MS3 with MS3X for Ford 5.0L EEC-V

[alex240]

Hi there. I recently started my project of swapping a 1997 Ford Explorer 5.0L into my 1992 nissan 240sx. I bought a MS3 DIY kit along with a MS3X card to handle the tuning side and plan on splicing the stock engine harness with the MS3 and MS3X harness using stock sensors/coils/etc. (except MAF- I want to use the MAP sensor on the MS3). I have had a pretty smooth time assembling the boards, starting with the Jimstim, the jimstimX, and finally the MS3. Anyway the main board currently looks like this:



Everything is done up to step 22 in the MS3X/V3.0 Hardware Guide. I am a little lost on the choices past this point (Q16? Spark Outputs section 5.3?). When I first started this project I thought it was an EDIS 8 system and was prepared to set up the board as such. Upon further research I found that the '97 explorer 5.0L is an EEC-V system where the coils are controlled from the ECU and so does not have an external EDIS module, mucking up my plan. Basically which optional components/jumpers do I need to install to get the Megasquirt to control the stock ford coils? Additionally where should I be looking in the guides for instructions if it is not an EDIS system? Any help is really appreciated!


Also here are the coils if that helps any:

[Matt Cramer]

Using a QuadSpark module is the easiest way to run that coil pack.

[elutionsdesign]

Yes, listen to Matt. You really didn't want that EDIS module in between anyway. Use your spark outputs A, B, C, D on the MS3X card.

[alex240]

Thanks guys. New question: testing the board I have 5 volt in all the right places on the U1 socket, but only 10.4v on Q5. Is this acceptable or an indication of a problem?

More importantly I am getting only 60 ohms of resistance on my two mica insulated components. The manual indicates there is a short and to replace the insulators. What could be shorting out that would be fixed by replacing the mica insulators? Or could there be a short somewhere else entirely?

P.s I jumped the CANL and CANH, could that cause any issues with testing?

[dontz125]

I have ... only 10.4v on Q5. Is this acceptable or an indication of a problem?

Q5 is the INJ2 driver. Between which two points are you measuring 10.4v? What is the measured voltage applied to the MS?

More importantly I am getting only 60 ohms of resistance on my two mica insulated components. The manual indicates there is a short and to replace the insulators. What could be shorting out that would be fixed by replacing the mica insulators? Or could there be a short somewhere else entirely?

Is the mica clean? Oils or certain chemicals can be conductive. While you should use thermal grease on the mica insulator, some thermal greases are conductive (we had a fellow describing that problem here a week or three ago). Are the threads of the plastic screws clean? Are there burrs from the heat sink bar drill holes poking through the insulator?

Q9 and Q12 are the active flyback transistors; pin 2 on each is connected to +12v. If the tab on these transistors is shorting to ground (the heat sink is grounded), then that could be your voltage drop at Q5.

P.s I jumped the CANL and CANH, could that cause any issues with testing?

Why would you do that? I don't know that it will cause any damage, but I wouldn't be surprised if it caused odd running behaviour.

[jsmcortina]

P.s I jumped the CANL and CANH, could that cause any issues with testing?

Why would you do that? I don't know that it will cause any damage, but I wouldn't be surprised if it caused odd running behaviour.

I think he was saying that he ran the jumper wires for CANH and CANL (ok!), not that he shorted them to each other. (not ok!)

James

[alex240]

Haha correct I have jumpered CANL to Js6 and CANH to Js8 per the instructions.

I am measuring 10.4v from one of the ground pads from the proto area to the left pin of U5. Not sure where else to measure on the board to reference this to.

I also just realized that the 61.4 I am getting is with the multimeter set to 200k mode. So that's actually 61,400 ohms? In which case I think I am good?

[dontz125]

Ok, that makes a lot more sense!

How are you powering the MS, and what is the applied voltage with and without the MS connected?

[alex240]

I am using a Jimstim plugged into the wall. The wall charger is reading 12.2v, pin 28 out of the jimstim shows 11.44v WITHOUT the Ms3 plugged in, and pin 28 on the megasquirt reads 11.41v when the megasquirt is plugged in. Getting 10.7v between ground in proto area and left pin of U5 still. So 0.7v drop, is this reasonable?