Fet Method Issues

[MegamanSc400]

Can Someone Point Me In The Right Direction .I Have A Megasquirt 2 V3.57 .I Had To Build Ignition Inputs Using FET Method .When I Connect FET Method To 5v I Have No Power Through The Megasquirt .But When FET Method Is Disconnected I Have 5v And .What Could Be Going Wrong

[bobxyz]

Are you using this diagram and a small extra prototype board? http://www.msextra.com/doc/pdf/html/MS2 ... .4-77.html

How many spark outputs are you building 2, 4, or 6? What are you using for power? (I think the "Proto 5V" and "S12C" signals are the names for the V3.00 PCB)

In the above diagram, the Spark A, Spark B, Spark C, Spark D signals are the new FET buffered signals. They need to go to unused pins on the DB-37 or DB-15 connector. If you connect them to something that's already used, it might short out the 5volt supply. Can you post a picture of your new wiring diagram, or of your modified PCB?

[MegamanSc400]

I Used That Diagram And It Was Spark A B C And D I Was Building .I Have Since Removed The Fet Method .After I Removed It I Was Able To Get Communication.But Now I’m Only Getting Communication With The Boot Jumper Connected .If I Remove The Boot Jumper The ECU Powers Up ,But D14,D15,And D16 Flash Constantly,My Injectors Constantly Pulse But I’m Not Getting Communication To The Computer Anymore.Only Communication Now Is With Boot Loader Jumpered

[rickb794]

At first something in your Mod was pulling down the 5v that is why it would not come alive.

Now it sounds like you have some sort of ground loop?
or an output is influencing the crank signal.

[MegamanSc400]

Sounds Like A Group Loop Or Something.Idk Where To Start Looking Though

[bobxyz]

Try reloading firmware with the boot jumper installed. If that doesn't help, carefully inspect all the locations that you've added wires with a bright light and a magnifying glass. You're looking for something that is accidentally shorted to an adjacent signal.

[MegamanSc400]

Ok Will Definitely Check That Because I Reinstalled Firmware And Same Issue Is Happening.Ill Get Back With An Update Soon

[bobxyz]

One more thought - what other circuits and sensors do you have connected to +5V ? Maybe one of these is near to overloading +5V and when the MS starts to run, it's enough to reset the MS or temporarily trip the poly fuse. You may be able to see this if you connect a voltmeter to +5V while it's misbehaving.

[MegamanSc400]

My Cam Sensor Circuit Was Built Via Ground Switching Which Uses 5v .And Of Course My TPS Uses The 5vRef Wire

[MegamanSc400]

Anybody Got A Jimstim For Sale Around Georgia ?Im Tired Of Testing This ECU Inside My Car .Btw I’m Getting 5v In All The Right Places .My Only Concern Is zo’n The 12v Side Of U5 I’m Only Getting 9v .I Would Guess There’s A Problem There