MS extra siamese sequential tune (msq) to start with
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Schrödinger's cat - so which one am I ???

http://www.jbperf.com/

Hi guys,
My knowledge of fuel injection en the peculiarities of the A-type engine around this subject is slowly building up.
The way I look at it now is that the sensible way to go is the dual pulse mode single pulse mode sounds to me as a critical thing to time.
I will start with trying to measuring inlet travel times by setting the pulse for cyl two early enough that nothing of it will go into cyl one. Than I will move the mid pulse of cyl one later until I see that cyl 2 starts running richer after that I will repeat this but than by moving the pulse of cyl one earlier until the same thing happens (cyl two running richer) My guess-temate is that mid pulse should be somewhere in the middle off those two numbers. Before I start this I will time my engine accurately by setting ignition advance to 0 and strobe it to exactly TDC.
I can not wait to get going with this but I first have to take my manifold of to weld in the second wb lambda. I will weld bungs to all three branches. This should all be ready next Saturday I will keep you all informed.
In My first job I was an electronic design engineer building single chip processor interfaces for laboratories so I will give it a try to read and understand the source code of Jean. In those days (around 1985 to 1990) we were using Intel processors like the 8048 and 8051 I wonder how much of that knowledge is still hidden somewhere in my fussy brain. (As it was quite a struggle already to get working again with my digital scope after so many years, so much buttons and no user manual I won’t expect it to be easy ).

Before I start welding the sensors on the manifold branches, does any of you know how critical the temp gets in the manifold in relation to the lamda probe? According to the doc it should not be mounted to close to the cyl head because of the heat but on an a-series you cant move it away very far Is this a real problem? should I make provisions for cooling? Longer bung or something else?

Regards Will

I used to measure EGTs on my NA trials.

I saw 700 Deg C on the outers and 800 Deg C on the inners.

If you are using an LCB, I would recommend fittings the sensors after the join in the legs from the outers and the inner sensor alongside.

I had no problems doing it that way, but I think the recommended maximum temperature is 500 Deg C.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

When I did my initial testing (normally aspiratated) I used an A-plus part cast, part tubular manifold and put the two on the tubular bits about 300-400mm from the head.

There is a photo somewhere on the forum, I'll try to find it.

Too hot is better than too cold for the location as you can add a heat sink, just a home made copper plate with fins under where it screws in if it really is too hot.

Schrödinger's cat - so which one am I ???

The second wb lambda is in place now. I removed the Edis system and built a cam trigger from an old electronic distributor so now I can run fully sequential.

I will try to put my thoughts in writing and will update this thread as I am working through the setup of the engine.

I have timed the cam sensor to give a falling edge exactly on TDC of cyl 2 this is 180 degrees before TDC of cyl 1 and about 90 degrees before the missing tooth on the crank. So the falling edge of the cam will be my reference for timing measurements.
1st Scoop picture:
Channel A is the 36-1 crank signal channel B is the cam signal

First checks:
Ignition cranking timing set to tdc, injection cranking timing set to 0 and timing trigger set to start of pulse, removed all plugs and fuel pump fuse.
First injection pulse starts exactly on TDC (cyl 2) and next pulse occurs 180degrees later which is TDC of cyl one.

2nd Scoop picture
Channel A is injector cyl 1/2 channel B is cam signal.

So far everything seems to be oke
Next test will be to shift the injection pulses to see how the timing works.

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That looks good.

I set my cam pulse (using rising edge as I use an opt-switch) about 75 degrees before the missing tooth. I was aiming for 50-60 degrees before the missing tooth but missed.... but your 90 degrees sounds just as good.

Mine.

Schrödinger's cat - so which one am I ???

This is a bit anal, setting the cam sensor timing.

I just fitted it and it ran. I twisled it to the left and it missed and then I twisled it to the right until it missed, then set it half way between and have since forgotten about it.

Let's not make it more compliccated that it is.

Yours......... Grumpy

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Schrödinger's cat - so which one am I ???

I have set the cam sensor accurately to a known point just to be able to use it as a reference signal while checking injection and ignition timing for this reason alone its not completely useless to set it accurately. I know the cam sensor timing is almost irrelevant as it only means that the next missing tooth will be cyl 1 on intake stroke.
Just did some more testing, had set first injection timing to -45 and second timing to +45.
Cam period while cranking was 383 msec (313 RPM) cyl 2 pulse moved to 23 msec before TDC cyl 1 pulse moved to 24 msec after tdc so that means, when I did the math right, that everything is working as it should be.
Next test will be firing up the engine and after warming up try to find the best value for req. fuel.
I will start with injection timing set to midpulse 45 degrees ATDC.

Will

The point is that the crank sensor does all the timing. The cam signal merely sets a flag in the code to make sure that the ECU knows that whether its on the induction stroke or the power stroke.

There is a wide window for the cam sensor timing in which it will work.

Aplogies for coming across negative, but we have a habit of making the EFi thing seem more complicated than it is.

You don't need a scope to set it up.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Schrödinger's cat - so which one am I ???

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Will,

As above ^^^

I too started with 45 ATDC (ie -45) because I hadn't appreciated the significance of transit time. Although it ran on all four the AFRs were well apart.

I found that 0/+45 or +45/+90 were much better (can't remember which was best out of those two but certainly BTDC figures).

Schrödinger's cat - so which one am I ???

Hi Paul, Rod.

The 0 .. 45 BTDC are these start of pulse or mid pulse timing?
Battery was flat after 15 min cranking and measuring so could not start it today.
Going to start the engine tomorrow and see what it does, I wil start with your timing and work from that.

Regards Will

P.s.
After looking at the VR plot you posted I understood why I had to set input capture to falling edge. Polarity of my VR sensor (ford type with two wires and no polarity indication) is reversed.

In my case, mid pulse although at idle it probably makes little difference as the pulse width is so small.

Beyond idle, Paul will have to advise as my testing is limited to idle (I had intended to get the car on the road this week, the only outstanding job is fuel pump but with sub-zero temperatures inside my garage and 4" of snow outside I haven't had the enthusiasm to lie on the floor and crawl underneath to do it...).

VR polarity is annoying, I have the full Ford Technical Information System on DVD so I was able to cross reference several wiring diagrams to work it out (the plug has a tiny "1" and "2" moulded into it and the numbers are noted on some of the wiring diagrams).

Schrödinger's cat - so which one am I ???

I always use mid-pulse.

If you use start or end, then any pulse width variations, such as a change of injector size, will mean starting a new timing map.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Hi,
Just started the engine it started very quickly but I am experiencing a sudden cut out of ignition above say 1200 rpm and due the big overlap of the cam (286) idle below 1000 rpm is at the very irregular. All tables are looking good.
I have to sort out the ignition problems first.
Regards Will

polarity still wrong on the sensor ,or air gap too big will?

Edited by robert on 23rd Dec, 2009.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

missing the suppresor from the +ve feed on your ignition coil?

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

Thanks for your reactions,
I had corrected the problem with the VR sensor polarity already and had the supressor capacitor also installed.
Ignition was not a problem when I was running the Edis system. But moving to sequential injection meant also that I had to remove this system however I still use the same ford coil pack.
At first glance it seems that there I have a problem with the cam sensor because this signal goes all over the place at higher RPM. I will check this out tomorrow.

Regards Will

Do you have a shielded wire for the cam sensor?

Jean

http://www.jbperf.com/

I don't think you mentioned earlier exactly what you used for your cam sensor apart from building it into a dizzy housing.... Depending on whether you used a Hall switch or an opto-switch, it may be that the value of the resistor you used inside the Megasquirt box is wrong so losing the cam signal once RPM rises.

Also, if you are using a Hall switch, the air gap may be wrong so losing the signal as RPM rises, the same as happens with the crank sensor if the gap is wrong.

The other problem I have seen very recently is a wrong value for C31 causing a loss of primary tach signal above 1400 RPM but you would have seen that if trying to raise the RPM on the JimStim as well.

EDIT - and also, are you showing a loss of synch in TunerStudio when it misfires ??? It may be that you need to adjust the VR pots in the Megasquirt to suit the actual VR sensor arrangement on the engine as opposed to any testing on the JimStim - I have two completely different settings for R56 between the JimStim and the engine.

Edited by Rod S on 23rd Dec, 2009.

Schrödinger's cat - so which one am I ???

I use an electronic ignition distributor from an MG Metro connected to the M-Squirt hall input circuit (with added pull up resistor of 470ohm). I bended three of the four rotating blades downward so they don’t pas they stationary blade anymore (snapping them off would have disturbed the balance I reckoned) and snapped off three off the stationary posts and connected the M-squirt to the terminal that normally fires the coil. I blocked the centrifugal and vacuum advance. The signals looks very clean at cranking and low RPM and then suddenly starts moving all over the place just before it completely stops, when RPM drops the signal comes back again very clean. Normally the four blades (one for each cyl) are operating in parallel seems to be some kind of hall sensor internally but than quite big. I thought snapping three blades off would not harm the signal strength to much but perhaps I was wrong about that. I will check this further this evening by operating the distributor on a mill and doing some bench testing. I added two pictures of the setup.
It first this seemed to be a very quick way of getting a cam signal as I had the distributor laying around.
Regards Will

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Removing (or bending down) three of the four blades is logical but without knowing why there are (or were !!!) four posts - I would have expected only one for a Hall switch - you may well be right about signal strength.

As you say, spinning it at different speeds off the engine and watching the output on your scope will soon tell you.

I have a spare one in the garage, I'll have a look inside today just out of curiosity.....

EDIT - one other thought Will, as the electronic dizzy has the amplifier unit on the side, ie, it is not just a Hall switch but a Hall switch with an amplifier to swich large currents through the standard coil, the 470 ohm resistor pull-up reistor may not be appropriate or an unsuitable value.

I suggest you wire one up (outside of the MS box) when doing your bench test to see if it is having an effect.

Edited by Rod S on 23rd Dec, 2009.

Schrödinger's cat - so which one am I ???