Megasquirt starts, then dies...
08-31-12, 01:47 PM
#1
starts, then dies...
So I'm attaching a copy of my log... the car starts fine, smoothly revs to about 3K, then dies.
The strange thing is that it actually idles (albeit poorly) without the MAP sensor connected, which leads me to believe it is related to that.
I've never gotten a reply in this section yet... but this time I really need help. Thanks in advance!
The strange thing is that it actually idles (albeit poorly) without the MAP sensor connected, which leads me to believe it is related to that.
I've never gotten a reply in this section yet... but this time I really need help. Thanks in advance!
09-02-12, 10:22 AM
#7
Engine, Not Motor
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I can't open your tune (unzips to a file "current tune" with no extension, TunerStudio opens it and nothing happens) but I'd guess based on your description that the VE table is too lean. Assuming all other settings are correct.
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09-02-12, 11:07 AM
#8
Heh... so heres an update.
I got pissed off with the settings I was given (for free, so I cant be too mad
) So I went back to square 1 with Aaron's settings/tables. Fired and idled on the first crank. Should have done that in the first place. Even with the MAP vacuum tube plugged in... and the BAC plugged in.
But for some reason my dash tach is reading 1000 rpms above what the MS is seeing... and I know that the MS is right.
Gotta say thanks to DIY Autotune for distributing an excellent product, and everyone else involved in making something like this happen. Aaron, thanks for the writeup. I didn't use the whole thing, but you are the one that ended up getting me through it.
I got pissed off with the settings I was given (for free, so I cant be too mad
) So I went back to square 1 with Aaron's settings/tables. Fired and idled on the first crank. Should have done that in the first place. Even with the MAP vacuum tube plugged in... and the BAC plugged in.But for some reason my dash tach is reading 1000 rpms above what the MS is seeing... and I know that the MS is right.
Gotta say thanks to DIY Autotune for distributing an excellent product, and everyone else involved in making something like this happen. Aaron, thanks for the writeup. I didn't use the whole thing, but you are the one that ended up getting me through it.
09-16-12, 10:17 AM
#12
Engine, Not Motor
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The tach pulse should come from the trailing coil. Yellow/blue wire.
If the tach is reading twice the actual RPM of the engine, the coil is firing twice as often. Reversed coil connections?
If the tach is reading twice the actual RPM of the engine, the coil is firing twice as often. Reversed coil connections?
09-19-12, 05:38 AM
#13
That wire is obviously unmolested when installing the MS.
I think this might be a bad ground. There isn't any linearity to the curve... it idles at more or less the correct position, but when cruising at around 2000 rpm, the tach is reading over/at 6000 rpm. I think I'm going to add a ground at the back of the cluster and see if that helps.
09-25-12, 10:22 PM
#15
So here's an update, I ran another ground from the tach harness to ground, but no solution... then a few seconds ago I thought about it a little more.
The tach is generally double the actual RPMs... and the trailing triggers are both somewhat near the tach input blue/yellow wire... maybe its picking up both of those triggers as noise - wouldn't that cause a double (sometimes triple) RPM reading?
Tomorrow I'll shield both of those wires with foil/shrink wrap and see what happens.
The tach is generally double the actual RPMs... and the trailing triggers are both somewhat near the tach input blue/yellow wire... maybe its picking up both of those triggers as noise - wouldn't that cause a double (sometimes triple) RPM reading?
Tomorrow I'll shield both of those wires with foil/shrink wrap and see what happens.
09-30-12, 10:33 AM
#21
MS2 v3.0 board... using tunerstudioMS 2.0.5 and firmware is 3.1.0
Another question is on WUE, that light is always green... even after it passes the last point on the graph, it stays in WUE mode. Havent seen a setting for the WUE range... weird.
Another question is on WUE, that light is always green... even after it passes the last point on the graph, it stays in WUE mode. Havent seen a setting for the WUE range... weird.
10-01-12, 11:39 AM
#24
Try unplugging the secondary coil and lock timing and check the leading plugs with a timing light. I don't see how you could have switched the leading and trailing wires and it still run ok. If you can get a hold of a scope and current clamp you can check all your plug wires and make sure they are correct (pri is wasted spark, sec is coil select). If that is correct you could try connecting the tach from the sec. coil and use the megasquirt tach output. If megasquit is reading engine speed correctly that would allow you to see if anything is wonky with your gauge cluster.
10-01-12, 11:44 AM
#25
thats what I was thinking too... the car actually runs fairly perfectly except for the tune. I drove it 60 miles to a show and back this weekend and really enjoyed it.
I really dont think its a wiring issue... it just runs too well, and the tunerstudioMS RPM readings are dead on.
The plug wires are brand new NGKs and even with the old NGKs it was doing the same thing. It has to be something in the ignition settings.
I really dont think its a wiring issue... it just runs too well, and the tunerstudioMS RPM readings are dead on.
The plug wires are brand new NGKs and even with the old NGKs it was doing the same thing. It has to be something in the ignition settings.