M30b35 E30...

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Minstrel
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Post Fri Jun 15, 2012 5:52 pm

My M30 E30 seems to sometimes run but as soon as you drive down the road it will then cut strait out!?

Sometimes it won't start at all???

Any ideas? Need help!!!

Thanks![/list]
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zaust
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Post Fri Jun 15, 2012 8:43 pm

That's a bit vague. More discription.
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Minstrel
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Post Fri Jun 15, 2012 11:24 pm

I've now checked at found out I haven't got a spark anymore, and I swapped the coil over and it's still the same. Would a dizzy cap and rotor arm cause my car to just cut out when driving? Or be intermittent?
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Das_BMW_E30
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Post Fri Jun 15, 2012 11:25 pm

Yes
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Minstrel
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Post Fri Jun 15, 2012 11:31 pm

Ok cool, cheers
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cecotto479
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Post Sat Jun 16, 2012 9:02 am

Minstrel wrote:I've now checked at found out I haven't got a spark anymore, and I swapped the coil over and it's still the same. Would a dizzy cap and rotor arm cause my car to just cut out when driving? Or be intermittent?
It could do, but "Yes" as an answer is just pointless.

Remove the lead from the coil to the distributor cap at the distributor cap end. Place it close to but not touching a good earth. Crank the car over. You should get a good fat spark between the lead and the earth. If there's a spark, look inside the cap. If it hasn't been changed in a while a new cap and arm won't go wrong anyway.

If there's no spark your problem lies before the distributor cap.
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Andyboy
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Post Sat Jun 16, 2012 12:50 pm

It really depends of what Motronic system it has. If the engine came from an E28 and it has the two TDC sensors on the bellhousing, I'd be looking at the DME relay, a fat 7 pin job.
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cecotto479
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Post Sat Jun 16, 2012 2:03 pm

Were all B35s not later with the toothed wheel sensors?
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cecotto479
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Post Sat Jun 16, 2012 2:03 pm

Were all B35s not later with the toothed wheel sensors?
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Andyboy
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Post Sat Jun 16, 2012 3:51 pm

B35's were yes (E34, E32 etc) but the old E28/E24 units had the two sensor set up.
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cecotto479
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Post Sat Jun 16, 2012 5:18 pm

They were the B34, though weren't they. The heading suggests we're dealing with a b35 which is why I asked.
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Andyboy
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Post Sat Jun 16, 2012 5:34 pm

So it does! :o:
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Minstrel
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Post Sat Jun 16, 2012 8:59 pm

My m30b35 is from a 88 e34 5 series, has a single TDC sensor
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Brianmoooore
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Post Sat Jun 16, 2012 9:17 pm

Minstrel wrote:I've now checked at found out I haven't got a spark anymore,
How about the fuel pump? Does that run when you crank it?
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Minstrel
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Post Sun Jun 17, 2012 2:21 pm

Fuel pump works, it's getting fuel.
Changed the coil,
King lead,
Cap and rotor....
And still no spark!!!???
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Brianmoooore
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Post Sun Jun 17, 2012 2:56 pm

If you're 100% certain the fuel pump runs when you crank the engine, there's not a lot left to check. Are you sure there's 12 volts at the coil + terminal all of the time? That really only leaves the ECU and one off wiring faults.
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