Timing won't change

[Nismo280zEd]

Ok so i discovered a big problem today. My timing does not change as i change my trigger number. when it was at 90 and i moved it to 60 it moved about 10 deg then after that 20,40,50 it stayed in the exact same spot. So i inverted my dizzy pickup wires, it put the timing spot on at 15 but once again changed the trigger angle, nothing changed.

 

I'm really irritated and mad and about to scrap the project so i'm walking way and going home.

 

If you guys can think of some things for me to check this weekend let me know.

-Ed

[naviathan]

How is your ignition setup?

[mobythevan]

I am not sure where you are in the setup procedure so I'll just lay it out again and you can tell us where you are.

 

1. first, set fixed timing to 15

 

2. next put timing light on engine and crank engine with fuel injectors unplugged so it doesn't fire

 

3. adjust trigger angle until you see 15 on the crank

 

4. If you have to adjust trigger angle to less than 50 or more than 70, then recheck your distributor phasing. Loosen the hold down and turn the dizzy a little to get the trigger in a spot that will keep you between 50 and 70. I assume this is a turbo engine with 82-83 style turbo dizzy, if not let us know your setup again as this step may be different.

 

OR, do it this way:

 

1. set fixed timing to 15

2. set trigger angle to 60

3. have someone crank while you hold timing light

4. loosen distributor and slowly turn either way to get 15 on the crank

 

Remember to enter -10 back into fixed timing to allow MSnS to use the spark table when you are finished.

[Nismo280zEd]

This is really bothering me and I don't think I'll be able to sleep tonight. I'm going to grabe my oscilliscope and hook it up to my dizzy and see what kind of signal I'm getting from my VR sensor.

 

Quick review.. MS1 pcb3.0 with 024s9 MSnSE code. with HEI 8pin ignition module (cause i thought it would be quick and easy to get it running that way HAHA!) I was in the process of trying to "phase in" i guess you would call it my dizzy. I was using a remote trigger to crank my car over and holding a timing light so i could easily watch the mark. This is when i made my discovery.

 

I just read something though... your comment on the fixed timing at 15.. mine was still at -10 so it was reading the table which i had filled with 0's to try and find out what was throwing my timing. When I go back over I'll try this again. So much presure and stress to get this car running... what a day.

[Nismo280zEd]

update... tried what you said... fixed timing at 15... put my trigger angle at70 crank... 15 on the crank. change it to 90 try again... 15 on the crank, change it to 50 try again... 15 on the crank. I change my wires from my dizzy and flip flop them to the HEI module. try again... -20 at the crank no matter what trigger angle i set. of course moving the dizzy changes the timing, but i can't change it using MS.

 

I put a scope on my dizzy... i get really weak waves at about 50mV and it's so sensitive that low that if i just put my thumb on the dizzy I get waves just from my body. I pulled the dizzy out of a maxima... tested it... same thing... 50mV very sensitive but defn' a stronger wave, although two different animals, maxima dizzy is an optical. I believe like the ZX with the wheel inside of it.

 

At anyrate heat index is like 104 still and i'm sweating my ass off outside. I'm very frustrated mad and considering using a different trigger method as this is obviously not working.

-Ed

[z-ya]

If it runs, and the tach display in MT is stable, there is nothing wrong with you VR signal.

 

You say the timing is always -20, you mean 20btc, right?

 

Leave you trigger angle at 70 or so, and in the spark table fill in all the bins around where the engine is idling to 10. Now adjust the trim angle in the spark settings so that you read 10btc on the timing tab with a timing light. Now change the table entries to all 20. You should hear the engine smooth out with more timing. The timing light should show 20btc.

 

If this works, fill in you timing table with approximate advance values for you engine.

[mobythevan]

oh, 8 pin module, do you have it set up correctly? If you do not control the 8 pin module with the correct signals it just outputs limp home mode, which sounds like what is happening to you.

 

Tell me how you have the 8 pin wired, all the pins. Also how is your coil wired into this. This should be easy to sort out, ha ha, famous last words.

[Nismo280zEd]

I'll write down the wiring tonight as i can't remember off the top of my head. However, last night before i left, I did change out the pickup to the one from my 78, gave it a much cleaner signal.

 

Z-Ya... that's the funny part... I was starting and trying to work out idle... now i can't even get her to fire. Just a backfire from all the fuel sitting in the pipe lol.

 

If i can't get this HEI to work, i'm going to go straight to the board and re-wire the PCB for the VR circuit. But I would rather get this working as it's already wired for this. I'm stopping by tonight on my way home from work, I'll write down the wiring and what not.

 

-Ed

[z-ya]

Like I said, if you have a stable tach display in MT, then your VR circuit is working fine. The VR circuit is on the trigger input. It sounds like your problem is on the ignition output circuit somewhere.

[naviathan]

Ahhh, I had this problem. Your plugs are fuel fouled bad enough that they won't fire. Clean them and try again, this time pull the fuses on the injectors until you get the timing straight, that's what I had to do.

[Nismo280zEd]

I'm not sure what your calling a stable tach display since the car doesnt run or start. all I can see is cranking rpm.. and well i wouldn't call that stable as it jumps around while cranking, however I feel confident with the new pickup my VR signal will be MUCH better.

 

I'm gonna make sure the dizzy didn't get 180deg off while messing with it so much. I figured i could use a compression gauge on #1 and crank it by hand until i see compression, then it should be lined up TDC on compression stroke. Trying to avoid taking off the valve cover.

 

At anyrate... here is the wiring for the 8pin HEI

 

 

*******______

*******|HHHH|-Power

*******|HHHH|-IGN (goes to neg on coil)

*******|HHHH|

*******|HHHH|

*******|HHHH|-Ground

*******|HHHH|-IAC-A on the MS loom

VR sig P-|HHHH|-IGN to MS

VR sig N-|HHHH|-IAC-A on MS loom

 

pin 3&4 IAC-A are two different wires going into the MS not the same wire.

[mobythevan]

Could you list the HEI pin names, in particular what you do with pin B. IIRC that is the cranking bypass pin that puts out the fixed timing regardless of the other control lines.

 

 

From my notes

Connect pin R of the 8 pin HEI module to TACH input of relay board.

Connect pin B of the 8 pin HEI module to X12 (S2 connection on relay board)

Connect pin E of the 8 pin HEI module to X11 (S1 connection on relay board)

Connect pin G of the 8 pin HEI module to ground

[trwebb26]

When I had this problem - the actual input in the megasquirt was firing off of the wrong edge of the dizzy signal. I got it pre-wired from RS-Autosport and it came wired incorrectly from them.

[mobythevan]

Thats also a good point. There are two critical things to remember with the 7 or 8 pin HEI modules.

 

You have to do the mod to trigger of the falling edge and you have to deal with the cranking bypass pin correctly. You can search up my TPI install notes to see the mod for the falling edge trigger.

 

If you don't use the bypass pin correctly your timing will appear fixed no matter what you try.

 

If you don't do the falling edge trigger mod your timing will shift around as you raise RPM, seen easily if you enter a fixed angle once the engine is running.

[Nismo280zEd]

Ok, I'll have to take a peak at your notes and then double check my wiring. I just went off of the MSnSE site.