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Ms3pro sync error - Missing tooth at wrong time with FFE hall - ms3pro
I've been dealing with a major sync error at WOT for the last year or so. on my old turbo it was not a huge problem as I was not running enough boost to do any major damage, but it wasnt constantly doing it back then either. I've been slowly eliminating variables.. I think. I had a ground near the Ecu panel that everything was grounded to. My smartwire PDM was also grounded to it but I was having intermittent blown "fuse" issues having the smartwire grounded there so I decided to run EVERY ground to the battery. This eliminated my smartwire going on the fritz at random times. Didn't help anything with the sync errors on the megasquirts side however. Then I thought maybe it was was the water injection blowing out the spark on my stock 9 heat range plugs (considering the massive gap they have), so I switched to iridium r7420-10's and went to see if the much better plugs helped the issue.. as the only way i have to test is to go WOT, It resulted in a cracked front iron, sync loss reason 2 missing tooth not when expected (or something to that effect). Obviously the issue is not fixed. Not a big deal as i have spares of everything imaginable but what concerns me is not knowing why this is happening as it is not the first time but the first time it resulted in engine damage. Needless to say i can't afford to rebuild an engine just to risk it every time I tweak a variable.
What I know: I get no sync errors at lesser loads. I can run the engine through the powerband at any given time at lighter loads without hiccup, so this is a high load issue only. My ignition setup is stout. reading my sig you can see that im using smart coils in direct fire paired with 7420 iridium plugs at roughly 5ms dwell at 4.5k rpm
I'm using the ms3pros harness and the shielded wire CKP+ as this is what the manual says to use with a hall sensor.
hall sensors ground ran to the dedicated sensor ground in the harness.
power is 12v and the sensor does not need a pullup or anything according to FFE. it's also the same sensor diyautotune sells.. I actually replaced this sensor with the DIY unit as another possible attempt to fix this issue.
sensor gap is at whatever FFE has it set at which looks about the thickness of a credit card.
I don't see any hubcentric runout and the wheels is centered right on the sensor
the error appears to always happen at WOT within a couple hundred rpm of 5000 rpm. the datalog (which I will attach with my tune. when i get home) shows sync loss at exactly 5000 rpm in the event that cracked the front iron.
the shielded wire is not near the coils but does run under the alternator if this is relevant. not sure how noisy an alternator is?
Possible causes that I can think of due to unconventional setup:
As far as i know the r7420-10's are resistor plugs and so were stock 9's I had in prior. I do not have resistor wires as im using an experimental direct coil on plug setup with boots that house a spring. I have not put a resistor in these boots as i do not want to reduce the spark energy. but maybe this is the issue? Are resistor plugs enough without resistance wires?
I have the smartwire power distribution module providing power to the terminal strip that feeds 12v+ to the coils/injectors, idle control valve, hall sensor.. Everything except the power to the megasquirt power wire as Smartwire's instructions said not to feed the computer power through the PDM and to only use the PDM as a switching unit for the ECUs power relay. Could the hall sensor benefit from its own power source too? could it benefit from a power ground instead of the sensor ground?
lastly is there a way to test to see if issues persists without destroying engines every time?
Trying to think of more things. I bought the turnkey preassembled ms3pro and the FFE hall setup specifically to avoid all this notorious megasquirt noise stuff.
ill post the msq and datalog later today in hopes someone can see something i cannot.
I had a high-RPM/load misfire that cracked both front and rear irons when I was on MS2. I believe this was from having the spark plug wires zip tied together and getting a crossfire that fired 60* advanced.
Gleaseman had the same issue multiple times and I believe he had the same conclusion, also on MS2 I believe.
Are your plug wires touching at any point?
On MS3X with the FFE VR kit, I had intermittent sync loss at first startup. I believe I switched from rising edge to falling edge (or the other way around) and it went away completely. I’ve seen other setups that also preferred one and not the other, just make sure to re-zero your timing or you’ll be off by the width of one tooth.
I have not tried to change the edge, I just set it as falling edge as that's what FFE's manual said to use.. good idea. I do not have plug wires at all. direct coil on plug.
FWIW, I used NGK BR10EG plugs with really good success. They're 10 heat range, have a gappable ground strap, and the same resistance as r7420-10's. AND they're $4/each
I would like to update where I am on this. I'm not sure, but I think my issue lies with the terminal strips that I used from Aaron cakes megasquirt install. The strips are rated for 15 amps TOTAL.. not at each terminal like I initially thought. They have tini sheet metal bridges that transfer current from terminal to terminal which look not much thicker than a piece of doubled over foil. The smart coils are rated at 19 amps each and although there is only one firing at a time, at 5000 rpm at a high dwell there would be a constant draw. Because of this, got to thinking and I think I have a voltage drop through the strip because the demand of the coils plus 4 injectors and BAC are probably drawing energy away from the hall sensor when the hall sensor needs it most. if this is true I am unable to register this drop in the data logs because the megasquirt has its own power supply. The first thing I did was eliminate the 15amp strips and instead used robust bus bars, then I took and rerouted power to the hall sensor from the same power source the ECU uses so they see exactly the same voltage (and probably far less noise). It's getting warmer out, I built another engine and I'm near the point of taking it on the road to test this theory.
Well, it's spring and I finally had a few warm enough days to test out my new wiring setup.. A few dozen WOT pulls and zero sync losses makes me a happy man.
As I said in my prior post, giving the ecu and hall sensor their own power source and upgrading the lightweight terminal strips that feed everything else with robust bus bars.. seems to have done the trick. Most threads jump straight to grounding issues.. from my experience the +12v feed is just as critical. While I was at it, I fed the new bus bar with an additional redundancy feed in the case that one of the relays goes out there's still power. This is likened to how aviation systems are set up.
My observations: My IGN-1a coils have no issue lighting the pre-turbo water mist (spark blow out was one of the things I was suspecting the issue to be). Audibly the engine sounds much happier and less angry when under high load. I suspect I was getting timing retard at higher loads and/or weak spark prior to this. As wider tires are something that changed along with the new wiring setup, I'm not sure if my used 285/30/18s are too hard due to heat cycling (they feel hard for a 160 treadwear), but I'm having traction issues in 3rd now. I plan to buy the same tire here in a week or two to determine whether the engine is just making that much more power or the tires I have are ****. I hope they're ****.. My laptop no longer goes offline at high load when running tuner studio.. as the ECU has always been on its own power source, I'm not sure what fixed this, but i'll gladly take it.
I am having the exact same pattern as the OP.
My setup : 13b-REW freshly rebuilt, MS3x V3.0 (hand built), GT35, 4x IGN-1A, on E85.$, FFE VR trigger kit.
This is a full on drift car so it is stripped. Engine harness is brand new, made by me. No solder at all, only quality crimping, MS is grounded at engine (both MS and X daughter board).
It is not my first MS install so i was particularly careful about power supplies, grounds and sensor grounds.
Power supply comes through relays for everything, except for ECU and AEM lambda controler.
Engine is being run in on the dyno so rev limit is at 6500rpm. This is not my first rotary tuning.
I am experiencing sync losses only on boost and at WOT. Boost controler is doing nothing at this point, we are on the WG spring.
As long as TPS is kept around 50%, no sync loss at all.
I just ordered a Hall sensor from FFE, because i couldn't be bothered to play with the pots again, as i lost a full day on another FD for the same problem.
Well, that was before stumbling on this thread.....
I have my spark plug wires touching eachother so i will try separating them.
Also, my ignition setting was on Rising edge instead of Falling as per FFE instructions. Will try changing that also (and put the timing light back on of course).
If i could avoid going through the hassle of opening my brand new and sheathed engine harness, to pull a +5V for the Hall sensor, that would be great.
I'll report back after tests.
To the OP : did you finally understand what solved your problem ?
ok guys 12v and ground straigth to the battery that would solve a lot of problems.i never have sync problems and i install a lot of ms in different cars.
ok guys 12v and ground straigth to the battery that would solve a lot of problems.i never have sync problems and i install a lot of ms in different cars.
10-29-18, 03:30 PM
