M42 w/ DASC hard start mystery ?
 

Sorting out this new to me m42 w/DASC... I've had this looked at by the local BMW specialist and he's unsure but he also is unfamiliar with the DASC set up.

When starting the car, it takes two or three tries to start. It's consistent, maybe once it started on the first try when relatively warm but still had to crank a bit. The odd thing is the motor stops turning over completely after the first two cranks, with the key still in the crank position. Then key off, then crank position, cranks two or three times, then stops completely. Key off, then cranks a few times and starts up perfectly and immediately settles into idle.

I'm not sure about the fuel pressure, haven't hooked a gauge up but the car does have the RFPR (and I'm not sure of the setting, seems comparable to some threads I've searched).

Car pulls hard, doesn't seem limited by fuel, doesn't seem to be running lean or rich.

The only thing I've found is that the + terminal was a bit loose but after tightening symptom is still there.

The 'seizing' is a bit worrying, but when it does start it seems fine.

Thoughts?

Thanks ~

Dont worry too much about the RRFPR as at start and idle it will be at 35 psi (standard). Did it do it only after you fitted the DASC? Dont think this problem would have anything to do with the DASC, unless when cranking it it is spluttering?

Does the motor stop like a compression lock like it is trying to compress a liquid or the starter is loosing power?

This is what needs to be known before I can help you any further.

John S

Yes, it's exactly like a compression lock. Is there any way to visually check for non-original headgasket? Would a higher cranking battery make a difference?

Thanks ~

Had somewhat similar problem with my m44 DASC, with the exception of this (stops turning over completely after the first two cranks) I replaced OEm BMW battery with a better, much higher CCA battery, went from 540 on bmw to 700 on autozone battery, this helped, even though the old bmw battery tests good, and has green indicator on for everythign is good.

Also i played with the throttle cable a little, unscrewed it just enoguh where it didnt raise idle at all if any, but was more consistent now, i also had a slight idle problem where once in a while it would be a roguh idel sporratically once in a while for a split second or two, liek the engine was about to die, in fact sometimes it died on me.

i think for me it was a combination of things but thats what fixed it. When i had the start problem i wanted to check the fuel pump to see if i am getting enoguh pressure to start engine, so i tuned the key to position 2, in whcih you clearly hear the fuel pump go on, i did this twice or three times to where it would not do it agian, and it always started fine, but if i did not do this it would not want to start just like you describe, it pissed me off and i started with new battery whcih helped but wasnt 100% perfect, so then i went to throttle cable.

Still trying to figure this out, really confused by the way the starter is stopping turning after cranking... if I keep the key in the start position it will pause for a few seconds then try again... man it's really a bitch to reach the starter underneath the DASC! Usually starts 3rd or 4th try.

Finally got this sorted, despite my starter having tested okay it turned out to be the starter after all. Replaced and all is well. Thanks for all the input. :rolleyes: