ms3-pro starts perfect sometimes other times no start.

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E30_Driv3r
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ms3-pro starts perfect sometimes other times no start.

Post by E30_Driv3r »

BMW m52b30 engine in a bmw, new built motor with maybe 200km on it max. ms3-pro, 60-2 wheel and MAF for primary fuel load.

I was previously running ms3-pro on the same engine without this problem. What is happening is that it will catch and and just die 5-6 times in a row and randomly if i start it and give it some gas it will fire up no problem. Could this be fuelling related? Trigger related? Me thinking it had to do with the trigger I ran the tooth logger - log looks great. The only thing I can say that might be iffy is that I'm triggering on the falling edge - but that has never been a problem. I strobed the motor and timing was dead on when i set the fixed timing to 0deg and it did not move. I want to say I'm good there. Only other changes with the new motor is I had installed a billet fuel rail and an higher amperage alternator. Other than that everything is the same. i've attached a log, msq and trigger log. i would realllllly like to take care of this since ever time it fails to start it pops/backfires from the exhaust loudly...not exactly neighborhood friendly. Noise filtering maybe needed?

thanks!

https://www.dropbox.com/s/zjpzda0b3p04d ... 0.msl?dl=0 Log of me trying to start it over and over and it finally starting

https://www.dropbox.com/s/jc4xm49lxf1kr ... 5.csv?dl=0 - trigger log of me trying to start and it finally catching
grom_e30
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Re: ms3-pro starts perfect sometimes other times no start.

Post by grom_e30 »

weird thing in the datalog you get status1 = 136 every time the engine dies that's full sync so would be full sequential if you were running that way. but at the end where it starts status1 = 8 so only half synced.so semi sequential and wasted spark.
1990 bmw 320i daily driver with m20b25 ms3 sequential fuel, 380cc injectors, d585 coil near plug, home made cam sync, launch control, fan control, vss, homebrew egt logging what's next????
E30_Driv3r
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Re: ms3-pro starts perfect sometimes other times no start.

Post by E30_Driv3r »

grom_e30 wrote:weird thing in the datalog you get status1 = 136 every time the engine dies that's full sync so would be full sequential if you were running that way. but at the end where it starts status1 = 8 so only half synced.so semi sequential and wasted spark.

strange. I have it set to run as full sequential. I noticed in TS it wouldn't say fully synced at the bottom - wonder if that has anything to do with it.

So, ive backtracked and looked at my cam sensor setup/config. I may have it wrongly setup. It uses a cam trigger like this:

Image

Would this fall under a half-moon type? I'm thinking yes....

So, with that said the second active trigger setting is wrong if that's the case since I had set it to falling edge. Reading the MS docs for half-moon style triggers TS you must set the trigger to Poll Level and find out if it uses the HIGH or LOW setting.

I'm going out to the garage to confirm/set this up and report back, hopefully it cures my issues!
Last edited by E30_Driv3r on Mon Sep 29, 2014 12:47 pm, edited 1 time in total.
grom_e30
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Re: ms3-pro starts perfect sometimes other times no start.

Post by grom_e30 »

if the ecu only has half sync eg does not get the cam signal it will run but in wasted spark and semi sequential fuel and will switch over to sequential when it gets the cam sync. every time it catches and dies its running full sync (sequential) the last bit where it starts it does not get the cam signal and runs on semi sequential happily.
1990 bmw 320i daily driver with m20b25 ms3 sequential fuel, 380cc injectors, d585 coil near plug, home made cam sync, launch control, fan control, vss, homebrew egt logging what's next????
E30_Driv3r
Experienced MS/Extra'er
Posts: 193
Joined: Sun Dec 14, 2008 5:31 pm

Re: ms3-pro starts perfect sometimes other times no start.

Post by E30_Driv3r »

grom_e30 wrote:if the ecu only has half sync eg does not get the cam signal it will run but in wasted spark and semi sequential fuel and will switch over to sequential when it gets the cam sync. every time it catches and dies its running full sync (sequential) the last bit where it starts it does not get the cam signal and runs on semi sequential happily.
gotcha, like i'm thinking as well it may be a improperly setup cam input. see my post above I will update in a bit!
grom_e30
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Re: ms3-pro starts perfect sometimes other times no start.

Post by grom_e30 »

does the m52 not use a pole level 50/50 or half moon type trigger?????


edit just saw the photo, i guess it could be syncing wrong and phasing the spark sometimes so its the wrong stroke.
1990 bmw 320i daily driver with m20b25 ms3 sequential fuel, 380cc injectors, d585 coil near plug, home made cam sync, launch control, fan control, vss, homebrew egt logging what's next????
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Re: ms3-pro starts perfect sometimes other times no start.

Post by jsmcortina »

It does sound like you are syching to the wrong phase.

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E30_Driv3r
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Re: ms3-pro starts perfect sometimes other times no start.

Post by E30_Driv3r »

It was the cam sync. Switched to Poll/High phase and no more backfire starts :yeah!:

I have the "check tooth" at #0, going to try tooth #1 to see if there's a difference
E30_Driv3r
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Re: ms3-pro starts perfect sometimes other times no start.

Post by E30_Driv3r »

Ok, so i'm revisitng this. Since the change to poll level car fires up every time but I've noticed I trigger the "Cam fault" aka 13# flash code and going through some old logs the car is only running @ Status1:8.0 which would indicate Half-sync... I did a composite log and I do get a cam signal, but it looks very unstable. I will include Composite Log, MSQ. For the composite log start from 83 of 100.

Any suggestions? Should I play with the "check tooth #"? A friend of mine with ms3x running the same motor as well has a different setting (falling edge) for cam and he gets full sync. I tried that and my car doesn't start. Strange...

https://drive.google.com/file/d/0B3GWeG ... sp=sharing

composite log link
E30_Driv3r
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Joined: Sun Dec 14, 2008 5:31 pm

Re: ms3-pro starts perfect sometimes other times no start.

Post by E30_Driv3r »

More playing around. It seems at idle I cannot produce a steady cam signal but at part throttle ~1500rpm I get a decent steady signal most of the time, Still not enough however to satisfy the MS3-pro to be full-sync. perhaps this sensor is no good/on its way out?

here's a composite log at idle holding the rpms up to 1500ishRPM.

https://drive.google.com/file/d/0B3GWeG ... sp=sharing
E30_Driv3r
Experienced MS/Extra'er
Posts: 193
Joined: Sun Dec 14, 2008 5:31 pm

Re: ms3-pro starts perfect sometimes other times no start.

Post by E30_Driv3r »

Fixed! Turns out after some testing my hall sensor needed the 1K pull-up resistor. Fault is gone, Fully synced now. Composite logs look perfect!
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