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Serious VEMS Trigger Issues

Posted: Sat Jan 23, 2016 4:10 pm
by vt10vt
So quick back story. A couple weeks ago the car started doing this thing where it would die during warmup. I never logged it ( :bangshead: ) or really worried about it as it's been too cold and I've been too busy. Then a few days ago it started getting harder to start in the mornings, requiring a couple key cycles. Then yesterday it barely started and ran on 1 or 2 cylinders for a minute, died, restarted same way, required foot to keep it running, and then started running on all cylinders after a few minutes. Today it won't start. At all. I tried disabling the cam sensor in VEMS and taking the 50/50 shot at it starting, no dice after plenty of tries. Cam sensor seemed to be bad, I replaced it, new one seems to test out fine, nice 0-4.9v swing but still no start.

Attached is a trigger log, PLEASE HELP I'm about out of ideas and really don't know where to go from here in terms of diagnostics. The crank signal looks normal but I don't understand why I'm getting a.) 2x cam sync pulses and b.) I'm getting so many secondary trigger errors. Any help would be appreciated!

Config and other trigger logs attached in following posts.

Re: Serious VEMS Trigger Issues

Posted: Sat Jan 23, 2016 4:11 pm
by vt10vt
Config

Re: Serious VEMS Trigger Issues

Posted: Sat Jan 23, 2016 4:11 pm
by vt10vt
Trigger log with cam sensor disabled

Re: Serious VEMS Trigger Issues

Posted: Sat Jan 23, 2016 5:50 pm
by vt10vt
Should have mentioned: 1.8T w/ OEM 60-2 on the crank and AEB single window cam wheel (1 window). Econoseal VEMS wired into factory harness, COP w/ R8 coils.

Re: Serious VEMS Trigger Issues

Posted: Sun Jan 24, 2016 3:18 am
by themagellan
Free bump.

It's been cold as stück around us and I can only imagine e VT. If you've been driving through slush or weather has been brutal why not check your harness or wiring that controls the coils/injectors if you didn't touch anything then something touched itself

Re: Serious VEMS Trigger Issues

Posted: Sun Jan 24, 2016 8:24 am
by chaloux
This is a shot in the dark, try enabling hall dirac filtering in secondary trigger settings. I had major issues with the 4k a few iterations back and enabling this made all my starting problems go away... Might help.

But I think it was because I had grounding issues to the ECU.

Re: Serious VEMS Trigger Issues

Posted: Sun Jan 24, 2016 8:47 am
by vt10vt
Thanks guys!!

Mage, I've cleaned all my connections and checked grounds etc, I have power everywhere, seems like a trigger issue to me. And yeah I'm done with winter!

Matt, I've tried it with the filler, didn't seem to make any difference but I'll give it another shot. As soon as the car gets any amount of heat in it, the problem goes away. I've checked/verified my grounds.

Please keep the suggestions rolling it'd be great not to have to ride the bus in tomorrow!

Re: Serious VEMS Trigger Issues

Posted: Sun Jan 24, 2016 12:25 pm
by Marc
I remember when you were up your battery was shot. have you replaced it? winter means slow cranking as it is. with a shit battery? probably enough to make a no start situation.

Re: Serious VEMS Trigger Issues

Posted: Sun Jan 24, 2016 12:27 pm
by vt10vt
Marc wrote:I remember when you were up your battery was shot. have you replaced it? winter means slow cranking as it is. with a shit battery? probably enough to make a no start situation.

Nope fresh battery and I'm keeping it on a charger while I work and it cranks plenty fast.

Re: Serious VEMS Trigger Issues

Posted: Sun Jan 24, 2016 12:36 pm
by vt10vt
What I really don't understand is why I can't get it started without the cam sync. By all accounts that trigger log looks perfect to me :nuts:

Re: Serious VEMS Trigger Issues

Posted: Sun Jan 24, 2016 12:38 pm
by vt10vt
Trigger log with Hall Direc filtering enabled.

Re: Serious VEMS Trigger Issues

Posted: Sun Jan 24, 2016 12:58 pm
by Marc
you're getting two pulses on the secondary, not sure why but its easy to filter.

on the secondary trigger page, set ignore sectrig pulses above = 20.

if you really want wasted spark to work properly, you have to set dual output mode on the ignition outputs and set the channels to the cylinders that are 180 out, and disable the secondary trigger.

Re: Serious VEMS Trigger Issues

Posted: Sun Jan 24, 2016 1:12 pm
by vt10vt
I don't want to run wasted spark, just trying to diagnose things :)

Fresh set of plugs got it running without the cam sync, tried filtering like you said Marc and although the trigger log (attached) seems okay I still get no start.

Re: Serious VEMS Trigger Issues

Posted: Sun Jan 24, 2016 1:14 pm
by vt10vt
Wait, take that back, just started immediately with those same settings... maybe I forgot to cycle the key? I feel like I'm going :nuts:

Re: Serious VEMS Trigger Issues

Posted: Sun Jan 24, 2016 1:22 pm
by vt10vt
Still getting "Less Second Trig" on the main display

Re: Serious VEMS Trigger Issues

Posted: Sun Jan 24, 2016 1:23 pm
by vt10vt
Super quick log of how it's idling now

Re: Serious VEMS Trigger Issues

Posted: Sun Jan 24, 2016 1:55 pm
by Marc
your primary is going haywire with the engine running which usually means noise. check your plugs, coils, and grounds.

Re: Serious VEMS Trigger Issues

Posted: Sun Jan 24, 2016 2:23 pm
by chaloux
Running resistor plugs or no? Running non-resistor plugs in my 4k would make it shut down after a pull as soon as I lifted off throttle. Put resistor plugs back in and no problems.

Re: Serious VEMS Trigger Issues

Posted: Sun Jan 24, 2016 2:58 pm
by vt10vt
Running NGK 4554, but I do have questionable coils, I bet that's the problem. It does the same exact thing with two different crank sensors and I feel pretty good about my ground arrangement. It's a non-issue after it gets some heat in it so I bet it's something with the coil's insulation or something that is susceptible to the cold. I guess I'll be ordering a set of new coils tomorrow, I have piles of used ones but so many of them exhibit weird issues I should definitely just do all four to eliminate that as a possibility :shame:

Re: Serious VEMS Trigger Issues

Posted: Sun Jan 24, 2016 3:09 pm
by vt10vt
Is this my primary trigger going away completely or am I interpreting this wrong?