ok guys i was wondering if the fc igniton coils are fired by means of +5 v
on the stock ecu , and the ms uses - trigger at the output would that cause it to
fire a little late because the reason it works is because of the led is pulling it to +5
after the transistor closes the - to the led the reason i ask is because the spark is really weak at crank right now im taking the transistor from the stock ecu and making a diferent circuit to see if it works better any sugestions

i was thinking to remove the leds and place the base of a npn transistor and have it switch a 5v signal the the ignitor with a 150 ohm resistor between the ignitor and the npn output and also the diode from the pnp collector to emitter.

ill try this tomorrow and see if i get a stronger spark

 

ok i did the project it works great and i dont need the leds the only problem is that i cant get it to fire while cranking but if i turn the cas with my hand it fires right up but this has been the problem since day one i still cant figureit out any ideas

 

got it !!!!!!!! the problem was in the stock cas harnes , my best guess is that when u crank the stock harnes is together with the power wire to the starter and i guess the magnetic field created by the cranking interfer with the cas signal, so what i did i ran a whole new cas harnes around by the driver side and it cranked right up , the stock transistor and setup from a turbo or na ecu work real good, i think the reason is because the ms fires it interups the led by pulling it to gorund and after the led turns off it goes high
and that is when it fires causing it to fire late. i dont know if maybe it was set up like that for dwell or something but with the new diagram i made it works fine without the led.

 

It doesn't fire late at or anything like that... I've measured it on my oscilloscope....

If it was firing late or was weak, you may have set up your cranking advance wrong causing a weak spark.

 

well i might have been but i wasnt geting spark at all while cranking unless i push started and i now for a fact it was because of the cranking, maybe creating a magnetic field while cranking plus the cas harness is together with hot to the starter at one point in the harness because as soon as i separated it started in the first turn. but i still dont understand why the stock ecu trigers the coils with a npn transistor and the ms with a pnp i mean i understand that when the transisitor closes it the lead goes high and that when it fires i guess thats why i tought it fired late i dont mean very late i mean nano seconds which i now doesnt mater but with a npn u dont need the leds or the pull resistors

 

Some friendly advice - ignore it if you wish, but understand the consequences. It would be SO much easier to understand what you're saying if you could find a way to use periods and capital letters. Maybe even an occasional comma or a paragraph break. Many people won't even finish reading your post because it's so hard to follow. If you want a response, try using something a little closer to English.

 

Ahmen!

 

Well sorry about the slopy writing but i get lazy. Anyways i built the circuit from a sock ecu
and now i dont have any problems starting the car, before i could not get it to fire while cranking i would have to push start the car. I wish i knew how to post bmp files,
i have some drawings of the circuit before and after.

I dont mean to be negative or anything, im just trying to help, i've read somany post on people not geting spark at crank. Sorry if i ofended anyone.

 

No offense, not feeling negative, etc, etc. Just trying to make it easier for all of us to help you, and for you to help someone else.

 

Not getting any spark during crank can be MANY things...

If you're not getting rpms displayed in megatune, you won't get spark... If you don't have the wheel decoder and crank advance and trigger angle all set up right, you could get weak spark or no spark on crank... etc.... And yes, noise from an old starter can cause it too.

As far as the spark output circuit, NOBODY has posted problems with that, which makes me think you had something else set up wrong.

 

I had similar problems when I initially set up my car, It would not pick up rpms when cranking. I regrounded everything to the engine block instead of the chassis and it cured this problem.

Kris