Twin turbo difficult to start

E

eng622

New member
Posted about this a few weeks ago and had one response suggesting a fuel issue. It seemed to be how I started it and the start button. Some times I had to release the brake pedal to get it to start. The fault went away after pressing the start button more firmly and was fine for a few weeks starting instantly. But on a recent long journey needed to accelerate up a hill and the yellow half engine light came on, the engine was very lumpy for a few miles but then ok but with much less power. On return started ok but light came on again after some miles but was able to cruise on the motorway at 70 mph.
Next day back to difficult starting taking several seconds of cranking and needing to release the brake pedal. Engine very lumpy and poor idle for a few seconds and then the small yellow engine light came and on driving away the larger half engine light came on as well. But now it is difficult to start when hot which has never happened in the past. The small light wont go off but the half light does.
Thinking I have an intermittent fault that may now be permanent. Ordered an OBD scanner any clues on what might have failed.
 
Need fault code reader..my guess failing / failed fuel injectors…maybe HPFP maybe LPFP..but injectors my bet..

Did I say fault code reader ?
 
Bought a scanner and get two codes. Both P3049. First ends $07e8, second $07e8Pd.
Still difficult to start, only seems to want to start on releasing the start button.
 
eng622 said:
Bought a Foseal FO-01 wired one, are you saying these are no good. Had good reviews.
Click to expand...

Yup it’s crap…

You need a decent code reader that supports BMW extended code support..a rudimentary thing like that is almost worse than useless…

Even with a decent BMW code reader it’s not as easy as you would wish for..

Tough love required some times…
 
Found a list of codes and P3049 gives activation starter relay open circuit. Is this relevant to difficult starting.
Also there was a safety recall about installing repair cable for positive battery terminal line, which I never had done but now booked in.
Could this be part of the problem. As said only wants to start on releasing the starter button suggesting to me it may be a power problem.
 
The problem is p3049 is a generic code being returned by the basic code reader - it's not going to pinpoint the issue for you. If anything it will lead you down the path of wasted money & misinformation. Return it if you can, and get the fiver back.

You really do need to spend the £60 or so on a code reader that can give the BMW specific codes - that really narrows down the problem.

Nobody here (or anywhere else on the tinternet) can help other than make good guesses without that information.

£60 is cheaper than a single garage visit - money well spent.
 
OK did not realise the cost of getting a mechanic to do it. The reader does say it is a manufacturers code not a generic one.
 
The answer you need is as above - a code reader that is up to the job. Examples of such are in this thread, without one you are up the creek without a paddle.

Most garages charge £100 (or something in that region) for diagnostics - you might get lucky & it cost less wherever you live.

If you own this e89, you are going to want that good code reader several times - it's considered a 'must have', especially if you want to try to fix things for yourself rather than rely on BMW.

That's another thought - BMW garage will sort this out for you, but expect to pay a few hundred for the privelige of them even telling you what is wrong.
 
Professional scanner codes results
0029F2 - high pressure fuel system
002FBF - fuel pressure on release of injection
Also a code on low battery voltage which was not thought relevant but maybe it is. I'm thinking the problem may well be electrical.
This is what happened next. Codes were erased but while idling the EML came on and when I drove off the half eng light. Mechanic started the car and did note it took several cranks to start Only 1/4 mile back home. Switched off and restarted. EML on and quickly the half light came on and the engine went into very rough idle backfired in the exhaust badly on revving up and then would not idle just stalled. Tried numerous times and would not idle for more than a few seconds. So looks as if it will not go anywhere as DCT.
So plugged in my scanner and got 3 new codes saying random/multiple misfire and misfire on cyl 3 & 4. Not surprised by this result as car looks like it will not drive anywhere.
Now I erased the codes and the car started quickly idled at 700 rpm and very smooth. Revved up gently to 1500 rpm and no lights came on but did not road test as worried about stalling.
I'm reading that the misfires were due to lack of fuel and it is the HPFP that is not delivering correct amount but may not be the pump.
Mechanic said first to check the fuel filter but these are said to be for life (car only done 40K miles) and with the pump/filter in the tank a difficult job.
So think should measure LPFP pressure.
The fault does look intermittent and could be electrical. Where is the pump connector located.
Also could be the positive battery terminal lead which is a recall, not done but booked in for Thursday if I can get the car there.
T
 
You don't mention the age of the car?

The z4 is super sensitive to degraded battery, which presents as all manner of issues which are actually not issues atall - but the battery is the problem.

If the battery is over 5 years old, I would start there & get it replaced.

Then see if your other issues dissappear.

HPFP is a common failure on these cars, I would be thinking on that direction TBH if still a problem with a known good battery.

If your car is a 2009/2010 35i then there was a recall for this in the US, and the HPFP was replaced. Not sure if valid inthe UK.
 
The car is 2009. Checked if HPFP has extended warranty and it does but limited to 10 years old so no good for me.
The battery is the original as far as I know, purchased when 3 years old. I had the battery tested and said to be good. The engine spins over with ease so cannot see it is at fault. But other connections could get lower voltage when cranking due to high resistance which could be the difficult start problem/fuel starvation if that is the problem. Hoping to get the recall cable done this Thursday only a few miles drive to Sytner Nottingham. If it stalls on route is there anyway to get it moving with DCT or will I have to call breakdown.
 
If it’s a 2009 battery then it should be replaced as a matter of course…there are quite a few faults created by aged batteries on E89s despite their ability to spin the engine..

DCT will set itself to Park whrn engine stops..

It’s possible to move from Park to Neutral buts it not a owner based task..so it’s a lift recovery if it can’t start

Looks like given your lack of skills and knowledge that you just let Synters sort it out and suck up the bill..
 
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