A quick question for the Motronic experts...

[genphreak]

If you disconnect the pulse generator from Number 6 cylinder wire, what happens?

I accidentally left it disconnected and noticed the car running rich a little while after that. However it seems to have sorted itself out after a bit of driving.

http://www.realoem.com/bmw/showparts...49&hg=12&fg=05
09PULSE GENERATOR
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Anyway, I tried connecting it again and the car didn't even want to start. It did after 30secs cranking but then ran like it was on 4 cylinders (except at idle where it ran at 1200rpm instead of the usual 750) I could also smell that it was burning way too much fuel. Disconnected the sensor and it started fine as if nothing had happened.

So now I am running with it disconnected. I might try doing a shogun reset and then try reconnecting it again.

It seems to run fine as it is though, no alerts, nothing weird. and it really hammers... What is the pulse generator for, does anyone know?

Cheers, Nick

[Jeff N.]

The pulse generator triggers the batch fire sequence for the fuel injectors.

The Motronic 1.3 on the BMW is setup to fire the injectors in two timed batches of three each. This is to more closely align the injector pulses with the valve track. The pulse generator is the trigger for timing the sequence.

If the pulse generator is disconnected the injectors fire in a single batch.

By most reports the difference is pretty minor. I can't think how the problem you describe is related to connecting / disconnecting the pulse generator. If you've had your fuel injector wiring off lately, you may want to check and make sure that all the wiring clips are firmly connected to the top of the injectors. I've seen problems (MARTIN!!) with loosely connected injector wiring causing intermittent firing.

Jeff

[genphreak]

The pulse generator triggers the batch fire sequence for the fuel injectors.

The Motronic 1.3 on the BMW is setup to fire the injectors in two timed batches of three each. This is to more closely align the injector pulses with the valve track. The pulse generator is the trigger for timing the sequence.

If the pulse generator is disconnected the injectors fire in a single batch.

By most reports the difference is pretty minor. I can't think how the problem you describe is related to connecting / disconnecting the pulse generator. If you've had your fuel injector wiring off lately, you may want to check and make sure that all the wiring clips are firmly connected to the top of the injectors. I've seen problems (MARTIN!!) with loosely connected injector wiring causing intermittent firing. Jeff

Thanks for the light on that Jeff. I was hoping it made little difference, perhaps it is an emissions control feature. However it definately does what i said. And they have them on M20s too...

I just put the millerperformance maf kit on a few weeks back, so it might have been learning around that prior. This one has me well stumped. I'll keep troubleshooting... and report back, thanks again.

[Jeff N.]

The E30 or the E34?

Like to chat with you a bit about the Miller MAF. I'm running the PRO-M racing MAF (the one Bruno was briefly marketing, PRO-M is now defunct) and we might benefit by comparing notes. A MAF conversion could create some of the issues you describe.

I've run my car (pre-maf conversion) with the the pulse generator connected and disconnected and it had basically zero effect on how the car ran. Not discounting your experience as I can only relate what I've personally seen\

Couple quick questions on the Miller MAF; curious about them as they are not too far away from where I live (couple hour drive):

- does it have any mixture or voltage adjustments?
- does it have an air temp sensor?
- have you noticed any changes in the cold run of the car or when the air temp dramatically changes (such as a cold winter day to hot summer day)
- what chip are you running?
- what's been your general impression on the MAF and power? Any before and after figures (I don't have any for mine)

Cheers!

Jeff

[genphreak]

The E30 or the E34?

Like to chat with you a bit about the Miller MAF. I'm running the PRO-M racing MAF (the one Bruno was briefly marketing, PRO-M is now defunct) and we might benefit by comparing notes. A MAF conversion could create some of the issues you describe.

I've run my car (pre-maf conversion) with the the pulse generator connected and disconnected and it had basically zero effect on how the car ran. Not discounting your experience as I can only relate what I've personally seen\

Couple quick questions on the Miller MAF; curious about them as they are not too far away from where I live (couple hour drive):

- does it have any mixture or voltage adjustments?
- does it have an air temp sensor?
- have you noticed any changes in the cold run of the car or when the air temp dramatically changes (such as a cold winter day to hot summer day)
- what chip are you running?
- what's been your general impression on the MAF and power? Any before and after figures (I don't have any for mine)

Cheers! Jeff

Today I left the car outside after getting to my destination with the PG disonnected. After a few hours shut down I came back to drive a good 30km again, but this time before starting plugged in the PG wire. All was good, in fact I have to say it felt better but one really has to be careful saying that. I did not reset the ECU just connected the PG and drove.

All good, but I am really wondering why it behaved like it did mid-trip this morning when I happened to notice it disconnected on a quick check.

Re the Miller MAF, there is a temp sensor just beside the hot wire. It is housed inside a gorgeously machined billet aluminium body. And of course they give you their own chip so the ECU has been modified..

Differences with hot and cold days? In Sydney it is a min of 10 degres and 34 degrees in the summer. so it s hardly a testing parad

In terms of running, it feels great. I have to say as much as the EAT chip makes these cars sing, the MAF went a step further but it removed the flat spot- and the low power she had when driving on and off idle- which of course was probably my AFM. But power feels up thorught the range. Now if I put my foot down it really flies.