I'm in the last phase of constructing the Megasquirt for my 74' 2.0L and I have some specific questions for anyone thats "been there, done that"

• Did anyone use the D8 diode for their 914, and if so, why?
• Resistors R4 & R7 can be changed to match the different coolant and air temp sensors. If I'm using stock sensors, what are the suggested resistor values for these?
• For the XG1 - XG2 jumper; was it necessary to change this so that XG1 jumpers to an external ground via X11?
• Was it necessary to increase the resistance value of R10 from the default 390 ohms?

So far everything has progessed nicely. The only glitch has been a bad POT on the stimulator, but its not a show-stopper.

Many thanks,

You want DNHunt, he has one that has been up & running for a few months. I think he is busy cleaning potting soil out of his longs.

He has a web site here:

http://www.geocities.com/dnhunt2002/Dave91...l?1054739433412

Do you still plan on running the web 73 with the megasquirt?

I am doing the same....

I found a D-shaft pot for the tps, am going to use the oem air temp sensor and head temp sensor.

My box is complete, relay box complete, just need to complete the harness and connector cable...

The project has taken a somewhat back seat to a new project..

1979 bmw 320I.....might be my next race car...but for now, daily driver...good luck, herb

Crash

Been busy gardening. Removed at least 50 lbs of dirt from the car when I had it steam cleaned.

I jumpered D8 and used the supplied R10 390 ohm. These are part of the tach signal input and people have had to tune this signal to get the Megasquirt to trigger. My tach signal is off of an MSD tach adapter so it is not stock. Still build it per instructions and try it. More likely than not it will work fine and you won't need to change R10 or cut the jumperon D8.

Use the supplied R4 and R7, then run Easytherm4 to provide a software correction for the stock sensors or include the .inc files if you burn a new chip. Check my page I think I have those files there.

The ground issue is something new to me. I suspect mine is grounded on the board but I don't know for sure.

Way to go, you're close now

Dave

I used GM sensors on mine, so no need to change anything.......

Congrats, we like to see more of this going on

ChrisReale: Yes I am. The WEB 73 is the main reason for going to the MS. Its supposed to be stock FI compatible, but I've found that my setup does not provide sufficient adjustment across the operating temp range. Ned something more programmable.

Herb: Shame on you! You're lettin a Teener take back seat to a bimmer? Did you get to the installation? I'm planning on locating the ECU under passenger seat - hope it fits.

Thanks Mueller. Is yours up and running? Like to here more about it.

Dave: I was hoping to get your files. Do you know what temp values you used from the sensors when creating them (a min of 3 vals req'd)? The reason I ask is that I've noticed identical stock parts output variations in signal. SO I'd like to compare your sensor values to my stock sensors and make sure they match.

Also Dave, you mention in you Files URL that someone could use your files with a stock programmed CPU (& 6-ohm/10watt res) - did I understand that correctly, or do I need to bribe, plead, beg you to program mine?

If I were to send you the $$$ + shipping cost, would you be willing to pickup another set of the 6-ohm/10-watt resistors for me? Local radioshack don't have em.

Thanks all,

I'll run down and see if they have any and let you know. the resistors are used instead of Pulse width modulation. I used a Hi res code which excludes PWM therefor I needed the resistors. I'd be glad to program a chip or two for you, just let me know.

Dave

digikey.com
mouser.com

you can buy your resisters on-line at this two above places.

i ran the MS for a few weeks before breaking an exhaust stud......since then, the motor has been sitting on my work bench (a year I think)

Car ran great, it was too lean at first, but I was not running an 02 sensor.
I dyno'd it right before I pulled the motor, I got 76hp at the rear wheels on a stock 2.0, I should have been able to squeeze more out of it, but I had other problems with the engine

Mueller: You must have a Big work bench. So how have you been handling the "withdrawl" symptoms - or do you have another teener to drive?

I also looked at both those sights, but couldn't find Resistors that can be mounted free-standing, since the MS board doesn't account for them.

Dave: Thanks for the offer. I'll be getting back with you. But should the chip even need programming? If I use your files and the resistors, what needs to be different on the processor? Hope I'm not missing something here!

Regards,

Gerard

To run my stuff without changing the fuel map you need to run the same setup I have. The resistors, Hi res code and fuel map are all related. The Hi res code (controls injector pulse width to .01 msec instead of .1 msec) eliminated pulse width modulation ( the onboard method of controlling current to low impedence injector) therefore, resistors in series with the injectors are needed to control current. The resistors slow down opening time and so the fuel curve would be too rich for the stock code. It would however provide a very good start for tuning.

Dave