to fit. They want to check the fuel rails to make sure no debris getting into injectors before fitting a replacement. They only want to fit one sourced from BMW, I'm ok with that but read they are not new but remanufactured so have some concern about warranty/how long it will last before going ahead.

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