Weber 750 & Megasquirt ECU

[Canadian Rhino]

Originally Posted by WHY

Well to say it has been an education, would be a major understatement. But learning how to wire the Microsquirt to the Weber has be quite a learning curve, especially when you start out not knowing $h-t from apple butter about computer logic and how some sensors work. A short "in the nutshell version" would be to say that what you have is "Weber specific wiring" and "Microsquirt generic wiring" and what you want is "WEBER-SQUIRT" wiring.

After many e-mails to Matt at DIY-autotune and many phone calls to Randy at Weber-Power out in Washington, it looks like I finally have the "WEBER-SQUIRT" wiring. Thank goodnes for the delay on my gearbox housing adapter or I would have been fighting a major headache in getting things to run due to confusion in how to wire things up.

It's one of those things that when you look back you can say, well that wasn't so hard, but until you get to that point it's a real puzzle. Everything is really pretty straight foward until you get to the "timing". There are 2 sensor inputs to the timing program in the Microsquirt, one for the crankshaft and one for the cam shaft. The crankshaft uses a "missing tooth" gear for timing and the cam uses a couple of lobes for "phase' sensing".

I have explained the "little gremlin" between the Weber crankshaft sensor and the Microsquirt wiring input in the previous post, so I wont go into that again. However there is some very confusing info on the cam sensor wiring. As I stated there are 2 timing inputs, crankshaft and camshaft, in the info and pictures in the Microsquirt literature and instructions it shows that "input # 1 (the crankshaft) you have 2 options,--- 1, you can use a hall effect set up or 2, you can use a VR set up. Well the Weber uses a VR on the crankshaft so naturally you chose the VR set up for "input # 1. Now the cam set up is "input # 2, and it has only one choice and that is a hall effect sensor and again Weber uses a Hall effet sensor on it's cam, so "no problem" right ????----- WRONG !!! Here is the second "little gremlin",-------ESPECIALLY FOR ME !!!!! until I got a little education on sensors. In the picture of the timing options in the Microsquirt instruction, they show the Hall effect sensor option in the crankshaft input as having only 2 wires and the Hall effect sensor in the camshaft sensor as having only 2 wires. WELL-------Hall effect sensors use ---3---- wires, a signal wire, a ground wire and a voltage supply wire, and the wiring harness only has --- 1--- wire for the cam sensor, and that is the signal wire. After close review and much head scratching I see where the cam sensor is using the same ground wire as the crankshaft (the shield on the coax wire), this is rather difficult to connect to since the only way to do this is to make a small pigtail on the shield braid and try to solder a wire to it without melting the center insulation and shorting the cable, then run this new wire all the way thru the harness to the cam sensor. Ok that's 2 wires, but what about the third wire (now it gets crazy) I am told that the sensor will use either 12 volts or regulated 5 volt logic supply voltage (apparently 5 volts is some kind of design standard for logic use), more phone calls to Randy , the answer, is yes Weber uses 5 volts on the Hall effect, so all I have to do is pick up the regulated 5 volts from the Microsquirt that is used on the TPS and the MAP sensors and --GREAT PROBLEM SOLVED !!------WRONG !!!! At this point in time we now have to go back to "Genisis chapter one verse one". "In the beginning" Microsquirt designed this unit to be as small as possible and aimed it at the "motorcycle,jetski. ATV, snowmobile market. It just became so popular that it is used in the Hot Rod world more than anywhere else. To make this unit as small as possible Microsquirt took out everything that made heat and drew a lot of current (mainly controllers for ignition and injectors) that would be needed for engines with large numbers of cylinders and would put them in other modules, but for 2 cylinder set ups you would not need anything other than what was inside the Microsquirt module, this included the 5 volt regulator for the logic and sensor input power, to remain in the Microsquirt module. here is where the rub comes in. The 5 volt regulator has a capacity of about 200 ma. (so I'm told) but to keep things SMALL it only has a printed circut heat sink that is designed for about "20 MA." (the TPS and the MAP using less than 20 ma.) ----add the Cam sensor and you are pushing the heatsink capacity of the 5 volt regulator ------!@##$%%^^^&&*.

So-----now what,---well more phone calls to Randy and I find out that the cam sensors was originally used on 12 volts ---- -----It seems that when the cam sensor was used on 12 volts a problem would show up sometimes with the sensor getting burned out, why----- well the ignition coils are originally auto industry coils (as are all of the sensors) and the cam sensor is from the auto industry as well. The valve covers on most of the auto engines are aluminum and provide EMP/RFI shielding for the sensors and help ground the ignition coils, the valve cover on the Weber is plastic. With the cam sensor/wiring being on 12 volts it was more sensitive and therefore subject to EMP from the unshielded ignition coils. So Weber went to the 5 volt source and installed grounding straps on the coils down to the aluminum head, no more problems.

Ok, now fast foward back to where we were. Microsquirt elaborates to some extent about being cautious about keeping sensor input wiring seperate from high current wiring and talks some about EMP/RFI problems screwing up timing signal inputs. So at the very begining I chose to shield all of the ignition wiring from near the main module plug (as close as I could get to the large heat shrink band) all the way to with in about 1 inch of the coil and the same for the injector wiring. So I now have added braid shield from about 1 inch from the cam sensor (cannot shield the cam sensor itself) back to near the fuseblock to get away from EMP/EFI and all of this shielding has a mechanical connection to a ground wire that goes to engine/chassis ground .

On a positive note, a e-mail to Matt at DIYautotune confirms that they now use the "special SENSOR GROUND" for the cam sensor instead of the VR ground, which makes the ground for the cam sensor very easy.

Am waiting for one connector to finish the last harness and will be able to post a picture of the harness, looks rather simple and small compared to the other harnesses. This harness is for a NA engine, but the wiring for the turbo charge system is "cut short" and hidden in the Loom, (involves about 3 more connectors) Still must wait on the gearbox adapter before I can test run the engine.

Tony

Oh my god Tony I tried to read that 6 times
You have to learn to hit the enter button now and then.
When trying to read it from left to right you lose track of the next sentence start point when you go back to the left!
Anyway all sheild cables are always grounded on one end only.
Crank sensor is for timing only.
Cam sensor does not sense cam rotation but senses a rocker following the cam and its only fuction is to tell the ecu which cylinder to fire next.
If the cam sensor fails you have a 50-50 chance of starting the engine.
It just makes sure you start first time every time.
You could unplug it and still have the engine run.
Just wont start every time.
But when it does start it wont quit!
Clear as mud?

[WHY]

Hi Phil

I guess I type like I think hope I don't talk the same way

yup, learned about the grounding at one end some time back, interesting to know about how the cam sensor works though.

Tony

[Trackwelder]

So I am guessing that the ignition isn't a wasted spark system like on a harley where both cylinders are fired at the same time, is there a reason that that wouldn't work so you could use each sensor to power a different ignition system?

[All_In]

Hi Buddy
This thread is so enlightening!!!
Thanks for sharing!

Mark has left us for the grand adventure however he is still helping us with this thread!!!
Way to go Mark, not many of us humans have been able to do that?

[JEFF TIPTON]

Both the Megasquirt and Microsquirt can be configured to fire wasted spark or sequential in the case of the Weber.

[WHY]

HI John

Your so right about Mark, even though he has left for the big adventure, I will still be using his post on the "start up " readings when I get to the initial engine run. Information is "timeless"

Tony

[Canadian Rhino]

Originally Posted by Trackwelder

So I am guessing that the ignition isn't a wasted spark system like on a harley where both cylinders are fired at the same time, is there a reason that that wouldn't work so you could use each sensor to power a different ignition system?

The cam sensor is not precise enough to use as a timing device.
It just tells the ecu which cylinder is going to fire next long before the firing event takes place.
Also all shielded sensors are always grounded at the reciever end not the sensor end.
Guess I should have said that earlier sorry

[WHY]

Ok----CALLING ALL EXPERTS OR OTHERWISE !!

Have been looking all over for electrical specs on the cam sensor used on the Weber MPE-750, it is Bosch part number 0 232 103 033. I have only found this sensor to be used on one other vehicle, the Nissan Micra around year 2000. When I look up the Nissan Micra I also find a second number of 0 232 103 054. But am un able to find any electrical specs on either of these sensors

When Weber tried to use this 033 sensor briefly on 12 volts it would sometimes burn out from EMP from the ignition coil so they went to 5 volts and added a grounding strap to the ignition coil (may have helped, and maybe not) but no futher problems.

Now the Microsquirt has 5 volts regulated available for its MAP and TPS but the regulator for the 5 volts has a VERY SMALL heat sink in the ECU and Microsquirt feels that adding the cam sensor to the 5 volt source would make the heat sink marginal.

SOOooooooo my alternative is to find a 12 volt (or higher) sensor that will cross refference to the 033 unit (same physical dimensions) or I can make a outboard 5 volt regulator which is a little more work, I would just prefer to change the sensor to a 12 volt version.

Anyone out there around the world that can come up with any of these specs or a cross refference exchange sensor that will be a direct change out ????????

Tony

(hey Phil, notice I used the "enter" button )

[Canadian Rhino]

Originally Posted by WHY

Ok----CALLING ALL EXPERTS OR OTHERWISE !!

Have been looking all over for electrical specs on the cam sensor used on the Weber MPE-750, it is Bosch part number 0 232 103 033. I have only found this sensor to be used on one other vehicle, the Nissan Micra around year 2000. When I look up the Nissan Micra I also find a second number of 0 232 103 054. But am un able to find any electrical specs on either of these sensors

When Weber tried to use this 033 sensor briefly on 12 volts it would sometimes burn out from EMP from the ignition coil so they went to 5 volts and added a grounding strap to the ignition coil (may have helped, and maybe not) but no futher problems.

Now the Microsquirt has 5 volts regulated available for its MAP and TPS but the regulator for the 5 volts has a VERY SMALL heat sink in the ECU and Microsquirt feels that adding the cam sensor to the 5 volt source would make the heat sink marginal.
SOOooooooo my alternative is to find a 12 volt (or higher) sensor that will cross refference to the 033 unit (same physical dimensions) or I can make a outboard 5 volt regulator which is a little more work, I would just prefer to change the sensor to a 12 volt version.

Anyone out there around the world that can come up with any of these specs or a cross refference exchange sensor that will be a direct change out ????????

Tony

(hey Phil, notice I used the "enter" button )

Sorry but I have to call BS on that one!
The cam ensor is just a hall effect transistor which is a fancy name for a magnetic switch.
It does not sense the cam as suggested but only senses a valve rocker.
In other words if it senses valve on # 2 open fire coil #1
Switches do not consume power they control things.
In this case the hall sensor is just sending a 5 volt square wave SIGNAL to the ecu.
Thank you for leaning the return button trick!
It took me 2 days before I could cut firewood straight!

[WHY]

Well----------- after trying to get info on the cam sensor # 0 232 103 033, from Bosch supply sources and even trying to get spec info from Bosch USA and not being successful from either source, I have searched xteen thousand different sensor and believe I have found a 12 to 24 volt direct exchange, even the connector is the same.

It is a # 0 232 103 022 used in the Porsche 911 and Cayenne from about 1997 up to 2006. Have not tried it yet, just ordered one brand new off e-bay for about $136.

If this work out it will make the Microsquirt a breeze on the Weber.

Tony

[WHY]

Here are the pictures of the Weber/Microsquirt harness for the NA engine, a turbo would have 2 more conncetors (I think). The harness weighs 2 lbs, the large connector on the left goes to the ECU, the small pigtail pointing upward is the computer data connector. The 2 red wires on the left are 12 volt from battery contactor and 12 volt from ignition switch. The 2 wires below the ECU connector are the boot loader wire and the tach wire. The larger coiled wire coming down from the fuse block is the fuel pump 12 volt feed. The top small harness is for the TPS sensor and the one below it with the coiled pink wire extending from behind the connector is for the crank sensor, the pink wire is for the O-2 sensor. The larger cable curling down and to the left is for the cam sensor and the shorter one spliting off is for the Map/IAT. The little short one between the two is for the coolant temp sensor. The 2 on the far right are the ignition coil connectors and the 2 just left of them are the injector sensors. Would make one small change on the next one, would combine the Ignition and injectors into the same housing. SORRY PHIL, I DID IT AGAIN ON THE ENTER KEY

The picture on the right is of the 2 cam sensors that I have been looking for so hard. The sensor on the left is the original Weber sensor Bosch # 0 232 103 033 and the one on the right is the one from the Porsche Boxster/Cayenne 1997--2006 Bosch # 0 232 103 022. It is has a higher working voltage that the 033. It is rated at 12 to 24 volts, The original is rated 5 to 15 volts (so I'm told). I will be using the Porsche sensor. It is a direct exchange ----"IF" you are using a Bosch connector without the "outside" housing (they just snap over the connector and can be removed easily) It you are using a Delphi connector, the outside housing is molded onto the connector and while it will fit the 033 sensor with no trouble, if you use the Porsche sensor you must cut a recess in the lower part of the outside housing to clear the Porsche senor, no problem.

SOooooooo now I am waiting on the adapter housing for the re-drive to put everything together and fire it up--- well I guess I could start on the exhaust system ??

Tony

[All_In]

Wow Buddy you are going to fire her up!!!

I cannot wait!!!!!!!!!!!!!!!!!!!!!!!!!!!

[WHY]

I wonder if "2 weeks" is "twilight zone" time ????

Tony

[All_In]

Originally Posted by WHY

I wonder if "2 weeks" is "twilight zone" time ????

Tony

Hi Buddy!!!

Dang not Stan's 2 weeks!!!

[WHY]

Out of curiosity, would like to know what kind of ratio the interest is between the normally aspirated (NA) and the turbo, or how many would be interested in the NA and how many would be interested only in the Turbo.

The NA is around 72 to 75 hp and the standard turbo is arount 120 hp (I think). The turbo installation will be somewhat more involved I am quite sure.

Tony