M30b34 conversion won't idle

[matthewp]

I have investigated Autronic (expensive, requires mods but good), Haltech(mid range, simplest to fit), Wolf(dubious support and provenance).

What brand would you suggest? Do you have one in your car?

At the moment I want to fully eliminate all possible reasons why it doesn't work with the original gear. After all, there's still plenty of engines working that way.

i am running an autronic. very happy with it. I was easy to install and inexpensive( second hand on ebay).I use to run a haltech but it was an earlier batch fired one. I have a m30b34 from an E32. I had to use an older 2 pin idle control of a Falcon(bosch). I'm running a 292 deg cam had the head flowed, oversized valves etc. Nice cold start, idles at 1000.

 

[millisk]

i am running an autronic. very happy with it. I was easy to install and inexpensive( second hand on ebay).I use to run a haltech but it was an earlier batch fired one. I have a m30b34 from an E32. I had to use an older 2 pin idle control of a Falcon(bosch). I'm running a 292 deg cam had the head flowed, oversized valves etc. Nice cold start, idles at 1000.

Hi Matthew, thanks for that information.
In the event that I have no success with the original setup, I would be interested in getting the details of the Autronic unit that you are using. Model#, Bosch idle control and installation tips. Advice given to me was that mods had to be done to the motronic distributor, a new flywheel sensor, and a separate Bosch ignition module as well.
I spoke to the inventor and owner of Autronic, Richard Aubert, last year.

 

[millisk]

I think you need to double check your reference to the 714 injector- that is a high impedance injector that wasn't in use when your car was produced.
I believe early motronic used the 201 injectors as did later m cars.

Recheck your coil voltages with the - wire disconnected.
Your voltage readings are off by a huge amount.

Injector spec reference
http://www.malloc.nl/BMW/635CSi/pages/en/13000000.html#refertoc

Rechecking coil voltages today.
Other posts noted.

 

[matthewp]

Hi Matthew, thanks for that information.
In the event that I have no success with the original setup, I would be interested in getting the details of the Autronic unit that you are using. Model#, Bosch idle control and installation tips. Advice given to me was that mods had to be done to the motronic distributor, a new flywheel sensor, and a separate Bosch ignition module as well.
I spoke to the inventor and owner of Autronic, Richard Aubert, last year.

my pickup is on the harmonic balancer 60-2 factory set up.
ignition module is a bosch. wreckers or ebay.
No mods to the distributor.
you will need to use autronics manifold air temp sensor. around $120.
Richard is a good guy, very helpful so to is Ian who will be your contact for getting a base map.

 

[millisk]

Don,
update on actions:
1. Coil test with -ve wire disconnected. +ve 12.27v, -ve 12.27v, HT 12.27v. Battery voltage = 12.45v
2. No voltage dropping resistor in circuit.
3. Pics of valve timing. Slight parallax on crank mark image, but is on the mark.
4. Timing chain replacement spec. Image M30b24e.jpg
http://www.malloc.nl/BMW/635CSi/pages/en/11310510.html#refertoc
5. Spark plugs all sooty black. Not wet.

 

[Bert Poliakoff]

AFM 013
ECU 002
Are correct. Your engine is running 1st year of Motronic. Motor had to come from a car built from May of 81 to the model year change in May of 82... This was a one year production and wiring harness etc are unique to the last year of the M90. You will also find the last year M90 does not have raised water passages on the drivers side as on the pre 81 euros.

 

[sfdon]

So no doubt your black wire to coil ve- is a problem.
Sounds like You are getting a tiny weak spark giving you black plugs.
Run a resistance test between black wire ve- and ground with ecu disconnected.
Should be infinite resistance.
If you connected that wire to your tach- disconnect it before testing.
In fact- retest voltage with tach disconnected and ve- reconnected.

Don

 

[millisk]

So no doubt your black wire to coil ve- is a problem.
Sounds like You are getting a tiny weak spark giving you black plugs.
Run a resistance test between black wire ve- and ground with ecu disconnected.
Should be infinite resistance.
If you connected that wire to your tach- disconnect it before testing.
In fact- retest voltage with tach disconnected and ve- reconnected.

Don

Thanks Don! The tach isn't working at all so could be the cause?
I will test as instructed and let you know.

 

[millisk]

AFM 013
ECU 002
Are correct. Your engine is running 1st year of Motronic. Motor had to come from a car built from May of 81 to the model year change in May of 82... This was a one year production and wiring harness etc are unique to the last year of the M90. You will also find the last year M90 does not have raised water passages on the drivers side as on the pre 81 euros.

Hi Bert
the e24 donor car's serial # is 5550551 and it was produced in 09/1980 with a Type Code of 5332. Real OEM has it listed. I have sourced the same AFM and ECU, along with wiring harnesses and other engine from a 7 series, e23, in the same era.
Ken

 

[millisk]

So no doubt your black wire to coil ve- is a problem.
Sounds like You are getting a tiny weak spark giving you black plugs.
Run a resistance test between black wire ve- and ground with ecu disconnected.
Should be infinite resistance.
If you connected that wire to your tach- disconnect it before testing.
In fact- retest voltage with tach disconnected and ve- reconnected.

Don

Don, you've had a success! Sure enough there is a fault in the -ve line to the tach, or in the tach itself. (Nice job to remove). When I ran the car with the black tach wire disconnected it idled steadily with a smooth transition from and to the idle circuit.
Now just have to set the AFM arm at 3000rpm and CO levels at idle and eliminate air from the cooling system causing overheating.
Thank you for your expertise and assistance.
Ken

 

[sfdon]

 

[sfdon]

Which tstat housing do you have?

 

[Stevehose]

There goes your Australia trip!

 

[sfdon]

I'm my own worst enemy...

 

[millisk]

Listing on Real OEM

Http://www.realoem.com/bmw/enUS/par...5CSi&mg=11&sg=35&diagId=11_0708&q=11531710959

Bought a new one for engine rebuild in 2014. Cost AUD$118.
All 4 tapped holes are utilized.
Bled coolant today. No more overheating.
Finally, after x months I can drive it.
Cheers to you, Don!

 

[sfdon]

Enjoy! Glad it all worked out.