Originally Posted by 16g-95gsx

The issue is related to the trigger disks as others have mentioned. In an ideal world AEM wants a 12 tooth crank trigger wheel, and a 1 tooth cam trigger wheel. Therefore 24 teeth of the crank represents 1 engine cycle. The cam tooth would be considered a reference, so AEM would know to expect 24 crank teeth between each cam pulse, and therefore any more or less crank teeth would be considered an error. It then will define engine position, or timing, based on where it is in the tooth count with each new tooth counting as 30* crank degrees of additional rotation. The system calculates RPM based on the time or period between each new crank tooth, and you can log this value as "crank period". It then will infer timing degrees based on this value. The more teeth you have on your trigger wheel, the better the tendency for higher timing resolution in AEM, with AEM accepting a maximum of 24 total teeth per engine cycle (12 tooth trigger wheel).

Now, here's where your starting problem happens. Everytime you shut your engine down, the crank and cam will be at a different position, and the ECU must "Sync" itself with what is actually happening mechanically. For the factory ECU that is no problem as it only needs to recognize one type of trigger configuration and you'll likely notice that the factory trigger wheel is made in such a way that this can happen VERY quickly. However, AEM needs to be more universal, and therefore it needs to be able to recognize multiple types of user defined configurations. This is useful, but aso means that AEM must get a number of pulses and sometimes rotations before it an consider itself "sync'd". Hondas are great at firing up quickly because most of them come from the factory with a 12-1 tooth pattern already (and this is probably what AEM was catering to when they made 24 teeth the max allowable). Triggerdisk.com which is founded by a friend of mine, simply has replaced the factory trigger disks with that of the ideal AEM 12-1 pattern.

When you look at AEM, log "stat sync", and the moment that value goes to "ON" the car should fire up. If it doesn't, then you have a bit more to play with on your fuel and timing during startup. If it fires up immediately, then that is as good as you're going to get on your trigger wheel setup.

Hope that helps,