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DSMRossi
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Joined: 03/28/2020 - 14:17
Cold start - falls on face

Hey guys, new user here. This is my first EMS, but so far I love how user-friendly it is.

 

Anyhow - when my car is cold, I can't start it without holding the throttle down. If I try to start the car without holding the throttle in, it catches like it wants to start, then immediatly shuts down. It will do this over and over until I finally push the throttle in 50% or more, in which case it will fire right up and then go through the normal warm-up RPM sequence. Nothing I do to the initial crank pulse or the crank injector time seems to change anything.

 

Crank advance is at 5.1

Crank min rpm 50

Crank max rpm is 350

My idle FB above RPM 300 - is this too low?

DSMRossi
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Last seen: 2 months 2 days ago
Joined: 03/28/2020 - 14:17
Played with it more this

Played with it more this-morning. Seems as soon as it changes to stat-running, it pops over once and then dies out. Again, if I throttle it, it will fire up and run.

DSMRossi
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Last seen: 2 months 2 days ago
Joined: 03/28/2020 - 14:17
Another update. After more

Another update. After more logging it seems that on cold starts ONLY, the idle position drops to 0, thus closing the IAC?  

Once it's run a few minutes, the car can be shut completely down and turned back on and that value stays active.

 

 

 

AEM_NS
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Last seen: 1 day 20 hours ago
Joined: 06/06/2014 - 09:31
If it does out after cranking

If it does out after cranking and attempting to start, that's a sign that you don't have enough warm up enrichment fuel.  As soon as engine speed gets above Crank Max RPM, the fuel transitions from cranking fuel to main fuel which is controlled by the main fuel map and Warm Up Enrichment trim table (as well as the Start Extra vs Temp and Decay tables).  It sounds like you simply don't have enough injector pulse immediately after cranking to keep the engine running.  Sometimes what I'll do is actually turn the Crank Max RPM way up and "lock" the engine into cranking mode and then I can use the Crank Injector Time table to figure out what injector pulse the engine wants in order to cold idle.  Then once I figure that out, I adjust the appropriate trim tables to get the same amount of fuel and set Crank Max RPM back to its normal value. 

Also, you can't really dial in cold start, cold idle and warm up enrichment until your hot idle and hot start fueling is really spot on.  Have you already covered that?