Manual conversion starting issues

[Surge 1]

Just put a manual in place of the automagic on my 86 325i (and a new motor) and can't get the thing to start up for the life of me. No fuel or spark so leaning towards poked ECU/relay or lacking required signal inputs. The auto box had 2 connectors which connected below the intake manifold which remain unplugged, on all the conversion info I've seen on the net dealing with these plugs is not required (or mentioned). I've heard some Getrag 260s have sensors on the bellhousing for that rely on outputs from the flywheel. My gearbox does not have these. Where does an early m20 get the crank position signal from? I have one sensor at the front of the motor clipped in but not sure as to whether that's it.

[polley 916]

The older E30's used sensors in the bell housing that read off the flywheel to tell posistion of the crank for the ECU. You need a older gearbox with the holes for these sensors and the correct flywheel.

Or convert it over to the newer motronic ECU with sensors on the front of engine.

You need:

ECU

Loom

Crank sensor + bracket

Front pulley / dampner (toothed wheel)

Thats all I can remember right now... been a long time. Hopefully some one else will know what other parts you need.

[BM WORLD 1260]

what he said , it nots going to start without the proper cranking signals from teh flywheel sensors etc.

you can drill out the holes in the gearbox if you know what you are doing , has to be just in the right place.

also you can weld on a crank reference marker to the flywheel if you know what you are doing .

i know where there is a g260 from a early 325i with the holes in it for the sesnors .

but maybe convert to the later e30 motoronic system

front hub , ecu , engine loom complete etc

[Jono51 57]

Just put a manual in place of the automagic on my 86 325i (and a new motor) and can't get the thing to start up for the life of me. No fuel or spark so leaning towards poked ECU/relay or lacking required signal inputs. The auto box had 2 connectors which connected below the intake manifold which remain unplugged, on all the conversion info I've seen on the net dealing with these plugs is not required (or mentioned). I've heard some Getrag 260s have sensors on the bellhousing for that rely on outputs from the flywheel. My gearbox does not have these. Where does an early m20 get the crank position signal from? I have one sensor at the front of the motor clipped in but not sure as to whether that's it.

give me a call,

I have a way around this

cheers

Jon

[Surge 1]

Established well and proper that the issues above were the ones you all raised. Converting to motronic 1.3 now.

I've got the loom off a fl-320i, sourcing the ECU now..

Few Q's: Is the O2 sensor required? (for 1.3) Will an pre-facelift TPS and airflow meter work? (they do plug in)

Cheers guys.

[barf 0]

BMW used switch type throttle position sensors until the introduction of the M50. almost any switch-type TPS should work.

the EFI control systems started with the Telefunken distributor-less firing the coil thru the dizzy (when dizzy found on passenger side), they moved onto 60-2 trigger wheel systems later and about the same time the dizzy was relocated to the front of the cam. some production resulted in 60-2 sensors in the bellhousing and later the trigger-wheel was put onto the crank pulley.

in my case it was easier to just change the front crank pulley with a late-model M20 one which has the same sensor in a much easier-to-service location.

O2 sensor is not required, except to satisfy a complete system. they're next-to-useless narrowband types anyway. not sure about AFMs, get an MS2 and go MAP sensor for better throttle response :-)

[Surge 1]

Excellent, cheers dude. I'll just test the AFM when I get the ECU I guess, unless anyone knows 100% that it's different. Agree about the crank sensor being on the front of the motor... Much easier. Does 1.3 just rely on that (+the spark lead sensor) I notice my old auto has 2 sensors in the bellhousing.

Link or MS will be installed when cash starts flowing again... I'm a big fan of replacing old electronics!

[BM WORLD 1260]

Established well and proper that the issues above were the ones you all raised. Converting to motronic 1.3 now.

I've got the loom off a fl-320i, sourcing the ECU now..

Few Q's: Is the O2 sensor required? (for 1.3) Will an pre-facelift TPS and airflow meter work? (they do plug in)

Cheers guys.

i have a ecu if you need

021433600

[skidz 196]

Excellent, cheers dude. I'll just test the AFM when I get the ECU I guess, unless anyone knows 100% that it's different.

If you got the 320i ECU, these are the same as the 325, only the chip being different (different fuel map etc) So you could use the 320 ecu with an afternmarket chip...

[polley 916]

I can send you a 325i chip to put in. (tuned JC chip)

Edited September 8, 2011 by polley

[barf 0]

Excellent, cheers dude. I'll just test the AFM when I get the ECU I guess, unless anyone knows 100% that it's different. Agree about the crank sensor being on the front of the motor... Much easier. Does 1.3 just rely on that (+the spark lead sensor) I notice my old auto has 2 sensors in the bellhousing.

Link or MS will be installed when cash starts flowing again... I'm a big fan of replacing old electronics!

AFAIK the only timing source the ECU needs is the 60-2 trigger wheel. i believe the spark lead sensor is an inductive pickup which is only wired to the diagnosic connector for timing lights.

in my experience the best thing to do with a BMW engine management system is replace it (you can't polish a turd). although if these chips are just 27C-family EEPROMs, they only cost $8 - $16 which could be a cheap fix :-)

[polley 916]

in my experience the best thing to do with a BMW engine management system is replace it (you can't polish a turd). although if these chips are just 27C-family EEPROMs, they only cost $8 - $16 which could be a cheap fix :-)

They are 27C~.

I dont see why you call BMW engine management a turd.

[barf 0]

They are 27C~.

I dont see why you call BMW engine management a turd.

mainly because it's an old design, with limited capabilities and resolution. to be fair, cars havn't changed as much as electronics have but even at the time Japanese cars had superior electric systems. Toyota were doing electronic spark advance as early as 1979. AFAIK the M20 didn't see this until 1987. Edited September 9, 2011 by barf

[polley 916]

mainly because it's an old design, with limited capabilities and resolution. to be fair, cars havn't changed as much as electronics have but even at the time Japanese cars had superior electric systems. Toyota were doing electronic spark advance as early as 1979. AFAIK the M20 didn't see this until 1987.

Yeah, I agree that motronic 1.3 may be a bit primitive but it gets the job done. However people have managed amazing things on stock management on newer BMW engines, even older engines like M50's people have done cool things with the ECU's... 600-700hp and anti-lag just by rechipping.

[Surge 1]

All up and running now on the Motronic 1.3 (cheers Jon for the ECU + Motor) - was a relatively easy conversion. Running the pre-fl AFM with no noticeable issues. The only thing on the new loom that had to be done was cut the ring terminal off the starter wire and convert it to a spade terminal (to suit the older starter motor) and change the oil level sensor for a facelift one.

I removed the notorious plug below the intake manifold (the one that goes to the injectors + temp sensors) and hardwired it - apparently these plugs can cause all sorts of problems over time with water getting into them.

Tach wire came off c101 engine side to c104 under the drivers side - black wire (ran a wire from the plug to under the dash, a more elegant solution would be to pull the wire thru near the computer and cut off half the legnth). Other than that the c101 plugged straight across less a few unneeded things.

Drives good now going from a 325i auto with an extremely worn cam resulting in an engine that never idled without massive vibrations to a 325i manual. I replaced all shift linkage parts with new items and put new fluid in the box, it makes a huge difference to the shifts - nice and easy with no slop. I used a solid clutch line (no factory rubber near the slave cylinder) instead of the factory item - makes the clutch much more responsive than other e30's I've been in - all at a cost of $22.00 for the line with fittings, which you can bend yourself.

[tire 10]

Sounds great, well done Surge.