Pre facelift 325i with Motronic 1.1

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Post Sun Feb 05, 2012 10:39 am

No spark at the plugs.

Did I read somewhere that a spark check direct from the coil won't work unless the coil primary negative is grounded?

Given that the distributor cap and rotor are relatively new, I figure that no spark at the plug WILL mean no spark at the coil, therefore, I'm off to check the two crank position sensors and to see if the pin has come out of the flywheel.

Also, does a missing pin/faulty CPS stop the fuel pump.

Cheers,

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Post Sun Feb 05, 2012 10:50 am

If the CPS doesn't work, then there'll be no spark or fuel pump.

Just because the dizzy and cap are new doesn't mean they'll be ok, but you can check for spark at the coil just by connecting the king lead to a spark plug, and grounding the plug to the engine block/head/rocker cover.

If there's no spark, but the fuel pump is working and the ICV is buzzing, then your CPS is working.

For more info on this, the Wiki is a mine of info:

http://www.e30zone.net/e30zonewiki/inde ... Management

http://www.e30zone.net/e30zonewiki/index.php/Ignition
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Post Sun Feb 05, 2012 8:01 pm

before doing anything check for 12V at the coil.

neg indeed discharges the coil, be careful !!!
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Post Mon Feb 06, 2012 1:50 am

Ant wrote:before doing anything check for 12V at the coil.
Yes, yes there's 12v at the coil +ve
Ant wrote:neg indeed discharges the coil, be careful !!!
Meaning that if the neg is discharging through the ECU a coil spark test wont work?
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Post Sat Feb 11, 2012 7:02 pm

Got as far as taking the inspection cover off before it got too cold and too dark to carry on.

Here's my plan for the morning. Have I got all the stuff I've gleaned from various threads correct?

First, as I didn't previously do this (!), bridge 3 pins, 30-87-87 on main relay (the one with 5 pins) to rule out relay failure. (BTW, does this mean take out the relay and connect up the three holes marked with those numbers?)

Relay OK - Check for pin on flywheel.

No pin ”“ stock take re Motronic 1.3 upgrade. (I already have a load of later 325i engine bits).

Pin present, check for 1000 or so ohms across two of the pins of each position sensor. Two sensors should match.

Sensors OK ”“ check that fuel pump can be heard operating when cranking.

Fuel pump activity - ECU must be OK - WHAT IS WRONG WITH MY CAR?

No Fuel pump activity ”“ Suspect ECU or ECU supply.

How do i go about checking ECU supply?

Thanks

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Post Sat Feb 11, 2012 7:09 pm

You're right with your steps so far. If you want a really quick test, do this:

Connect a wire from the battery + to Coil pin 15 (green wire).

Bridge the main relay (yep, connect those three holes together).

Do the same with the fuel pump relay (holes 30 and 87)

Now try starting it with the key. If it doesn't work, then one of the critical engine components has failed (spark plug, injector, air leak etc). If it does work, let us know and we can troubleshoot further.
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Post Sun Feb 12, 2012 5:31 pm

How the hell is one supposed to tell if the flywheel pin is in position without taking the box off? Best I could manage was holding an allen key over the gear ring and feeling for it whilst my intended cranked the starter. Did seem that the pin was in place.

However one of the sensors on the bellhousing (it's pre-facelift remember) has no continuity across any of the pins. So that would appear to be the problem.

Two questions - does anyone know how to get the thing out without taking the box off and hammering from the inside. (I have already removed the screw and the thing does not want to budge.) Unfortunately its the position sensor so it sits behind and slightly obscured by the gear ring - just cant get the access to lever the thing out. Any tips greatly received.

Second, are they as pricey as real OEM seems to suggest - 70 Euros - come in pairs? I'd really rather just change the sensor, not the ECU, loom, cam belt cover, pulley etc etc.
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Post Sun Feb 12, 2012 7:30 pm

There is a bit you can remove from the back of the sump that allows you to see the flywheel so you can check the pins.

As for removing the sensor, everyone says they just pullout but i found mine impossible to remove without smashing it to bits. I then took the decision to convert to M1.3. That was quicker than removing the sensor!

Yes they are pretty expensive and the price is for a single sensor, think they are identical anyway.
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Post Sun Feb 12, 2012 8:16 pm

Kedge wrote:There is a bit you can remove from the back of the sump that allows you to see the flywheel so you can check the pins.
Yes, I've got the hatch off - great view of the engine side of the flywheel, but precisely no view of the g/box side where the pin is.
Kedge wrote:As for removing the sensor, everyone says they just pullout but i found mine impossible to remove without smashing it to bits. I then took the decision to convert to M1.3. That was quicker than removing the sensor!

Yes they are pretty expensive and the price is for a single sensor, think they are identical anyway.
Hmm. I can see where this is going. I have already got a later version sensor, so if I can get the old one out and the other one works that will be preferable.

Does anyone reckon that the Motronic 1.3 will make an appreciable difference to the drive?
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Post Sun Feb 12, 2012 8:33 pm

Kedge pretty much wrote the book on converting to Motronic 1.3

http://www.e30zone.net/e30zonewiki/inde ... 3#Benefits

Although with 2 sensors, it sounds like you have Motronic 1.0 fitted instead of 1.1...
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Post Sun Feb 12, 2012 8:55 pm

Grrrmachine wrote:Kedge pretty much wrote the book on converting to Motronic 1.3

http://www.e30zone.net/e30zonewiki/inde ... 3#Benefits

Although with 2 sensors, it sounds like you have Motronic 1.0 fitted instead of 1.1...
Indeed, I was confusing 1.0 and 1.1.

That Wiki page does not mention a new ECU except in the case of upgrading from 1.1. I presume that it assumes that your new loom has the right ECU attached to it. I wouldn't be using my existing ECU would I?
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Post Sun Feb 12, 2012 9:03 pm

FEP wrote:
Kedge wrote:There is a bit you can remove from the back of the sump that allows you to see the flywheel so you can check the pins.
Yes, I've got the hatch off - great view of the engine side of the flywheel, but precisely no view of the g/box side where the pin is.
Can't you get your fingers in there and feel for them? Been a while since i've done this.
FEP wrote:Hmm. I can see where this is going. I have already got a later version sensor, so if I can get the old one out and the other one works that will be preferable.

Does anyone reckon that the Motronic 1.3 will make an appreciable difference to the drive?
The later version sensor from a M1.3 won't work with your current management system, which as Rich says is infact M1.0. As far as i understand (i'm yet to actually drive mine since the swap :( ) it won't be noticeable change in how it drives but it is more reliable, spares are more readily available, it's cleverer from a diagnositic point of view and monitoring how the engine runs. M1.3 can also be chipped or remapped.
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Post Sun Feb 12, 2012 9:05 pm

FEP wrote:
Grrrmachine wrote:Kedge pretty much wrote the book on converting to Motronic 1.3

http://www.e30zone.net/e30zonewiki/inde ... 3#Benefits

Although with 2 sensors, it sounds like you have Motronic 1.0 fitted instead of 1.1...
Indeed, I was confusing 1.0 and 1.1.

That Wiki page does not mention a new ECU except in the case of upgrading from 1.1. I presume that it assumes that your new loom has the right ECU attached to it. I wouldn't be using my existing ECU would I?
Will update the Wiki to make that clearer then, but yes you won't be using your existing ECU, the plug is totally different.
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Post Sun Feb 12, 2012 10:39 pm

Thanks.

Shame about the sensor. Gonna have to weigh up the costs and bother of just doing a sensor change, versus 1.3 upgrade.

Anyone got a 1.3 loom and ECU for sale?
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Post Sun Feb 12, 2012 10:51 pm

Pretty sure I have everything for a M1.0 to M1.3 swap apart from the ignition lead with the CIP lead on it if you're interested. Will probably cost more then buying a new sensor but from my experience it was easier to do the swap than removing the flywheel sensor after my experience, i couldn't even get the replacement sensor to fit back into the bellhousing :mad:
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Post Sun Feb 12, 2012 11:53 pm

Kedge wrote:Pretty sure I have everything for a M1.0 to M1.3 swap apart from the ignition lead with the CIP lead on it if you're interested. Will probably cost more then buying a new sensor but from my experience it was easier to do the swap than removing the flywheel sensor after my experience, i couldn't even get the replacement sensor to fit back into the bellhousing :mad:
OK - thanks. I guess I'll see how I get on getting it out and once I've exhausted my supply of expletives, I'll get back to you.

Pretty sure that I've already got the toothed pulley, lower timing belt cover with bracket, oil level and pressure sensors and CPS. How much for loom and ECU and anything else I've forgotten?