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[lozzzzzz]

Thanks F1 9LFG, I'll keep posting whenever there is progress

The spike is just reaching 0.3V, but when connected to a multimeter to give ac voltage, it reads 0.9V rms, not sure which to believe really. 

[Marks DTM Calib]

The variation in amplitude is a bit of a concern (e.g., as if a sinusoid is superimposed on it!).

As a pointer, Vx used the DIS pack mount as the main graound point where three wires connected in order to produce a good un-disturbed ground for all the sensors, actuators and the ECU.


As for the mutimeter reading, is it a good true RMS meter. If not then its a false value as it would be assuming a sinusoid (which its not) 

[lozzzzzz]

Mark, I was worried about the Overlayed Sin way too, but David at Canems didn't seem to think that was a problem, probably just hte variation in engine speed at cranking due to compressions (there are 3 every rev). 

A little Update,

I've since tried it with the ECU connected, and its very much the same.  I've measured the eccentricity of the trigger wheel too, and its less than 0.2mm out with a gap of about 1.5mm (not the 3mm I'd previously thought. 

David at Canems kindly put another ECU together for me with "reduced sensitivty" I'm afraid the ECU bit is a little beyond me, but it should be more tolerant of a weak signal. 

Got that through in the post the other day and tried it, Exactly the same thing happened

So I tried the loom they send through too, its just got the power wires and the CPS signal wires and thats its!  Its completely free of anything on the car, and anything I've made, I even connected it to a different battery to the one that was cranking the negine, it still showed the problem!  This is now far beyond my understanding, I'm hoping hte ECU fairy will fix it one night while I'm sleeping. 

I'm waiting to hear back from David at Canems again now, I can see my only two options being, get a different ECU (different make) or fit another trigger wheel on the engines front pulley. 

More to come

[Kevin Wood]

The ECU will be looking for the zero crossing points of the signal so, as long as the amplitude is high enough to overcome the hysteresis of the detector circuit in the ECU, it should be irrelevant.

Might be worth asking the ECU manufacturer what it is, because the only thing I can imagine might be wrong with that signal is that the amplitude is too low or the version the ECU is seeing is noisy.

[lozzzzzz]

I see what you're saying, I've emailed all the info, with lots of photo's and CRO traces to the ECU manufacturer, I'm a little out of my depth when it comes to understanding signals and programing. 

I'll post up the ECU manufacturers reply soon. 

[lozzzzzz]

OOO I never posted the reply, Canems, have suggested that the next port of call be to put a trigger wheel at the front of the engine

I just want it working so here goes. 




I've found a little time to mess about in the garage.  I've mostly been cleaning up everyone elses s***, but its all sparkly now:



So I've started looking into the next idea to fix the engine running problem.  I'm going to machine up the engine pulley to become the new trigger wheel and mount  the sensor up front.  Here are a few photos of the front end and pulley. 






I really really really really can't wait to have this part of the project behind me, and get back on with finishing the car. 

Next port of call for today is to find a new inverted to get the lathe running again. 

More to come. 

[Andy B]

.....
I've found a little time to mess about in the garage.  .....

.....

Where's the green with envy smiley when you need one? 
I NEED a garage like that ......... with a lathe in the corner! 

[tidla]

the scope patterns dont look right.

http://www.picoauto.com/waveforms/Sensors/Crankshaft

make sure the scope earth is connected to the body close to the source and not on the battery.

[lozzzzzz]

Tidla,

I'm really sorry I hadn't spotted your reply, I'll have a good look through that article when I've got more time. 




I've ordered the recommended crank sensor for a machined front pulley , the 3rd one now!

Anyway when I had dropped the CRO off with my friend, we had time for this fun beforeI returned.......






So a few months back I went to see my good buddy pete, (we were at uni together) now most people would be happy to laze about and catch up but not pete, first thing saturday morning we were off to the scrappy to get the bits to make a jet engine. 

We got did it, we made a jet engine in well under 48 hours and fired it up that weekend, its was a lot of fun.  Pete did the research before I got there, he did lots of cutting and lateral thinking around problems, and sourcing the parts, I did the calculations for the flame tube and the welding. 

When I turned up this time, he and another friend have mounted the jet in a BBQ!!!!

What an Amxing BBQ, we fired it up for the first time in its new home, and it cooked a sausage in no time!



Here's the bit me and pete made:


This is how to start it with the leave blower:


And antoehr vid of it running:


Cool or what (well maybe pointless)

[Vamps]

.....
I've found a little time to mess about in the garage.  .....

.....

Where's the green with envy smiley when you need one? 
I NEED a garage like that ......... with a lathe in the corner! 

I was having similar thoughts Andy, even more room to fill with junk.......

[albitz]

Jet engine in bbq - no idea why,but its brilliant.

[Andy B]

... even more room to fill with junk.......

That's always the flip side ....... 

[Vamps]

... even more room to fill with junk.......

That's always the flip side ....... 

My garage is an embarrassment, full of so much junk, tools and things that will come in handy one day......
It leaks live a sieve at the moment so needs a new roof, that should encourage a good old sort out.....

[lozzzzzz]

Thanks folks, the BBQ is kind of nuts!  Me and pete wanted the engineering challenge of making a jet really, then his mate did all the amazing craftmanship on the actual BBQ. 

He's really into making very randon things, he holds the guiness world record for the fastest mobility scooter, and the worlds longest motorcycle, he held the record for the largest bonfire too but that was beaten 6 months later.  There are some interesting vids of his on youtube under Collin Furze.  He's hoping to get the BBQ in a national paper of some sort or a lads mag.  All this nonsense has got him contracts with tv companies making randon things for shows. 

I'm very lucky yo have a garage like this (this might be part of the reason I'm still sponging off my parents ).

I've had a glance at the sensor trace articles, and I think mine looks ok, its very similar to this one:

http://www.picoauto.com/waveforms/Sensors/Crankshaft/wave101.html

Except I had the CRO set up to squash the wave up a lot more so that one crank rotation fitted on the screen.  But the "lumps" are there on mine and the website (the variations in the speed due to compressions), and the spike (due to the gap), and each tooth, although mine are a lot closer as the CRO was set up differently (the timebase). 

I'm more than happy to be corrected, but I think its ok??

[Kevin Wood]

I've had a glance at the sensor trace articles, and I think mine looks ok, its very similar to this one:

http://www.picoauto.com/waveforms/Sensors/Crankshaft/wave101.html

Except I had the CRO set up to squash the wave up a lot more so that one crank rotation fitted on the screen.  But the "lumps" are there on mine and the website (the variations in the speed due to compressions), and the spike (due to the gap), and each tooth, although mine are a lot closer as the CRO was set up differently (the timebase). 

I'm more than happy to be corrected, but I think its ok??

All your traces have looked fine to me. You can see that when the amplitude drops so does the frequency. It's just the engine passing each compression stroke as you say. I really can't understand why your ECU isn't happy with it.