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-   -   Lost sync 11 adventures ms3x (https://www.rx7club.com/megasquirt-forum-153/lost-sync-11-adventures-ms3x-1145196/)

Monika 06-15-20 01:21 PM

Lost sync 11 adventures ms3x
 
Hey i'm having issues with lost sync 11 on my fc3s.
New motor build and first time using megasquirt. I follow all the info on diy and aaron cake. Pots all the way ccw, install the board jumpers, make sure all the grounds are in good shape. A good buddy of mine with basically the same setup loads his tune. Fires up first crank with no issues. Great!. Idles fine, revs smoothly but the lost sync counter keeps going round and round with reason 11. I starting doing all the research of everyone before me who has had this issue....check and recheck grounds, cas wiring and try to minimize any sources of noise. I do find a few small things but no big deal. Still no change. lost snyc 11. I then"tighened up the cas air gap in small amounts until about .004. As the gap is getting tighter the sync counter is going around faster and faster and running more rough. ok....throw in another cas and do the same. Still runs rough with lost sync. So i take out the cas and make an adapter with a socket and drill and spin it up to about 3500 rpm while jiggling various connectors etc...... I found that one part of the harness when i moved it the lost sync would slow down!.....the more of the cas harness i moved from other parts of the car the better it go.Yay i found the issue! Install the cas and totally re run the cas harness out of the way from any other wire up to the db37. Fire it up same issue. Re check grounds, all is good. I then remember reading that aaron gaps the cas to " about the thickness of a business card" so i start increasing the cas gap. Well at about .020 the lost sync starts going away with the engine running! So i gapped the points to .030......now we are getting some where. I'm getting a few lost sync 11 above 5500 rpm.

What would my next step be?.....Try resistors in series with the VR pick ups?

Can i use the tooth logger to check and adjust the pots to help correct this ?( Ive tried to do some logging but i dont understand what i am looking at.)

elturbonitroso 06-16-20 04:33 AM

did you change the cam input wire for a shield one the wire they use for the ms3x card its more for a hall effect sensor and not a vr sensors also ground the ecu straight to the battery.

Monika 06-16-20 06:21 AM


Originally Posted by elturbonitroso (Post 12418749)
did you change the cam input wire for a shield one the wire they use for the ms3x card its more for a hall effect sensor and not a vr sensors also ground the ecu straight to the battery.

Good idea. I'll run a shield for the cam input. I have ecu grounds to the engine right now. I'll try direct to the battery. Thanks :)

elturbonitroso 06-16-20 11:16 AM

on vr sensors always use shield wire and only ground one end

Monika 06-27-20 03:06 PM

So update: Tried all many different values of resistors with the cas wiring and made some more improvements to the power and ground system. Still was getting a couple sync losses at high rpm just reving in neutral.I caved and bought the FFE hall kit. I installed everything per the ms3 manual. Did the board adjustments on pg75. The only thing i am having an issue with is where to set tooth number 1 in ref to TDC. I have the racing beat dual pulley and the wheel can go on many ways. None of which seem to line with tooth #1 at TDC or at the hall sensor for both methods listed in the ms3 manual. Am i hooped with this pulley? Any info? Thanks!

elturbonitroso 06-29-20 04:36 AM

put the engine at TDC and take a picture and post it.

Monika 10-16-20 10:55 AM

Update...car is running great. Just incase anybody else has this issue....it does not matter how the ffe hall wheel is clocked. All you have to do is adjust the tooth offset angle and ballpark it....each tooth is 10 degrees. Lock the timing with plugs out (so it spins faster and more constant) and have a buddy crank it and check the timing. Continue to adjust the tooth offset until you are at you desired timing mark. Then fire the engine and fine tune the offset.


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