Hey guys!

I'm stuck with tuning of my MS 1 v3.0 on spark advance.

Symptoms are as follows:
* on the stock ECU everything is working fine. I am able to tune the spark by the strob light and both marks are aligned as they should be

* My seetings in MS are attached

when i switch to MS, the marks are waaaay off and i just can't align the marks by moving the CAS in any direction. Even worse the closer to the marks i get the worse engine is working.

The engine working at it's best when i add by 'Trigger Angle Addition' 22.5 deg. But again marks are way off.

Trying to tune the spark advance table while running the engine in the 2-3K RPMs seems to have almost no effect. I tried setting as extreme as -20 to +20deg with close to none effect.

Around 3K RPMs i have a really bad engine behaviour. It sounds like pinging (yes i'm n/a luckily), but above 4-4,5K it sounds feels much better. I just can't get rid of this pinging with almost ANY variation of VE or spark advance

I tried to play with different settings all with negative results. I'm starting to think that i have some problem in the MS circuit, is there a proper way of checking it?

Again on the stock ECU everything is fine.

All inputs are greatly wellcome!

 

VR sensor wires reversed?

 

I agree with Aaron Cake.

With the stock CAS stab, settings should be 11,1,5,7 with an angle of 65. If that doesn't get it for you, and you have to move the CAS all over the place, the wires are probably backwards for your primary trigger.

Ken

 

Thanks guys!

I really appreciate your help!

Will travel to the shop which installed the MS for me to double check everything.

I've had some thoughts that there's something wrong with VR sensors. Even oredered additional LM1815 circuit for testing...

 

Hey everyone!

Been a long time!

Had not much free time lately, but i've unfreezed my RX-7 MegaSquirt project.

Still have troubles seting TDC with a strobe light, although we've changed both LM1815 circuits and made an extra board to avoid noise interference.

Symptoms are as follows:
* in MegaTune i see the correct RPMs and with strobe light connected to trailing it is also correct, but when i checked leading it showed current RPM*4, when it should be multiplied by 2, because of the wasted spark. I suspect this is the reason why i can't set spark properly.
* when i align timing by the first mark (wheel decoder 11,1,5,7 with an angle of 65) car just can't idle and if i try to move CAS in advance direction it gets better and better and becomes stable at around 45(!!!) deg from 5 deg mark.
* when i try to find stable idle by MegaTune i found that trigger angle of around 35 works best, when normally it should be 65.
* stock ECU works just fine when aligned to 5 deg mark.

So i came to conclusion that something is wrong with my leading coil wiring from MS, maybe you have a clue of what could be wrong more specifically?

Thanks in advance!

 

Actually, it sounds like either you have the ignition output the wrong polarity, or the VR input the wrong polarity.

Have you tried switching the wires like Aaron Cake said?

Ken

 

I've tried swapping wires from CAS to second VR sensor, but the car didn't start at all in that position. Also the who installed MS for me assured me that they tripled checked the polarity there...

So it is possible that just output wires to coils needs to be switched?

 

When setting timing you need to change fixed angle to -5. Then change it back to -10 when you have set correctly. You might already know this but I thouhgt I would mention it.

 

This is actually only correct with Trigger Angle set to 60, and if you have set it to 65, you should set timing at actual 0.

 

No, that's not true, when checking timing, you should always set fixed angle to -5.

It really sounds to me like your primary trigger VR polarity is backwards.

Ken

 

Yeah, you're right... I forgot that the marks on pully are 5 and 20 ATDC...

So, shall i just switch the wires going to primary VR?

 

Yeah, give that a shot. On ms2 you could just switch the edge it triggers on, but ms1 doesn't have that ability.

Ken

 

Are there a lot of mods need to be done to upgrade to MS2?

 

After switching wires on primary VR RPMs got to where they suppose to be - twice the actual value on the leading. So one problem seems to be solved.

BUT, at the Trigger Angle that i should be able to set 0 by the mark with a timing light ((wheel decoder 11,1,5,7, Trigger Angle 60, Fixed Angle -5) i still can't see no marks at all, no matter what direction i turn the CAS. And the idle is shitty.

If i set the Fixed Angle to 40 (to get 45 deg more advance) i have a close to perfect idle, but still can't see marks (they're somewhere below the water pump).

I took pics with CAS cap off and a timing light with each setting, so it is possible to see the wheel position in each situation. Any comments would be welcome!

 

you are probably a few teeth out still

 

Yeah, I figured that out, but how do I set up 0 mark?

 

Not a huge number. The main mod is to change where the 2nd trigger VR input is wired.

Ken

 

Yeah, the CAS could be stabbed wrong, or you might want to try the other leading spark wire (I know, they're wasted spark, but in my experience with some wires and lights it matters).

Ken

 

The CAS is stabbed correctly 100%, as with stock ECU marks are on the target... Will try to use the other leading wire, thanks for the clue