MS cold start help
Discussion
Hi guys, can anyone help with cold starting please? I have MS2 and have problems with cold starting;
when engine cranked with no throttle it fires but wont run
when cranked with throttle it wont fire
Have to constantly 'stab' the throttle in order for it to catch and continue this until it eventually settles down after a couple of minutes.
Bit embarrassing and bloody annoying.
Stepper is disconnected. anyone have some settings I could try or other advice please?
Thanks.
when engine cranked with no throttle it fires but wont run
when cranked with throttle it wont fire
Have to constantly 'stab' the throttle in order for it to catch and continue this until it eventually settles down after a couple of minutes.
Bit embarrassing and bloody annoying.
Stepper is disconnected. anyone have some settings I could try or other advice please?
Thanks.
I'll caveat this response by first saying I'm new to after market ECU's having just moved to a Canems system, so I'm by no means an expert.
But the truth is the basic cold start principles are the same for any petrol internal combustion engine be it carb or injection.
The amount of fuel you administer & air you allow in at cold cranking and during the warm up phase are both critical elements to a successful cold start.
Unfortunately with your stepper motor disconnected you have no real control over the air.
All you really have to work with is the amount of priming pulse fuel, temp corrected cranking fuel & warm up phase fuel you are throwing in.
You say when the engine is cranked with no throttle it fires but wont run.
This sounds like there is enough cranking fuel & no more air is needed, this is also supported by the fact when cranked with throttle it wont fire (too much air).
So just leave the cranking settings as they are, all you need the cranking settings to achieve is for it to fire.
Cranking & running are two very different conditions, which is why the system allows you to configure them separately.
As soon as the engine fires it moves to the temperature corrected running settings (warm up phase), if there is too much or too little fuel/air it will instantly die.
So with the cold cranking working as it should focus your attention on the temperature corrected running settings.
If I had your particular issue, on my Canems system I would be looking to add or remove some air supplied by the Bosch idle valve.
But with your stepper motor disconnected you are making your life much much harder to effect good temperature corrected running settings.
Unless you can reconnect the stepper & get the MS to drive it, you really only have two options, throw more fuel in or take some out on the temperature corrected running settings (warm up phase).
If stabbing the throttle can coax it into life I would look at adding more fuel first and see how you go.
From my limited experience playing with the cold start on my Canems it seems our cars need a lot of fuel to run for the first 20 - 30 seconds of warm up.
Hope some of this helps?
But the truth is the basic cold start principles are the same for any petrol internal combustion engine be it carb or injection.
The amount of fuel you administer & air you allow in at cold cranking and during the warm up phase are both critical elements to a successful cold start.
Unfortunately with your stepper motor disconnected you have no real control over the air.
All you really have to work with is the amount of priming pulse fuel, temp corrected cranking fuel & warm up phase fuel you are throwing in.
You say when the engine is cranked with no throttle it fires but wont run.
This sounds like there is enough cranking fuel & no more air is needed, this is also supported by the fact when cranked with throttle it wont fire (too much air).
So just leave the cranking settings as they are, all you need the cranking settings to achieve is for it to fire.
Cranking & running are two very different conditions, which is why the system allows you to configure them separately.
As soon as the engine fires it moves to the temperature corrected running settings (warm up phase), if there is too much or too little fuel/air it will instantly die.
So with the cold cranking working as it should focus your attention on the temperature corrected running settings.
If I had your particular issue, on my Canems system I would be looking to add or remove some air supplied by the Bosch idle valve.
But with your stepper motor disconnected you are making your life much much harder to effect good temperature corrected running settings.
Unless you can reconnect the stepper & get the MS to drive it, you really only have two options, throw more fuel in or take some out on the temperature corrected running settings (warm up phase).
If stabbing the throttle can coax it into life I would look at adding more fuel first and see how you go.
From my limited experience playing with the cold start on my Canems it seems our cars need a lot of fuel to run for the first 20 - 30 seconds of warm up.
Hope some of this helps?
Cheers bloke, this is what I'm after, any more? Thing is the stepper was fine before conversion, then after had a mind of its own moving around at will during mapping. 
At the time it seemed the only way to map it was to disconnect the stepper otherwise I'd still be there and many [more] £££'s lighter.
At the time it seemed the only way to map it was to disconnect the stepper otherwise I'd still be there and many [more] £££'s lighter. macdeb said:
Cheers bloke, this is what I'm after, any more? Thing is the stepper was fine before conversion, then after had a mind of its own moving around at will during mapping. At the time it seemed the only way to map it was to disconnect the stepper otherwise I'd still be there and many [more] £££'s lighter.
As I'm not using ms I can only give my experience using DTA, First thing I did was set the throttle butterfly at the recommended opening ( bearing in mind i have a 71mm buterfly) and adjust the air bypass screw till it would just about tick over , on the dta there is a start fuelling map which is temperature v engine rotations the figures are arbitrary but playing around with the %s I got it to fire up instantly with almost no cranking but it was very rich,you then have another map which is water temp compensation which again is in %. Using a laser thermometer and reading the real time temps from the ecu I added or subtracted the amounts till it ran. At the time it seemed the only way to map it was to disconnect the stepper otherwise I'd still be there and many [more] £££'s lighter. Remember to do it at all temperatures reducing as you go so it runs cleanly untill full temp is reached
Mine is still not perfect but I'm using 650cc injectors just to add to the challenge
Forgot to say its worth checking what fuel your throwing in at tickover you may need to adjust this too
How bad is your cold start ? mine takes three goes
First time revs up then dies
Second time revs up holds for a few seconds then dies
Third starts up struggles for a short time then it settles.
sometimes it starts up running all over the place ,the afr is showing 18afr so i have to try again.
The first one done by the engine tuner took 5 minutes to go from 1800 rpm down to idle in very small steps . ...ridiculous!
First time revs up then dies
Second time revs up holds for a few seconds then dies
Third starts up struggles for a short time then it settles.
sometimes it starts up running all over the place ,the afr is showing 18afr so i have to try again.
The first one done by the engine tuner took 5 minutes to go from 1800 rpm down to idle in very small steps . ...ridiculous!
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