318i M40 turbo 190bhp@8psi *Breaking*

[ShakeyC]

After fitting the new plugs my whole map went lean, does this mean i'm burning more fuel and the engine is running better or does it mean that all the fuel isn't being burnt so easily and more fuel is needed and some is being unburnt?

I'm going to try to get it running wasted spark later, will I be able to open up the plug gaps? If so by how much?

With increased heat and pressure inside you need more voltage for the spark to jump the gap in those conditions, also with colder plugs the tip of them do not protude into the combustion chamber as far either for same reason. Combined together i think you gone bit over kill suggest first regap the plugs back to standard and see what happens. (It should make it bit richer again)

If it went lean (I don't know any figures your comparing it too) it means you have more air than fuel. If dangerously lean it will detonate under load so not good, ideally aim for 14.7 AFR to start off with, beware around peak torque as this is where changes to spark plugs become most evident!

[chu346]

If it went lean (I don't know any figures your comparing it too) it means you have more air than fuel. If dangerously lean it will detonate under load so not good, ideally aim for 14.7 AFR to start off with, beware around peak torque as this is where changes to spark plugs become most evident!

It went lean across the whole map. As soon as I started the car I noticed the idle afr was 16.5+, and when I reved it whilst stationary it was worse and cutting out. So I added 20% more fuel across the map and tuned it down from being rich to get back to my original afr's. Been out in it for a couple of hours tonight tuning fuel, spark and the boost map, and all is well

Didn't get round to adding wasted spark, I'll leave that for the weekend. Whilst I'm doing that I'll return the plug gaps back to standard.

[chu346]

how much for the manifold?

You want the one I've got on at the minute?

If so you'll have to wait till mid july when I build another for my new turbo. My new turbo doesn't have a built in wastegate and I can't seem to find a decent way of adding an external one to this manifold so a redesign is needed.

Would you be interested in the manifold, turbo and the downpipe too? I would like to sell it as a whole, as it would be a nice bolt on package considering the downpipe bolts on to the back box.

[ShakeyC]

You will find you may have to undo some of that 20% increase in fuel across the map to get it back to nearer how it should be when you put the plug gaps back to normal.

[chu346]

I understand that, but I don't understand why I've had to increase it in the first place?

[cypriot_boy_2k7]

chu u have pm

[chu346]

Replied, sorry for the delay!

[RowdyBurns]

If it went lean (I don't know any figures your comparing it too) it means you have more air than fuel. If dangerously lean it will detonate under load so not good, ideally aim for 14.7 AFR to start off with, beware around peak torque as this is where changes to spark plugs become most evident!

Don't listen to this man. He has obviousy never mapped a forced induction, if infact, any car.

Running as lean as he has suggested under load is a huge mistake!

[ShakeyC]

If it went lean (I don't know any figures your comparing it too) it means you have more air than fuel. If dangerously lean it will detonate under load so not good, ideally aim for 14.7 AFR to start off with, beware around peak torque as this is where changes to spark plugs become most evident!

Don't listen to this man. He has obviousy never mapped a forced induction, if infact, any car.

Running as lean as he has suggested under load is a huge mistake!

edit sorry i should have worded that post better, start off with 14.7:1 without load at idle, i didnt mean under load at peak torque to start at 14.7:1 AFR as it comes across as, sorry

[RowdyBurns]

You should be very careful how you word your advice and be 100% confident from experience. You could have cost him his engine.

[ShakeyC]

It reads fine to me but as you pointed out i re-read it again and again i can see where mis-understanding has arisen from on my part for not writing it better and clearer as i usually do.

[e30_Turbo]

@Doug.

ShakeyC is in the know my friend, he's just worded it wrong. I'm sure he could be a useful asset to any zoner and has been many times. Maybe he'll enlighten us to his credentials, not that I need to see them, Ant speaks highly off him and that's enough for me.

What you been upto anyway? Did Martin finish his turbo 1000cc bike?

[RowdyBurns]

Thats built and long gone.

I've been flat out recently. Some of the fabricated bits i do for cossie engines have really taken off and i'm struggling just to keep up.

Keep thinking i might see you at one of bbbs barbeques but you never turn up. Is the E30 on the road still?

[ShakeyC]

Im genuinely very sorry for any mis-understanding, a very rare lapse on my part that i admit and clarify openly. Thank you for pointing it to me RowdyBurns

[e30_Turbo]

I haven't made it due to being friday nights and family commitments, I still pop over when I can but just not enough really, my cars still on the road but my turbo engine is now in the garage while I build another manifold and rebuild the bottom end to a resonable spec, unless I get tempted to go for a M52 which is something I'll decide on depending on the amount of work my engine needs. Nothing broke, melted or busted, just had enough of det in the wrong places and showing signs something wasn't right. Time to find out without needing to have it all back together for work on monday morning.

If you're in fxto one night call me, I should have it in bits by the weekend.

[RowdyBurns]

If you need a hand with any ally/stainless fab work give me a shout.

[e30_Turbo]

Now you say that, I have some 3 inch ali tube and some 2 inch, just looking for someone to help me tig it after I finish getting the parts cut and flared, just missing some sheet to fill in the gaps. Are you working at the same unit during the day? I'm usually going that way once a week.

[RowdyBurns]

Only over there saturdays and some evenings. Give me a shout when you need it doing and i'll make sure i'm there.

Can weld that up for you no probs. Will cost you a bacon and egg roll from the local burger van though!

[e30_Turbo]

ok, deal

I'll call you soon

[chu346]

Finally got round to fitting wastedspark today but i'm getting rpm spikes. I'm using a vauxhall redtop coil pack. You can see on the datalog that it jumps upto10660rpms



Any idea on what the problem could be?

[Ant]

MLV uses the cranks sensor signal for its RPM display same as MS so any spiking in that signal can only be related to a bad earth in there somewhere or the shielding on the sensor is duff??

where did you place the coil ?
did you use the vaux plug( 4 pin) and have you retained the small cap for noise suppression??
are you using the OEM leads ??
where is the return ground from the twinned coil igniters terminating ?

I see the issue relates to the TPS load more than anything else, so again, check ALL the grounds for security and spurious high resistance values.

12 psi, nice ! spikes to 12 and drops to sustained 10 or so it seems.

Have you revised the settings for dwell too BTW ? crank @5, running approx 2.2 min discharge around 0.2m/s

[Gunni]

The CLT signal can be seen to show some noise.
So there has to be something going on ground wise.

[chu346]

MLV uses the cranks sensor signal for its RPM display same as MS so any spiking in that signal can only be related to a bad earth in there somewhere or the shielding on the sensor is duff??I've had no problems before I fitted this, this afternoon.

where did you place the coil ?on the corner of the battery tray

did you use the vaux plug( 4 pin) and have you retained the small cap for noise suppression??I used a 3 pin plug that came with the coil pack. The coil pack is from an early calibra. What small cap?

are you using the OEM leads ??I'm using the M40 leads because there is a wire on lead 4 that goes under the intake manifold.

where is the return ground from the twinned coil igniters terminating ?I don't think it has a ground?

I see the issue relates to the TPS load more than anything else, so again, check ALL the grounds for security and spurious high resistance values.
It does it abit at low loads too.

12 psi, nice ! spikes to 12 and drops to sustained 10 or so it seems.

Have you revised the settings for dwell too BTW ? crank @5, running approx 2.2 min discharge around 0.2m/sNope current settings are cranking 3.5, running 3.0min discharge 0.1, I'll change them in the morning.

The CLT signal can be seen to show some noise.
So there has to be something going on ground wise.I've built my MS into the motronic case, so all the MS wires ground to the case and then through the motronic connector. Should I run another earth?

[UweM3]

awesome work dude! One day I might go to the dark side and use one of those fans as well. Just too tempting.

[Gunni]

Chu can you get some picks of the coil pack?
and any wiring modification you´ve made.

[GeoffBob]

Chu, here's my few pennies worth:

Your ECU "interprets" your engines RPM by counting the number of pulses from your crank sensor over a given period of time. If the signal from the crank or flywheel pickup is on the smallish side, or corrupted with electrical noise, the comparator at the input to the ECU will sometimes see the signal from the pickup as a multiple pulse, causing its interpretation of your RPM to jump spuriously high. In other words, it starts counting multiple pulses where there is only actually one pulse.

The easiest way to diagnose this problem is to connect an oscilloscope to the wires from the crank sensor where they connect to the ECU box and look at the actual signal from the sensor (BTW, that's not what you see in your screen-shot above and this cannot be shown via the software). Without an oscilloscope (and I understand not everyone has one) it becomes a process of trial and error to rectify.

Probably the best tip I can offer you, however, is to make sure your crank sensor has its own ground (zero volt) return line to the ECU via its own wire that runs closely (preferably twisted together) with the crank sensors signal wire. Do not, and I mean do not, ground it to your engine as this will cause it to pick up electrical noise (due to the return currents flowing in the block from the spark plugs). For that matter, none of your sensors (temp, MAP, knock etc) should be grounded through the block and must have their own ground return line to the ECU.

Also, make sure your engine has its own broad/fat earth strap back to the battery negative pole (chassis) to take care of its own earthing requirements.

One final point, the proximity of the nose of the sensor to the toothed surface over which it generates its signal is important. Too close and you can generate a signal that saturates the input stage of the ECU at high RPM, and too far and the signal is too small to be detected properly.

I hope this helps. It'll probably turn out to be something altogether different, but I thought I'd try for what it's worth.

[Gunni]

The thing is that he was using this without any problems at all before he installed the wasted spark.
All stock BMW sensoring and installation.


Coils don´t need their own grounding unless they have built in Amps/igniters.
There has to be a noise related to the new current path of the high voltage in the leads that is corrubting the crank signal. I.e they are running to close to eachother perhaps.

The pulse inducter on the ht leads does not need to be hooked up as megasquirt has no use for it.
That may be giving out noise as it´s possibly not grounded near the ecu but left hanging. That wire runs along the crank signal, although shielded , but when the shield is not grounded it´s not effective. I usually cut them right off the HT leads.

That´s why we need to know exactly what Chu has done so to isolate the potential problem.

Everything Geoff said about crank signals is true. And especially critical in a new custom crank trigger setup.

[GeoffBob]

There has to be a noise related to the new current path of the high voltage in the leads that is corrubting the crank signal. I.e they are running to close to eachother perhaps.

Or the fact that the wasted spark ignition fires each plug twice as often as a normal ignition (before every TDC as opposed to before every alternate TDC), and thus generates twice as much electrical noise as before, tipping an already sensitive sensor (with possibly faulty shielding and/or faulty grounding) occasionally over the edge?

FYI, I'm not disagreeing with you Gunni, just making another suggestion.

[Ant]

I mentioned the ignitors as they are internal to the ECU not the coil and MUST have a separate Ground lead not through the ECU connector or PCB.

Given it was "perfect" on the stock single coil, perhaps there is a hairline crack in the coilpack and it's making a HT ground to the car shell @ the fixings ?, had it happen to me on an M20B25 before.

would give all the symptoms Matt(Chu) has listed IMHO.

New pack or good used ??

Agreed the inductive sensor is not required and I'm with Gunni, if in doubt cut it out !

Perhaps go back to the dizzy and re log , see if all is good ????????????

[chu346]

The coil pack was donated by a friend, it worked ok in his car. But I'm not ruling it out.

I've tried:
Changing the leads, I'm using the ones that came with the coil pack
New earth for the battery
Added a new earth to the ecu case (8awg)

Ant by ignitors do you mean the bip373's? I have one in the standard place and another wired seperately, could this be the problem then? Will I loose my tach if I move the original one?

[e30_Turbo]

Second hand coil packs are a false saving, wasted 30 on one before getting a real one from a vauxhall spares place in essex, 6 pot ones are around 75ish.

Mine has given me a whole array of issues, from failing HT leads to internal cracking and don't get me started on the earthing side of things, hate the plug to the coil pack also, long story.

Earth it all to one point on the block, that's what Phil Ringwood told me, that's what I've done, no issues for a while.

It's worth the aggro, unless COP is possible, that's a much tidier solution IMO.

[Ant]

@ Matt.

ditch the on board one ( remove the jumper and leave in situ for ease )

fit 2 on the lid of the ECU as directed, VBz's need to be heat sinked, BIP373 or similar need insulating dude.

run the ignitor grounds back to the chassis earth directly, should rule out any signal noise then, the OE MS one is very noisy @ the DB37 if you scope it, hence why most MS builds are now using an additional connector for the "extra" goodies

re the PnP MS, provided all the OEM grounds are in place as per pinout, and they all terminate (eventually) to the factory earth point that should not be the cause, I'd assumed this was carried over from the existing with dizzy setup yup ?

It WILL be a simple fix, always is

[chu346]

Well,

I used the one on the board. Took the pins out the board then wired it like you said, but no joy. So I'm back on the standard coil now.

What coil packs are usually used on 4pots with megasquirt?

Also I'm going to make a big brake kit and would like to know what metal should be used to space the caliper? Is stainless steel good for the job?

[cougar]

fowler

i like the wait saving water bottle conversion

[Gunni]

Well,

I used the one on the board. Took the pins out the board then wired it like you said, but no joy. So I'm back on the standard coil now.

What coil packs are usually used on 4pots with megasquirt?

Also I'm going to make a big brake kit and would like to know what metal should be used to space the caliper? Is stainless steel good for the job?

Get this for 6cyls

http://cgi.ebay.co.uk/Vauxhall-VECTRA-O ... 1|294%3A50

And this for 4cyls
http://cgi.ebay.co.uk/Vauxhall-ASTRA-OM ... 1|294%3A50