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No spark to plugs


Ozzie831

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How's it goin?

Im working on my turbo-ed 77 280z and Im not sure where my spark is going :/

 

Im running megasquirt 2 v3.57, MSD 6AL, MSD Blaster 2 coil and a 83zx dizzy. I have good spark from the coil to the dizzy plug wire but it seems to go somewhere after that and its not to the plugs. I did the MSD test that checks the spark going to the dizzy from the coil spark plug wire. The one where you put the coil plug wire next to a ground and touch the white MSD wire to a ground to see if it makes a spark.

 

Ive had this problem before but I cant remember how I fixed it. I cant remember if it's an MS problem or a mechanical/wiring problem. I've turned the dizzy to different degrees to see if it was in the wrong place but there was no change. I have the RPM signal in tunerstudio while cranking so that is good. Ill attach my tune in case there is something wrong and I dont see it. Im not sure if the spark is just too weak but it looked good to me when I did the test (I dont know what a good or weak spark looks like but i could get a spark from a pretty good distance from a ground, about an inch or 2, when I did the test. I dont know if that constitutes a good spark or not but meh). 

 

 

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Just connect the wires the right way.  The point is that Megasquirt needs to tell the MSD box when to fire.  All that you've done is show that the MSD box will do that if controlled properly.  The fact that nothing is happening is an indication that MS is either not doing the controlling or that the MSD box and MS are not connected properly.

 

Chill out and understand out what the Megamanual is trying to tell you.  Then figure out how to make it happen.

 

 

By the way, "square wave" just means off-on with a set voltage in the on state.  Sounds more complicated than it is.  And, actually, if you look up the definition of square wave you'll see that what's happening isn't really a classic square wave anyway since the off and on periods aren't of the same duration.  It's really just a switching voltage from MS to the MSD box.  Just some trivia...

 

Anyway, in short, MSD isn't getting that switch from MS on the white wire, probably.

Edited by NewZed
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Alright so I got the car to turn over thanks to newzed's link. The problem was the way my car's wiring was previously set up with the MS1. On that set up I didnt use the Spark A wire on the Megasquirt generic harness but after looking at the link it shows that the MS2 uses that wire. I connected the Spark A wire to the white wire on the MSD like the link stated and Bam it attempted to start. The problem now is that I have to keep pumping the gas to keep the car alive. It wont idle, it will just start and die without me vigorously pumping the gas. Any suggestions on that one?

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When I downloaded tunerstudio the start and warm up enrichment settings were preset to a random car. So it is a possibility that it is the settings could be wrong. Im not a tuner by any means and I have no idea what they are supposed to be set at. Is there anything else that I can check while I wait for a buddy of mine to come over and check out the enrichment settings? Ive tried uploading my tune on here but for some reason it's not letting me, says i dont have permission to upload the file or something

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