Webber 750 engine

PS:
The easy way would be to just hook the sensors up to my computer oscilloscope and read them while running. That would make it easy to setup the Microsquirt program too.

I could send it to you and walk you through recording the data to send back to me?
 
John

I think that once the smoke settles, there will be basically just 2 program maps, turbo and N/A. I think that once the choice is made for best ignition coil set up this will be used on everything, likewise on the choice of injector set up. The only other set up will be whether it is turbo or N/A. You might be able to go to lower flow rate injectors for N/A but that would be about it. As for the idle situation, if I need a valve for this I would probably go with the FIDLE type valve due to it's simplicity, I suspect it will trigger off of the water temp sensor that calls for rich fuel until it warms up then calls for normal fuel mix, this same output could trigger the FIDLE valve. I know the IDLE means just what it says, "idle" what the "F" stands for probably depends on how well it works (or not)

Tony
 
Hi Guys,

I've been reading too. They have at least 3 different models that are set up to make it easy for different sensors on the various engines.

We need to order the one that matches our engine's sensors as closely as possible.
Else we have to add on other 'car' manufacturers sensors and wire them to the board.

I need a list of the sensors we have on the engine and then I need to get the spec on each sensor example of things we need to know about the sensors.

1) Input polarities
2) do we have fuel injectors? If so are they low-impedance or high-impedance
3) IAC control or PWM

I would need part # and manufacture if possible for the sensors we have on each of your engines!

John,
just so you will have some ideal of what we are looking at.
The Weber engine has
coil over spark,Bosch ZS-L1 .73 ohms (diode protected secondary's)
fuel injection Bosch EV-6E 10-15ohms
4wire Lambda plus 2wires for the heating element,
IAC with 6wires, (stepper motor) 30 ohms
TPS .5 to .585
Turbo with 14.5 boost
Waste gate Solenoid Valve 23 ohms
Air Temp,
Air Pressure
Ambient Pressure, Intake temp. /pressure boost Bosch 261 230 099
Cam phase sensor (hall effect)
Crankshaft position sensor (AC signal generator)
Intake Manifold Pressure/Temp (MAP) Bosch 261 230 042
Boost pressure sensor Bosch 261 230 042
two wire Coolant Temp 3000-190 ohms
Knock sensor two wire.
Sequential injection with electric fuel pump 50. lbs pressure.
3 relays main, fuel pump, EFI.
 
Now that is what I needed!!!

OK the stepper motor is not hard to wire:
A six wire motor has a pair of wires for each winding like the four wire motor, but it also has a center-tap for each winding. It can be wired as either unipolar or bipolar. Use a meter to divide the wires into sets of three wires that have continuity to each other. Then identify the center taps. The resistance from the center tap to one of the end wires is half of the resistance between the end wires. To connect to a unipolar driver, use all six wires. For a bipolar driver, use only one end wire and one center tap of each winding. You can also use the full winding in bipolar mode at half the rated current, but the high speed torque will be reduced because it has four times the inductance of the half-winding configuration.
 
John

I think that once the smoke settles, there will be basically just 2 program maps, turbo and N/A. I think that once the choice is made for best ignition coil set up this will be used on everything, likewise on the choice of injector set up. The only other set up will be whether it is turbo or N/A. You might be able to go to lower flow rate injectors for N/A but that would be about it. As for the idle situation, if I need a valve for this I would probably go with the FIDLE type valve due to it's simplicity, I suspect it will trigger off of the water temp sensor that calls for rich fuel until it warms up then calls for normal fuel mix, this same output could trigger the FIDLE valve. I know the IDLE means just what it says, "idle" what the "F" stands for probably depends on how well it works (or not)

Tony

Tony,
your right, it does not have to be that complicated. The two engines will be about the same. Some different inputs for the Turbo. We just need to work through some basic information. If worst comes to worst just buy a ECU for the watercraft or RZ ATV.
I have not read anything to make me believe the Megasquirt 2 will not work
 
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I agree Mark just looked at it and the Megasquirt 2 is also twice the power, speed, and memory. in addition, the Fuel control has 1 µsec or 100 times more resolution than MegaSquirt-I = much finder control!
 
John,
just so you will have some ideal of what we are looking at.
The Weber engine has
coil over spark,Bosch ZS-L1 .73 ohms (diode protected secondary's)
fuel injection Bosch EV-6E 10-15ohms
4wire Lambda plus 2wires for the heating element,
IAC with 6wires, (stepper motor) 30 ohms
TPS .5 to .585
Turbo with 14.5 boost
Waste gate Solenoid Valve 23 ohms
Air Temp,
Air Pressure
Ambient Pressure, Intake temp. /pressure boost Bosch 261 230 099
Cam phase sensor (hall effect)
Crankshaft position sensor (AC signal generator)
Intake Manifold Pressure/Temp (MAP) Bosch 261 230 042
Boost pressure sensor Bosch 261 230 042
two wire Coolant Temp 3000-190 ohms
Knock sensor two wire.
Sequential injection with electric fuel pump 50. lbs pressure.
3 relays main, fuel pump, EFI.

Tony when you compare the above list what are your differences?
 
... If worst comes to worst just buy a ECU for the watercraft or RZ ATV.
...
I believe, if we can borrow a similar running machine I could just fly over and measure the sensors record the data and we would be done with the guess work.
 
Now reading the Megasquirt-II manual and to hook up the Megasquirt (only has 4 wires) as a bipolar stepper motor we are only going to use 4 of the wires or I'll need to make a H-bridge circuit to drive the stepper motor for both coils.
To wire for 4 wires using a 6 wire bipolar stepper we, use only one end wire and one center tap of each winding.

(ADDED) for the actual wiring see post #1070!

Then the instructions are easy:

Note that if you have the wiring connected incorrectly (or if you don't know how to wire it because it is an undocumented type), wire it up as best you can. Note that you will be able to tell which two wires connect to the same coil by the resistance across those two wires - the tap will be 1/2 the Ohms or about 30 to 50 Ohms if they are on the same coil, infinite otherwise. Then try the IAC. One of two things will happen:

1. The stepper motor does not work at all. In this case one of the coil windings has the wrong polarity. To correct this, switch the wires around on either of the coil windings to see if it helps (i.e., trade the connections of the two blue wires). If it doesn't help, switch those wires back and try switching the other winding's green wires.
2. The stepper motor works in reverse, i.e., it retracts when it should extend, and vice-versa. Reverse the wires so that the wires originally connected to:
* Coil 1, lead A is now connected to Coil 2, lead A,
* Coil 1, lead B is now connected to Coil 2, lead B,
* Coil 2, lead A is now connected to Coil 1, lead A,
* Coil 2, lead B is now connected to Coil 1, lead B.

PS:
This all seems pretty straight forward with instructions for a novice, it looks like more fun than work.
 
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Learned more about our stepper motor and Megasquirt-II we can:

1) simply run the center taps to the positive supply.

2) Then two ends of each winding are alternately grounded to reverse the direction of the field provided by that winding.

3) We'll use a (transistor) H-bridge circuit to ground the ends.

4) We'll also nee a small XOR logic circuit to keep both inputs from being seen as '1's by the transistors. Because with a certain combination of input values (both '1's) the result is that the power supply feeding the motor becomes shorted by the transistors. This could cause a situation where the transistors and/or power supply may be destroyed.
 
Hi John

Found the instructions on the MICROSQUIRT , will copy and mail today. Don't know how close they will be to the Megasquirt, should be close. The Megasquirt is about 3 time the size of the Microsquirt but has all the relays, drivers, and other heat generating devices in the same package, also can do IAC, as I recall both can do turbo or N/A.

On my N/A I do not see any kind of IAC, only a throttle idle adjustment screw on the throttle body shaft. Maybe the IAC was mounted remotely and a air hose went to the TB's, I only see on opening and that is for a sensor.

Tony

PS also mine came all assembled not a kit, I think you can get them both ways, but I had all the fun I want working with SMD soldering in the two way radios
 
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John , for me , if a "smooth" idle decrease was mandatory, I would look for a IAC unit that was PWM controlled or fabricate a simple FIDLE valve rather that make modes to the ECU. Remember the "old days" when you had a carb and in cold weather you would press the foot feed 2 or 3 times and start the car. Well the first press set the choke butterfly and the "stepped " cam on the throttle holding it open by the amount you adjusted on the fast idle speed screw that rode on that stepped cam. The "normal idle " was set with the "idle air bleed screw" only when the engine was warmed up. after the engine warmed up a "thermal spring" (heated by exhaust or electric resistor) would cause the "fast idle" cam to drop out but it dropped out "fast" when you applied the foot feed, not slowly like IAC, lived with it most of my life so will do it again.

Tony
 
In reviewing some post on the MicroSquirt forum there was a question about using a MicroSquirt on a older GM auto IAC. The answer was that the MicroSquirt does not contain a chip for IAC, only an output for a fast idle solenoid. Looking very closely at my wiring diagram on the "Walbro" ECU there is no IAC used, this is what I have on my REDLINE Weber engine, that why I could not find any location for a IAC. SOoooo units with a Walbro ECU apparently do not use a IAC, but it sounds like the Bosh ECU on the snow engine does. If you go to the MicroSquirt on the snow engine you will be using some form of fast idle cam on the throttle shaft operated by a solenoid or using a FIDLE valve operated by the same solenoid output signal. Don't see this as a major problem, just part of the experimenting process. I'm sure a solution will be designed and plans or parts available. If you must use the IAC then the "Megasquirt " will be needed, (a few bucks more)

Tony
 
MAN SOMEONE HAD BETTER GET THAT ONE, THE "FS" IS THE HARDEST SNOW ENGINE TO FIND !!!!!!!!!!!!!!!!

Call about the specs, miles , rebuild, harness, throttle bodies,ect

Thanks for the post Brent

Tony

PS. then call Randy at Watcon and inquire about any model notices that may be on that year and model of engine.
 
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You can probably get "up draft" intakes from Randy at Watcon, maybe even the TB's, not cheap but nice!!

You will want to make your own exhaust manifold anyway.

This thing "looks" new or rebuilt !

Tony
 
OK, trying to put together a trail to get you into the "good stuff" on the Microsquirt ECU. Have to go the long way around , don't know why but I do, so here goes.

Google www.microsquirt.com, this will take you to a page that has "Megasquirt your ride, which is the web site of www.diyautotune.com , click on this site, look down the left side of the home page and click on SUPPORT, when you get to the support page go down to near the bottom of the page and click on Microsquirt.com, this will put you on a Microsquirt forum, the first line on this page has a www.microsquirt.info click on this , when you get to this scroll down the page to line # 8 , there several choices to choose from, click on "wiring" now you have hit the mother load , enough infor to choke a horse.

Tony
 
Also have some parts info, Randy at www.watcon.com has a few sets of "up draft" intake manifolds " from low time "take offs" . He says he will take $305 for a pair (sell for $408) and he has throttle bodies used "take offs" for $500 a set (sell for $637 a set ) these are limited to in stock availability. New throttle position sensor is $ 90 .

Tony
 
Well, in my post #1071 I stated I did not see any IAC, well I have to eat a little crow now, after blowing up the schematic picture so I could read it better I DO SEE A IAC VALVE,-----------BUT !!!! it only has 2 leads to it and Randy has sent me some pictures of it and "at this time" it appears to be a FIDLE valve. It does not necessarily mount to the engine as it has 2 hose barbs on it which means it has a inlet hose and a outlet hose and can be remotely mounted , I think he quoted me a new one at $103.80 . With just 2 leads it should most likely be able to be operated by the Microsquirt, will most likely be either "on or off".

Tony
 
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Just recieved my Salvage FST Weber wiring harness from Emersons Snowmovile Parts in Mn. today and will start "gutting it" tomorrow for the connectors and leads that I need.

Will weigh the beginning and weigh the ending and take pictures.

Tony
 
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