MS2 DIS Saturn files for OBD1 code2.6

S.Bretz · Post by **S.Bretz** » Fri Sep 15, 2006 8:13 pm

Ian says its there.

And mine is getting quite worse....especially with the boost turned up more. It used to pull harder with timing advance, now it pull harder with in limp mode. Under high boost sometimes it just misfires and then you can hear it drop a cylinder or 2 until it either runs the fuel out (too much from not bunring) or the ICM gets back to doing what it should. I know it works some what because I can tunr the advance off at idle and the rpms drops...it just seems likeit doens' have the ball to light up the mixture under haevier loads, richer modes (11's) and antything leaner then the 15.5 range...some times it will run with 15.5-16's, butmost of the time it will misfire for a second and then come back. If I turn advacne off, I don't get the stumbles...but its just slow and I have to burry my foot into the gas pedal more to get it to move.

Lordprimate · Post by **Lordprimate** » Sat Sep 16, 2006 9:02 pm

well i tweeked my .ini file so i can drop my dwell to zero.

after fiddeling around this is what i noticed...

anything below .5ms Dwell time caused popping and the car to die... very suttle at .4-.3 ms and at .2-.1 ms the car dies quickly..

from 1 ms to 25.5 ms i cannot HEAR or FEEL a smoother or stronger idle it all seems the same...

i did notice that if you ramp up the dwell time it changes more... IE .. Varies about 1ms around 25.5... maybe 2ms ... but if its on 1 ms it only varies .1-.2 ms everyonce and a while.

hmmmmmmm

bluetrepidation · Post by **bluetrepidation** » Sun Sep 17, 2006 6:56 am

Well having dwell under .5 ms I'd expect that to happen. The signal with those setting switches on and off so quickly the ICM may not be able to get a good read and it wold be more likely prone to interference. When you are changing the dwell and spark duration what you are actually doing is changing the duty cycle of the square wave the ICM receives. The ICM controls dwell with it own logic. This is why I'm confused that making changes to dwell is helping some people's setups when it really shouldn't do anything unless the duty cycle is so short that the signal gets misinterpreted.

A.J.

S.Bretz · Post by **S.Bretz** » Mon Sep 18, 2006 1:09 pm

IDK. I'm at a point where I might just dump this hole MS BS and get something that works. I went to the yard today to pull an ICM off another car, and it only has 4 wires... apparently, the PCM does all the other stuff and sends out an Ign"A" and Ign"B" signal. It would be the LX-367 module that is in the standard motor products catalog...an then there is a LX366, that doesn't even have tabs to put an ingtion coil on it....Im just lost righ now and want to shoot the MS and the car.

bluetrepidation · Post by **bluetrepidation** » Mon Sep 18, 2006 1:54 pm

Well I know how you feel considering I had lots of problems with the IAC till it was fixed. Let me ask you this...... Are you using stock plugs and wires? If not what? Also, how is your ignition output on your MS internally wired? Directly to the processor port or through the high current ignition driver?

A.J.

S.Bretz · Post by **S.Bretz** » Mon Sep 18, 2006 3:52 pm

I don't kow how its wired...I just followed the instructions for the HEI/DIS like the guide says.

More insight. I was looking into get a direct ignition from electromotive, and I looked into the PDF manual...it said that if you don't use resistor wires, then use a resistor type plug to eliminate/reduce noise...well I have used a regualr copper core plug for years with no problems...so I decided to get a set of resistor plugs. I installed them and I can turn the dweel and spark duration up to 25s an it won't stall out...and I can give it a load and it doesn't miss fire. I did manage to do a high boost pull in second gear, but if it was still breaking up, I couldn't tell. I will have to wait till tomorrow when I get on the express way, I mean test track, and can do a 3rd gear pull, 4th it out of the question, thats around 150ish at 7k.

I really hope the plugs are the problem...its usually stupid stuff that pwns me, and plugs seem like a pretty stupid thing right about now. If it turns out being the plugs, I'm gonna feel pretty de-de-dee, but releaved.

bluetrepidation · Post by **bluetrepidation** » Mon Sep 18, 2006 5:51 pm

I hope it is the plugs. You need resistance in the plugs and wires or the current on spark can get very very high and burn up coils or ICMs. So this seems to fit your discription.

A.J.

S.Bretz · Post by **S.Bretz** » Tue Sep 19, 2006 6:04 am

Yeah, it doesn..but it doesn't explain why I coud use a regular plug for so long. I have been using them for 200K plus now with no problems. It wasn't until the MS timing when I started burn stuff....weird.

Well. Im of to school. I let you know how things go later today.

S.Bretz · Post by **S.Bretz** » Tue Sep 19, 2006 11:35 am

Well, it did pul threw the 6900-7000 barrier on high boost today...before it would stop like it was at a wall, and it has been getting progressively worse. So being able to go past 7K is good news, but it was still breaking up. I'm going to get another saturn ICM tomorrow and see if that helps....if the problem has been getting worse, then I think it is safe to asseme that the ICM may have been getting worse and worse with the NON resistor plugs. More updates tomorrow night.

bluetrepidation · Post by **bluetrepidation** » Wed Sep 20, 2006 3:01 pm

Well if it work on stock I agree there shouldn't be an issue. But until it is pinpointed I'd stick with resistor plugs. Small sacrifice for not having to replace a ICM over and over.

As for the real issue I'm nut sure where to check next. I think we need to get one of the pro's attention to this thread to offer advice. *Waves huge red flag*

A.J.

S.Bretz · Post by **S.Bretz** » Sat Sep 23, 2006 3:54 pm

I think I'm makeing some head way. I'll try out the new stuff tonight. It sunds like I have the timing set right (its not suttering and popping), but it sounds like the it has weak coil fire. I'm gonna mess with some spr-duration and see if the coil is just loosing it charge. ...It only does it in lower rpm when it can apply a longer spark duration time, above 2-2.5K, the "weak fire" sounds starts to go away.

If I'm right, then the saturn DIS uses differnt input capture then what the manaul says GM DIS uses.

I'll update asap.

bluetrepidation · Post by **bluetrepidation** » Sun Sep 24, 2006 12:26 pm

I changed my dwell and spark duration back to 25.5 ms after running at 1 ms for a month. I still can't tell any difference in performance.

I would like to scope a stock Saturn DIS setup to see what is really going on but unfortunately my neighbor with a OBD I Saturn just moved.

A.J.

S.Bretz · Post by **S.Bretz** » Sun Sep 24, 2006 2:14 pm

Well.I just a bunch of testing. And service manual reading.

I changed the ingtion capture from Rising edge to falling edge, as the Saturn DIS madole picks it up from the rise when it goes past the sync.

I then changed to -70* for the carnk offset. The factory manual says the sync is 70 after TDC.But that didn't work so well..it ran but just bearly. Set the entireign mapto _0_ degrees and I happpend to get the timeing light and look before it stalled out....it was around 60-70 degrees advance.So I dropped the offsetto 0 and the idle improved a bunch. I checked the advance and it was at 10 degrees, so I setthe offsetto 10degrees and it was happy (tdc mark on the coverwas lined up with the crank pulley). So I loaded my mapbackin and strarted playing. RIght away I noticed it ran alot smoother.

I drove around for about an hour and if feels alot better under a load. I didn't feel it breaking up at 17psi....I'll do a couple of puls tomorrow at around 20 psi in 3rd and see if I can feel any difference...in 3rd at around 18 psi, it wouldn't go past 6800-7000 rpm....and in second gear at the same spot, it would breakup and feel like I was pulling a parachute....then it got more betterrerr at 7200. WIth the test pulls today, I didn't feel any problems in second gear, but I want to make a 3rd gear pull before I'm saticfied.

What I don';t understand though, is why when then service manual says a sync pulse is at 70 ATDC, then why do I need to put in 10 BTDC to have the MS sync up with the crank...that;s 80 degrees. A really big differnce.

S.Bretz · Post by **S.Bretz** » Mon Sep 25, 2006 8:54 am

Still breaks up. I'm really startying to hate this stupid thing.

bluetrepidation · Post by **bluetrepidation** » Mon Sep 25, 2006 2:05 pm

You know what I just saw this.......

http://www.megamanual.com/ms2/inputHEI.htm

Maybe it is time to try out the first mod. It is so simple anyhow. Maybe the signal is weak so at high RPM the MS isn't getting a clean signal. Of course you would notice this in the RPM when datalogging but maybe not.

A.J.

S.Bretz · Post by **S.Bretz** » Mon Sep 25, 2006 3:56 pm

RPM stays stable in datalogs...so spikes, dips to jumps.

I played with it some more this afternoon on the way to my afternoon class. I went on a hunch and got some kinds positve results. I had the trippger off set set to 10BTDC, so I dropped that to zero (advanced it 10 degrees) and then dropped the entire timing advance table by 10 degrees. The problem didn't happen at 6800, but instead it was pushed further north in the RPM around 7200-7400ish. When I done with work tomorrow, I'll play with it with my timing light. I was gonna stop by and pick it up so I could play with it tonight, but its a little too load to play with this late....my neighbors aren't Neck enough to tolerate that kind of stuff.

Edit: Side note. I just found out what trigger mask does. I will try to play with it a bit. I haven't touched it since I had no Idea what it was. I figured it must be for trigger wheel people since I didn't see it in the 2.33, but it was there in 2.68. SO I'll see it I'm getting and coil ring.

as anyone played with that? What are your mask times like? 1ms, 5ms...10ms?

bluetrepidation · Post by **bluetrepidation** » Wed Sep 27, 2006 1:31 pm

S.Bretz,

Hey I just dropped off my last disgusting Saturn engine to my engine builder. I was showing him my MS setup and he has a buddy running a big old honken turbo on a Pontiac that used to be supercharged. I guess his buddy wanted some more info on the MS since he wants standalone too. Anyhow I mentioned how some people where running 21 psi boost on a Saturn block and he was quite impressed. Especially since he was familiar with the way Saturn casts their blocks. I mentioned that you where getting breakup at high boost/rpm and he wasn't really surprised. At those pressures he said you really need to upgrade your ignition. He runs dirt track cars running 15:1 compression and you just need to upgrade the ignition at that point. So it may be time for some coil on plug action.

A.J.

S.Bretz · Post by **S.Bretz** » Wed Sep 27, 2006 4:08 pm

Ok...let me say this. When I run limp mode>no signal from the MS< the ignition stay strong. I have run it up to around 25-26 psi and it was smooth...just a little slower. I can turn the MS back on, and run limp mode timing numbers, and it breaks up. Only thing different is the MS is calling the shots instead of the ICM...but the numbers are the same.

Also known is that isn't not just my MS. I just built another MS2 flashed it with my settings to see if it was my unit...it is not. The new one did the same thing.

Ok that being said. I did try MSD coil packs....and MSD wires. They didn't help at all. I think the stock ignition puts out around 115-120 mJ...and the MSD/accel coil packs are at the same rating. That should be plenty of juice..Heck I have been zapped with my have being 2-3 inches away from the towers before.

This problem happens at all boost levels, but gets worse as the load increases. It never did this when the PCM was making the signal...only the with the MS.

Lance. WHen I had the input capture set up as suggested, The offset was +70deg. After reading the megamanaul, I saw that the number should be input as -70deg as the sync comes 70deg after top dead center. Maybe its just a mess up in the MT/trigger wizard code...IDK. But there is a confligreation there between what it says, and what My screen displays and what the timing light reads. I'm not saying what the light reads and the screen display are different. I can get them the same. But it shoudl be a negative 70degrees, not positve...as that would denote 70BTDC. It would on;y be that if the crank spun couterclock wise, but it doesn't. It spins clockwise. I even looked at a crank. At TDC 1 notch is right on the sesor....60deg later anothe notch, and then 10 deg later, the sync notch.

I figured I would get the the service manual to see what it says thinking I might have overlooked something 10+ monthes ago when I was dong all this. The manual says that at TDC the signal goes high for 120degs, then low for 60. So thinking that the input is ever #1TDC event, I thought " Hey. The U4 flips the siganl, so I should switch it to Falling edge. Maybe that is whats wrong. So I put -70 in the trigger wizard and it ran , but bearly. I managed to get a timing light on the crank pulley before it stalled and saw it advanced alot. WHen I get the numbers in trigger wizard to line up, it is at positve 10deg offset.

I just played with it thinking that the less advace time I have and the more base/offset time I put in might do something...so I tryed it. I advanced the amount of offset advance and turned the table advance down and the problem MOVED!!!. Its not gone, but it changed for the first time in a 10monthes.

I did the saem thing with the offset and falling edge and got the same resluts...advacne the offset, and retard the adv table.

So in conlcusion, something is wrong.

Oh yeah. I even tryed useing a sheilded twsited pair as the EST line. No change took place with that "mod".

AJ... 400 hp has been put to the wheels with no mods to the block itself. Althought oringing the block is not a bad idea. Personaly I use a SCE titan ICS gasket...then o-ring is built into the headgasket instead of being layedin into a groove in the block.

S.Bretz · Post by **S.Bretz** » Thu Sep 28, 2006 11:28 am

Ok here's a DL with the problem

The first inccedent is in 2nd gear. It pulls threw and becomes normal after the problem area. You can see the plateu in the rpm curve starting around 338.9 to 339.1

Second pull 3rd gear, more boost. It won't go past the 67-6800 area.Problem starts around 420.2 andlast until I let off around 422.1

3rd run, 3rd gear, high boost around. The dipin rpm around 456.8 was from break boosting to get the boost up. problem starts around458.5 and goes until I let out around 459.3

bluetrepidation · Post by **bluetrepidation** » Thu Sep 28, 2006 4:33 pm

Something is DEFINITELY wrong with the way the MS and Saturn ICM interface. This must be it. Some signal is just off a bit. But that is good news that you got the problem to shift. We REALLY need to scope these leads. I'll borrow a digital oscilloscope from work when I get time and post some for us to ponder over.

A.J.