Misfire issues, narrowed down to MS I think

John L. · Post by **John L.** » Thu Jul 06, 2006 7:41 pm

You know I raced the car today and at the track it never gave me one hiccup that I can remember, but on the way back it hiccuped just cruising along like cutting the key off for a second, not even under any throttle, so it changes all the time and doesn't seem to correlate to air temps. IATs stay around 160 under boost which isn't bad for a stock IC with hardly any air flow to it.

It is a factory turbo engine, but I'm still running a little bit colder plug than stock. I've been entirely through the secondary ignition system with no change to the problem, and plugs gapped between .028 and .032 I think, doesn't seem to make any difference.

I blew the head gasket a little though, so it's still running but it needs to be changed before I do anymore, and I'm waiting on my LC-1 to get to Innovate and get it fixed up or replaced or whatever and back to me. Once I take care of that I'm going to run a wire straight from the battery back to the MS to see if I can get a clean power supply to it, my power still jumps all over the place under load, so that could still be part of the problem.

flylear45 · Post by **flylear45** » Mon Jul 10, 2006 4:57 am

John,

I, too have had the odd, random 'jerk' that comes usually at cruise and around 2500 rpm. I haven't logged it yet. It is totally unpredictable and cuts off my crise control when it happens. Hmm. I'm still running the old push-pull transistor ignition circuit,btw. I was thinking I have a grounding issue, but your situation makes me wonder if that's really the problem.

Wish I could be more help!

mxmang · Post by **mxmang** » Sat Jul 15, 2006 8:50 pm

im having this trouble with my ms2 v3 combo on my stock coil and using the igbt on my jetta... have we maybe found a problem with MS as a whole? please add me on AIM mxmang yahoo boredstoonguy or msn mxmang@hotmail.com .... we can have a chat about this

cossie_storm · Post by **cossie_storm** » Sun Jul 16, 2006 2:42 am

flylear:
I, too have had the odd, random 'jerk' that comes usually at cruise and around 2500 rpm. I haven't logged it yet. It is totally unpredictable and cuts off my crise control when it happens. Hmm. I'm still running the old push-pull transistor ignition circuit,btw. I was thinking I have a grounding issue, but your situation makes me wonder if that's really the problem.

This is the same problemt i have. have you found any fix 4 this?
i think i have tried about 6 different working msq, but no help.
it seems like the rpm drop 300-500 rpm or something
Anyone have any ideas about changing the size of the pullop resistor??
i will try this today, if this dosen't work, i will try edis or go for v3. card
have ms2 v.2.2 today.

John L. · Post by **John L.** » Sun Jul 16, 2006 10:03 pm

I have a V3 with MSnS-E and it sounds like my problem is very similar, the tach jumps when it misses sometimes, such as dropping 500 RPM like you said. It's not version specific, and I wouldn't think it's the code either, so I don't know what's going on. I'm really dumbfounded and no one seems to have any answers or suggestions as to what could cause it, it's a little frustrating, I've tried everything and the erratic ignition operation has cost me one headgasket already because the car sometimes detonates without me even knowing it. It seems to have sever spark scatter and mild spark cutout at times, which can cause missing sometimes and sometimes can cause detonation, yet other times it will run just perfect. Something's going to give or go before I run it at over 15 psi again, headgaskets are no fun to change and the race season is dwindling.

Also I put in a brand new TFI and PIP and the problem is still there.

cossie_storm · Post by **cossie_storm** » Mon Jul 17, 2006 4:03 am

John L:
What modification have you done to the board?
Have removec D8? have you tryied to change the resistor 1kohm with an bigger one?(the resistor that should be used in sted of d8?

I tried to change the resistor for the pullom, but did't work.
Does anyone have a schemtaic for the v2.2 bord?
my bord is not an original it seems

so don't know where the reisstor are

Post by **jsmcortina** » Mon Jul 17, 2006 5:37 am

cossie_storm wrote:my bord is not an original it seems :( so don't know where the reisstor are :(

Better check with your vendor then.

James

John L. · Post by **John L.** » Mon Jul 17, 2006 7:57 am

I have a 3.0 board with TFI mods done by the book, and based on all sources I have mine done correctly. I've rechecked all the components like the resistors for PIP input and even played with their value with no change to the problem it seems.

cossie_storm · Post by **cossie_storm** » Sun Jul 23, 2006 4:16 am

okay. i will try edis on my or try to change the outout 4 the spark driver.
meening use another led to drive the spark.. not sure how to wiring it yet..

John L. · Post by **John L.** » Thu Jul 27, 2006 9:08 am

Okay, ever since I turned off the accel enrichment all together, my problem has entirely gone away, why would this be? My TPS logs look perfect, I've never seen a spike in TPS or any noise over the line, even if the datalog didn't catch it, in all of the many logs I've run, you'd expect it to show up at least once or twice if there were noise or spikes. But my TPSacc variable is extremely messed up I think, although I don't understand it fully, I was getting TPSacc values on my logs like 499 and 599 and once even a spike out of nowhere that was like 1000000 or something like that, and at the same time I was getting negative spikes like to -799 and stuff like that. So I guess it could be the TPS but I doubt it, it could be high frequency noise from electrical interference maybe? Or else maybe a hardware problem with MS. I dunno, but the car runs fine with accel turned off, the only time I really notice is when I start it cold and mash the gas from idle. I may try MAPdot accel only to see how that does.

cossie_storm · Post by **cossie_storm** » Fri Aug 04, 2006 3:34 pm

I have tried to disable spark now, and it works well.
so i know there is something wrong with spark, i will try the old pull up surcit

flylear45 · Post by **flylear45** » Sun Aug 20, 2006 2:27 am

John, I'll try turning off Acc enrichment tomorrow, I'll let you know what happens

flylear45 · Post by **flylear45** » Tue Aug 22, 2006 3:41 am

I'm still getting tach jump and missing with both TPSdot and MAPdot accel.
Time to datalog to see what's happening.