MSefi.com read only forum (Jan.15,2018)

Hello everyone,
after a lot of help and troubleshooting i finally got my car to start. I can barely get the car to run long enough to try and diagnose whether anything is wrong with the ignition, or if its just how far off my VE table is so...

The problem i am having is that it has a very unstable idle, if i look at the timing through the timing light it is at least 5 deg off from the timing wizard (should be seeing 15deg, but cant get it to idle happily below 20deg)...it also seems to jump as much as +/-10deg(although it may just be the uneven idle/change in rpm?). There seems to be a lot of conflicting information about what output and dwell to be running with an MSD box, i was curious what people have done, or if the proper ones could be explained to me:

Unilite distributor (acts as points, wired up per MS diagram-link at bottom, with no C12, C30 capacitors. could this affect the stability?) connected to pin 24
Mallory Hyfire 6AL connected to pin 36

Input = rising edge
crank trigger = trigger rise
coil charge = standard
spark output = going LOW
max dwell = 25.5 (had as low as 3.5, didnt notice a difference)
max spark dur = 25.5 (had as low as 1, didnt notice a difference)

I have the distributor locked out, and im starting out with just the base VE and spark tables.
http://www.msextra.com/doc/ms1extra/Diz ... ite_v3.htm

Thanks for the help.

Anyone have an idea about the dwell settings at least?

They want you to post this at the MSExtra.com forums, as they refuse to even help troubleshoot. I got my answer in the MSExtra forums in about 40 minutes.

Thanks for the reply. I understand that must be the case since my posts keep getting moved...since im running MSII and have an ignition troubleshooting/tuning question about it i can see why i should be posting at MSextra.com instead of the forum titled EXACTLY what my issue is in ("MS-II Ignition Setup, Tuning, and Troubleshooting") sorry if im coming off harsh, im just getting a lot of conflicting information about literally everything, including where to post questions about the conflicting information.

I'm not sure which code you are running, and your posts have probably confused the moderators on that point as well as you seem to be referencing MS/Extra documentation but using B&G code settings. If you are running MS2/Extra code, you will need to post the questions at MSExtra.com. If you are running B&G code, you should post the questions here. The thing is, the two directions for how to run MSD are different depending on the code, and mixing settings and hardware from different directions can get you in trouble as they often have different ways of handling things. For example, B&G code has you set the dwell and spark duration to 25.5 ms to get a 50% duty cycle output signal. With MS2/Extra, you would instead set the spark output mode to 50% fixed duty cycle. The settings are different enough that they have the split forums to avoid confusion.

Thanks for the clarification, I was aware of the different codes, but not of their differences programatically. I am running MS II rev 2.90500.

As i had stated i had set the dwell and max spark to 25.5 but had also brought it down to 3.5ms and saw little difference between the two (granted i was only at ~1000rpm). These settings are now at 25.5 as they should be. What is the correct base ignition settings for B&G code then: rising edge(inoput), trigger rise(crank trigger), standard coil charge, going low(output)? Im getting really confused by the posts on the MSefi website about the different settings (once again about dwell and going high/low for outputs):
http://msefi.com/viewtopic.php?f=89&t=30652

I had previously asked about the wiring for a unilite and you had helped me out Matt, but as i had said i did not install the capacitors c12 and c30, that would be the only hardware issue that i would think could cause the timing fluctuation i was seeing at the crank ( i dont know the purpose of c12/c30 so my guess isnt an educated one, but all other wiring was done by the book). ..both of these times i had linked to the article from MS extra site, i couldnt find a better discription than there for the MS to unilite wiring, i assume this wiring doesnt change between codes.


Thanks for the clearing up

dustbull70 wrote:What is the correct base ignition settings for B&G code then: rising edge(inoput),

This is dependent on the distributor pickup type.

trigger rise(crank trigger), standard coil charge,

Correct.

going low(output)?

We've usually had better results with going high.

Thanks again Matt!

Im running a unilite distributor, since its running o.k. im not too worried about the input signal...i had also read about the going high vs going low output, that was the reason i started this thread. Ill try everything out this weekend and hopefully get it tuned well enough to idle and maybe drive..

...OK, now im not even getting a spark,im getting a cranking trigger from the distributor, but no output...I dont know if i fried the board or if its something stupid. Putting a multimeter to the + and - wires going to the coil: with the key on i get 12V, but while cranking voltage is going down approaching zero??

Any help would be amazing. it seems like once i figure one thing out something else goes wrong..

Well, i didnt fry the coil, but i havnt tested the Hyfire 6AL box yet-ive been bypassing it to try to get the engine going. What im confused about is what changed from last week to this week? Wiring is all the same, i dont know what could cause there to be no spark now...Im thinking that maybe the battery voltage had dropped such that with the starter cranking there wasnt sufficient voltage to power the Myfire...any thoughts as to what happened? ive got 5 days to come up with something before im back home.

If you aren't running the Hyfire and aren't getting 12 volts to coil positive, check your wiring.

Thanks for the reply, i did a few test and have come to the conclusion that my timing was off, BUT the TIMING LIGHT is causing noise in the signal... with the trigger pulled on the light the tachometer jumps up to 2000rpm when cranking...with the light off it seems to be giving true rpm readings, but i cannot attest to the spark (with the plug wires off, no timing light i had sparks arcing from the dist cap up 3" to the grounded windshield wiper motor-id say it can send a spark when it gets a good signal).

SO i think this is proof as to why you need to install the c12 and c30 capacitors on the board...I got lucky w/ my timing the first time i tried starting the car and i didnt have to timing light hooked up. As soon as the timing light came into play ive had spurradic readings/no starts...if the c12/c30 isnt the solution im completely out of ideas as to what can be wrong, ill know before noon tomorrow.

i installed c12, c30 and made sure that the input signal wire to the MS was completely shielded and i am still getting very weird signals ONLY when i have the timing light on. otherwise the tach and tunerstudios rpm gauge are very steady. I can get the engine to caugh over but that is all, nothing more...

I am also a very low cranking voltage (8.3v) the mallory hyfire needs 8 to operate...how much can the MS work off of, is that sufficient enough to send signals to the injectors?? So i know im getting spark since it caughs for a few revolutions before dying...What should i be looking at??? i am beyond confused, and yes the battery is good, just loses voltage from all the cranking

Got a new battery and am getting over 10v at cranking...im getting a spark, but i seems to have a 'roving' timing advance that doesnt want to stay near what it is set to (im using a different battery to power the timing light, so it isnt influencing the signal as previously stated)...thats one of the reasons why i can get the engine to run 1-2 revolutions at random points of cranking. any ideas of how the timing is wandering like this? my wiring is identical to the MS extra link on my first post for the pullup circuit, and internal wiring, the cranking rpm is constant in tunerstudios so i dont think its the unilite/input signal, but i dont know what to look at from the output that would be causing these timing variations

Are you using a 'clever' timing light? I have a Krypton one which allows you to dial in advance - and that doesn't work with the EDIS setup on my car, doesn't even flash let alone at the right point. My much older basic one which needs a direct connection the the plug, does, however.

The light is approx 15yrs old, very basic light..there is a clip that goes over the spark plug wire, not a direct plug in...I had the exact same ignition system in the car for two years and had no problems whatsoever, the only thing that ive modified was the pull-up circuit and basically splicing the MS in between the dist and the hyfire.

One source of noise that i have not thought of until now: there is one hole in the firewall (~3/4") that all of the engine related wires go through (minus the signal input for the MS, that shielded wire goes through another hole). Could the Hyfire orange/black wires close proximity to the INJ1/INJ2 wires be influencing their signal going to the coil??? Thanks for the help and ideas!

anyone have any ideas? I only get to work on it on the weekends, i need some backup ideas...any setting issues or anything to look at other then those wires. thanks

Please post a data log of the unstable idle and a copy of your MSQ.

I dont have a recent data log of the issue...the only data log i have was taken on the weekend that it actually ran for several minutes. This is the current msq that i am running...i dont have a restore point back to what it was when it was running, but i see nothing that is wrong/different then that setup. Hope this helps, im going crazy not being able to drive my car (a month past the expected date!)

All I can see from that data log is that the cranking settings need some adjusting.