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Just posting in case it helps someone
Car has PFC and would start cold just fine but not warm/hot. Either just crank and not start, backfire or very long cranking before starting unless i did pedal to metal then it would start.
After reading all relevant threads here and chasing things on the engine without any success, I decide to plug in OEM ECU and car started fine cold or hot to my surprise.
So i finally found a PFC thread (thanks @arghx) that talked about Cranking Inj Time.
I was shocked to find this in settings:
Anyone see the problem?
Changed the top 2 to 12/17 and car starts like a clockwork.
I know for a fact this car was tuned about 10yrs ago with ~300whp on dyno but seeing this i'm wondering how good the tuner was... or someone messed with pfc?...
thanks for sharing as you are probably not the only one to have such a problem. in lieu of the choke (you do remember "chokes") ECUs have a prime function. on many of the newer units you can select prime before you crank after turning the key to "on", or while the motor is cranking (like your Power FC) or... Off. in warm weather it is easy to flood the motor with too much injector on-time on crank. someone apparently entered some big numbers.
glad you solved the problem.. glad you shared it..
too much (38 ms) prime given his warm engine. of course this may be an issue for his motor (perhaps lower compression or fuel pressure or...) i don't use any prime.
which references this page from the Power FC manual:
where you can see the default cranking fuel map. I suspect whoever tuned the car was getting slow start times for whatever reason during the tuning process and was trying to throw more fuel at it. That could be compensating for having the wrong injector settings, or spark timing, or some other issue.
as you probably know there are a lot of factors that influence cold start settings so what works for one setup may not work for another. i now live at 2200 ft in NE Ga and mornings can easily be in the high 30s for parts of the year. i find my car starts cleanly with no pre-crank or crank prime. after the first 3 seconds of running my fuel enrichment kicks in and tapers off as the coolant temp rises. so i do have enrichment, just not on initial crank. what works for me may not work for others.
last week i loaded a new map and after a bit of driving on restart the motor flooded. for some reason the new map had pre crank (3 ms) enabled and flooded the motor. i run 1365 injectors in the primary so of course that was a factor. ambiant was around 80. coolant temps just driving around are normally 67C/150F.
as you probably know there are a lot of factors that influence cold start settings so what works for one setup may not work for another. i now live at 2200 ft in NE Ga and mornings can easily be in the high 30s for parts of the year. i find my car starts cleanly with no pre-crank or crank prime. after the first 3 seconds of running my fuel enrichment kicks in and tapers off as the coolant temp rises. so i do have enrichment, just not on initial crank. what works for me may not work for others.
last week i loaded a new map and after a bit of driving on restart the motor flooded. for some reason the new map had pre crank (3 ms) enabled and flooded the motor. i run 1365 injectors in the primary so of course that was a factor. ambiant was around 80. coolant temps just driving around are normally 67C/150F.
OP, what is the size of your primary injectors?
As far as i know, everything engine related is stock, except 3mm apex seals, coolant radiator and PFC.
I started lowering -80C value down and found car started somewhat ok at 15ms.
Then somewhere on this forum i found default pfc timings: 12, 17, 32, 59, 87, 104.
Only first 4 were bumped up on my engine. Cold temp values weren't far off so it didn't matter.
