does anybody have a GOOD pic of the pullup resistors on the leds?

 

of the one on my board? ill go take one later

 

So your MS works perfectly in your friend's car, but no spark in your car?

 

look my car has no engine in it right now so im using a friends car to test the ms i built. its hard for me to tell if it flickers or not. and yes all 3 are on

 

So your situation is:

• You built the MS, and it has never worked
• You have not tested it on a stimulator
• You DO get RPM when you crank the engine
• You don't know whether the LEDs flicker when RPM is indicated
• You don't know whether your harness is wired correctly

Is that all correct? Anything else we should know?

 

i know the harness is working properly

 

When I say "harness", I mean everything past the DB-37 connector. Does your friend's car run with a Megasquirt? If so, is it a Megasquirt 1? If so, do you have the same firmware version and same msq loaded in your MS?

 

if you would have read through the first page it says im trying my ms on a friends car whos running a ms and yes they are both ms1 and were both built at the same time i am using the same firmware (dont think that really matter anyway) and yes i do know what a harness is. im not an idiot, i mean who the hell would try and plug in a stock rx7 harness into a ms they are completely different. i loaded his msq because i know his msq is tuned for his car and it is running just fine on his ms.

 

Actually, it's not that easy to tell whether or not you're an idiot, because you really haven't been communicating very well. No, you weren't clear that your friend is running a MS - certainly not clear that it's a MS1. You may be surprised to know that it's not terribly uncommon to use some kind of adapter to plug a MS into a stock harness. I've personally built a MS that plugs directly into the stock RX-7 harness. So when I ask a question like that, it's so that I might be able to help you when you didn't explain well enough what your situation is. I'm sure you are frustrated, but when you start blasting those that are trying to help you, you will quicly find the world a very lonely place.

So you're plugging your MS into a harness that your friend's MS uses, you're running the same firmware and the same msq, and you are getting RPM but no spark. That seems to rule out your settings and your CAS input as being the problem. That only leaves your spark output hardware as the problem. Those are pretty simple circuits. Did you install the pull-up resistors? Did you wire the LED signals to the proper DB-37 pins? The easiest way to troubleshoot it is with a stimulator and a meter or scope.

 

pull up resistors are in place and they are wired up just like my friends megasquirt.
i really should buy one of those i guess

 

well i had figured it was something to do with my spark hardware that's why i bought zeal board hoping to be able to bypass both vr circuits and just use the ones on the zeal board but apparently its harder then i thought.

 

Here's a good picture of the LED pullup resistors:

 

Thanks Aaron

 

I'm not familiar with the Zeal board, but it doesn't have spark output hardware on it, does it? You said you have an RPM indication in MegaTune or TunerStudio, right? That means the VR circuits are working (at least basically). Your problem seems to be spark output. How is the Zeal board involved with that?

 

yea i guess the spark output is my problem but i have no idea how to fix it

 

You don't need trailing spark to get the car running. For leading spark, you've got a single signal to figure out (D14). If you're going to test in the car disconnect the ignitors. Pull out the CPU. Are the LEDs off? Jumper pin 7 of the CPU socket to +5V. Does D14 turn on? Does the wire you installed for leading spark change between about 0V and about 5V when the LED turns on/off? If all that works OK your CPU might be bad. Have you swapped CPUs with your friend's MS? If it doesn't work as I described, you probably have a mistake in your construction. Maybe a solder short - those transistor pads are pretty close together. Triple check everything.

 

ill try swapping out the cpu

 

any updates? I'm having the same problem.

I have RPM but no spark and the middle LED blinks.

 

Have you tried looking at the timing with a timing light? Is it showing up right?

Ken