RX7 FD3S Cold start tuning

[Copyninja]

Good Afternoon,

I have noticed swapping to the link g4+ from the apexi pfc, my cold start and idle is quite poor. For e.g on the pfc the car would start up instantly and really quick and hold idle at 12-1300rpm. Newly rebuilt motor and compression is not an issue. 

On the Link ecu however, It cranks for what feels like an eternity (5s) before actually starting up and than idle quality does not match my idle target table of 1300rpm. On hot starts no issues whatsoever start up within 1s on half a turn of the ign key.

Please can someone help point me in the right direction.

1. Getting the engine to cold start asap; Not certain why it wont on the link ecu.

2. Why it wont respond to my idle target rpm of 1300rpm? 

I have done a quick log and can see its cranking at 147rpm for 5s and than gets to 250rpm and higher and than starts up. So I suspect if i can get it to crank at 250rpm from the start....it will start up immediately on a full cold start up....but not sure how to do this in the software?

Any help appreciated.

cold start.llg

[Adamw]

Your low cranking RPM is due to your low battery voltage.  I would generally consider anything less than 10.5V a problem, you only have 7.0v.

For the idle speed issue we will need a PC log with all parameters logged and a copy of the tune.

[Pete_89t2]

Adam is spot on with the battery; I can also see in that log that your alternator isn't putting out enough juice to charge the battery (i.e., >13.5V) until your RPMs get above ~ 1500RPMs, so there may be an alternator issue as well to deal with. Recommend putting in a new battery, and then test your charging voltage at idle.