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

So I figured out atleast part of my high idle problem. As it turns out the distributor got loose.

Question 1) Can anyone tell me how to configure MSII v3.0 to not adjust advance so that way I set my distributor back to TDC on the #1 cylinder with a 4.3 TBI, HEI, 8-pin module?

Question 2) Can anyone recommend parameters for the trigger offset and spark table as I am back to square one.

Thanks
Will

Can't you just unplug the HEI bypass connector so that MS doesn't control the timing?

Ken

Thanks Ken,

This is probably a stupid question but: How do I know which is the bypass connector?

I have read all about the bypass wire on stock situations but I have never had that situation and I made all the connections to the distributor as per the megamanual 8 pin module.

Will

Hello,

I am a first time tuner and have read through the various manuals a few times. I have the basic steps but I am getting to a points where I can't make the next step.

4.3 TBI, MSII, V3.0

Question 1: Once idling (around 1500rpms) would it be best to tune the spark table first to try and get the rpms down to a normal range? Or should something else be adjusted first?

Question 2: Since I used the table generator, what is the best way to approach the spark table? (should you change the advance, rpms, or map columns)

Thanks so much for helping the newb

Will

ironwill11 wrote:Question 1: Once idling (around 1500rpms) would it be best to tune the spark table first to try and get the rpms down to a normal range? Or should something else be adjusted first?

Just my way of doing things, of course.....but I prefer to adjust timing for best idle, then adjust idle rpm using IAC/throttle stop screw (whichever you're using).

Ken

Hello,

Anyone have any suggestions for setting TDC on my 4.3 TBI, MSII, v3.0

I read from several sources online that at idle factory ECM is looking to keep the advance at 20 degrees. My MS II is currently at 20 advance (read out in tunerstudio and confirmed with a timing light that has an advance knob). I figured this should be pretty close since at idle it wants to be around 20 degrees (provided MSII does the same thing).

I unplugged the bypass connector but the engine wont start and run long enough for me to check to see if the number 1 cylinder is at TDC.

When it is cranking it sounds like the engine is running (and going faster then the starter) but it doesn't catch.

Question 1: Is it reasonable logic to think that I am at TDC based off of the advance MSII is giving me?

Question 2: Should I be able to start and idle the engine when #1 is at TDC?

Question 3: Can anyone explain what MSII is trying to do with the advance and what variables it is using to do it?

Thanks for all help.

Will

Most engines will start best with a bit of advance. Say 5-10 degrees.

Bypass is pin "B".

Hello,

4.3 tbi, msII, v3.0

So I confirmed and re-confirmed my engine is has a base ignition timing of 0 degrees at TDC on the #1 cylinder.
I still have an idle of about 1500rpm.
According to my spark table based off of the map reading and advance, the rpm is right wear it should be. I have about 20 degrees advance at idle. It seems like the table wants about 15 degrees to idle around 900. Research online suggests 20 degrees is what gm does.

Question: Can anyone point me in the right direction on how to create a spark table accurately? Or should i just adjust the idle screw?

Thanks for helping the newbie

Will

Can anyone point me in a direction for useful information the beginning of making a spark table?

Will

Hello,

4.3 TBI, MSII, v3.0

Am I missing something here?

I am at 0 degrees top dead center like 4.3 tbi is supposed to be without computer advancement. I can't get the idle to come down from 1500rpm. I have moved the trigger offset up to 25.0 and that brings the rpm down to 1100. I move the rpm around on the spark advance table and get it down to about 1050 but the megasquirt adjusts starts lowering the advance and the idle goes back to 1100.

What is MSII doing with the advance? What am I missing?

Will

Please make sure your timing is correct, then post a data log of the idle issues and a copy of your MSQ.