Hey Muythaibxr, I've got a problem on my friend's Megasquirt I ver. 3.0.
First off, he's not getting an RPM signal.
I've been running my Megasquirt (same version--I ver 3.0) on my RX7 for the last year just fine. I just finished the full MS install on his 89 vert today but I'm having a problem picking up an RPM signal. So, here is the rundown:
When I hook MY MS up to HIS harness, the car starts and runs just fine. No problem. When I plugged HIS MS into MY car, It doesn't start at all. No rpm signal.
I already disassembled his ECU over a month ago and did the exact same thing to his as I did to mine with the "jumpers" added for the tachselect, v-rin, etc. stuff (I can't recall the names, but they are wired EXACTLY as mine are. The same goes for the resistors, LED's, etc. I also have the newest firmware downloaded and I even burnt my existing settings onto his ECU to try and start my car, but no luck. It powers up just fine, all the gauges on the screen work and all, but I'm just not getting an RPM signal at all.
My friend bought the ECU from someone who had it built at Glen's Garage. The label that is on the ECU basically states:
Options:
Input: VR sensor
Ignition output: High current direct coil drive
Idle air control type: Relay
Code version: (I upgraded this to 029y4)

When I had the ECU "apart", I took out those EXTRA wires that were put on the circuit board for the original setup, as well as taking out U3, R13, D1, D2, R43, C11, and C12.
The ONLY other differences I notice are that his regulator on U5 reads: LM2940T -5.0 P+ and Q2, Q4, Q19, and Q20 ALL READ PN2222A.
MY U5 says LM2937ET -5.0 and my Q4 and Q20 read PN2222A, my Q2 reads ZTX450, and myQ19 reads 2N3904.

These are the only other differences that I can find between his and mine now. Like I said, my MS works great on his car, but his does not. So, the wiring is ruled out. I'm really stumped now. Do you have any suggestions or tests that I can do? I would really appreciate it. Thanks.

Brian
P.S.: sorry for the long post

 

Also, both potentiometers are turned Fully counter-clockwise (they click)

 

do you have a stim? Sounds like one of the components in the VR conditioner might be busted. Typically, the op-amp, or the two transistors are the easiest to break in that circuit when putting the board together...

You can also check those transistors for solder bridges between the pins... Should be pretty easy to see.

They're the two transistors near the bottom of the board (the side opposite the heatsink), in the center.

 

I don't have a stim, but I'll check the board right now for any bridges on the transistors. Is there any way I can check the op-amp with a multimeter?
But yeah, as I said, I was hoping it was built well without any mistakes because it was assembled at Glen's Garage. Well, either way, I'll go check right now.

 

I'm checking some transistors right now and I'm wondering if there should be a "connection" (so to speak) with any of them. In other words, when I set my multimeter to the "connection" setting (it beeps when the 2 leads on the multimeter contact each other) I notice that on the BOTTOM side of the board on Q23, the 2 "leads" from the transistor that are soldered on the round parts on the board (not the square one) seem to be contacting somewhere (approximately 2.0 ohms). Q22 doesn't do this.
I'm saying this because I don't visually see any bridges on any of the transistors on the board

 

transistor might be fried ... try comparing that one to the same one on the working board.

Ken

 

muythaibxr, thanks for the help. Im the friend with the previously non-working ms. It ended up being that glen's garage placed one of the components with the polarities reversed.

 

Yeah, it turned out that R52 and R56 were switched (the VR sensors). It runs just fine now. I'm glad I noticed that , I'm just surprised that Glen's Garage could have put them in backwards like that.