MSefi.com read only forum (Jan.15,2018)

If you are using a low impedance GM TBI, then most likely the injector are causing significant interference with the tach/ignition signal. See my post "Won't run need help troubleshooting".
John

It is definite the injector causing noise. But I still think it is effecting the ignition signal, and not the tach. If I limit the current to less than 15% the problem seems to go away. Also when I did the modify flyback circuit, it seem to go away. Unfortunately, I broke one of the transistor pins ...

Matt:
I might try that, but I do not think that my tach signal is the issue. As I have a GM TBI, which are low impedance injectors, I temporarly added a 10 ohm resistor (1/4 watt) to the circuit to make them "high impedance" and the ignition signal is now fine on the bench test. The car is put away ...

The files are located in the third entry of this thread viewtopic.php?f=89&t=40583.
John

Does anyone know which coolant sensor will work with Edelbrock intake? I bought a GM sensor, but it is 3/8 NPT and the Edelbrock looks to be 1/2 NPT. Any help would be appreciated.
John

I am still trying to solve me rough idle/ignition problem. I bought a better PC oscilloscope so that I could see the tracing better. I pulled the MS unit from the car and hooked it up to a spare distributor. I spun the distributor with a drill at about 900 rpm and saw a nice tach and ignition signal ...

I want to test my VR sensor signal before it goes into the module. I am going to pull my distributor and connect the VR wires to a circuit to see if the VR is functioning. Does anyone know of a simple circuit I could use to test the VR function as I assume the signal will need to be amplified if I ...

I have replace the module and the same thing happens. I have the tach cutting in and out about 1000 rpm, so I do not think senting 5 volts after 500 will solve my problems. Does anyone know what the actual tach signal looks like coming out of the module?

I continue to try and trouble shoot my issue. I have concluded that the basic problem is a poor tach input signal. The reason I came to this conclusion is that when I put 5 volts to the module I get a very erratic tach signal, which is caused by the Megasquirt having trouble deciding when to fire ...

Matt:
I just tried the alternate HEI mod as you described and there was no improvement. Any other thoughts?
John

I used these direction below:

It is so confusing, it is hard to know what to do next. They give some option if I am having problems with my tach signal, but I really don't understand them.

To install the Hall/optical input circuit (or points without a coil connection):

Install and solder R12 ...

I am using MS board V3. I have attached the msg and the log file. Unfortunately, the car runs so bad, that I can not keep it running to warm up. Therefore, I am not quite sure AFR is accurate as the unit may have not warmed up either. Although, I have the IAC motor all the way open, I have to give ...

I do not know my next step. I have a 1978 transam with GM TBI MS II version 2.905. I initially had it tuned without the Ignition and it ran fine. At that time the mechanically distributor was set at 18 degrees without vacuum and had 50 degree at idle with about 45 kPa of vacuum. The mechanical ...

OK. When I used mini term, I had wierd characters return when I type a "S". Therefore, I re-upload firmware version 2.905 and now it works. I do not know why, I didn't do anything differently. Now on to my ignition problems. Thanks for all the help.

Well, I tried to update to 2.9 to solve my problems. Things went as expected until step 10. Even though I have check my com port and speed to match, I can no longer connect to Megasquirt. For Tunerstudio, I do not see how to check to see if it using mtcfg.exe?
Any help would be appreciated.
John

TS version 1.13
MSII version 2.88
Injector Test Mode ask to select normal mode, test mode, or Repeat Test. I do not see any 12345??

John

It sounds like a simple question, but I can not turn off the injector test mode. I burn the controller for normal injector, but it does not take the command. Everytime I reboot it is in the test mode and I can not over write it. Any thoughts?
John

Thanks for the link. I have checked my wiring and it seems to be correct which is supported by the fact that the IAC fully retracts when the key is turned on. When I start the motor, it idles for about 30 seconds before you hear the IAC motor and the engine stall. If you pull the IAC, the pin is ...

I have been trying to get my IAC function to work. I have gone throught 2 IAC motor trying to understant this "simple" concept. I have a new IAC motor and to try and keep this simple I have set the start value at 160, the crank position to 0, and all of the temp table values to 0. When I turn the ...

I am running a Megasquirt v3 on my Transam with a GM TBI. The car starts fine, but will not idle. I pulled the AIC motor and it does not seem to work consistently. One time it shot the pin out. I got a new AIC and switch the coil leads, but it will not move. Is there a systematic way to test these ...