XFI 2.05 very long initial crank , any ideas ?

gczarny

fast is cool !
Joined
Nov 13, 2005
I am heaving really long initial cranking problem 10-15 seconds before it fires up most of the time ,at times it will fire up right away but most of the time it takes that long to get it started ,after that will start right up till it sits for a while and then same long crank problem . My starter cranks fast enough ,new Optimo battery under the hood , cam/crank lights on XFI and XIM blinking but no go for 10 plus seconds .Volts shown by XFI about 0.2V less then what voltmeter reads at the batery ,fuel pressure 45 key on while cranking 50 psi ,battery 10.5 volts or more while cranking , I tried adjusting injector offset - batt volts , crank fuel , timing from 20 to 35 deg , seams no different . Ran out of ideas , anybody have this problem ? I will be happy to post tune and log files in anybody willing to look at them .
Thanks
 
Sounds like it needs more cold cranking fuel

Sent from my SM-G935T using Tapatalk
 
Sounds like it needs more cold cranking fuel

Sent from my SM-G935T using Tapatalk
I did test when I turn key on ,wait 1 min for wide band to heat up and read properly and then crank and watch cranking AFR , tried from 7 to 12 by adjusting cranking fuel ,same thing and it does not matter if this is cold start or engine is at 170 F ,if it sits for 5 minutes it will have long crank first time and will start right up after that , anybody can post their cranking AFR with easy starting engine ?
Greg
 
Did you verify toming with a light?
yes , dead on
Did you verify toming with a light?
Yes , dead on . Talked to Cal the other day ,he made a point that if the engine stops in "bad spot " it make take a while for XFI to resynch cam/ crank pulses if batt volts are low /crank slow , that's not it ,it cranks fast enough to resynch it in less then 10 seconds , not to mention if it starts I can kill it righht away and after XFI resets it will fire right up every time , the problem started shortly after update to 2.05 from 1.34 but not right away so can not blame it on the upgrade yet .I am out of ideas on this one but I am NOT going to call it NORMAL .
Greg
 
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I know I have to wait 5 sec or so after I turn the key on to start the car. If I don't wait and hit the key to start it won't start just turns over. Wait a few seconds and it fires right up.
 
I know I have to wait 5 sec or so after I turn the key on to start the car. If I don't wait and hit the key to start it won't start just turns over. Wait a few seconds and it fires right up.
That's how I start mine too, fuel prime is set tp 5 sec so I wait till FP shuts off then crank , I will be trying few things over the weekend ,I also smell some gas while driving and I can NOT figure out where it is comming from under the hood , one time I was seeing wet around FP regulator where two halfs are bolted together it was fixed and fine for a while now I smell it again but can not see anything wet ? more then one gremlin here ? or just one ?
 
While cranking, the stock C3I ignition is in bypass mode and ECU is not controlling spark. The timing will be 10 degrees and trigger directly from crank sensor. There can be a delay as the C3I module will wait for a cam pulse to synchronize and it can take as long as two engine revolutions for the cam pulse to occur. Long cranking is most likely caused by improper fueling or air bypass. Also, if the fuel system does not hold pressure when off, it can take a bit to pressurize. Latest XFI has ability to "pump" extra fuel by pumping throttle before or while cranking (while fuel pump on). If you find a couple of light pumps on throttle before cranking helps, increase cranking fuel. If cracking and holding the throttle open a tad helps start faster, you may need more air bypass (starting IAC pos. vs. coolant temp.) during cranking.
 
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While cranking, the ignition is in bypass mode and ECU is not controlling spark. The timing will be 10 degrees and trigger directly from crank sensor. .
That's only true for stock ignition module ,with XIM you have full control of start up timing , I tried IAC start position from 255 to 125 ,made no diference , I have my second FP set up to come on by TPS at 60% ,I tried to pressurise system with second fuel pump few times and this also made no diference , today I pluged in brand new 3bar MAP sensor( car set overnight ) she fired up on first turn ,tried 3 more times waiting each time 20 minutes or so and she fired right up ,thought I had it ........NOT SO FAST , fourth 20 or so minutes wait and back to 15 seconds of cranking .
 
That's only true for stock ignition module ,with XIM you have full control of start up timing
Yes.. Sorry, didn't see the XIM reference. Are you seeing the cam LED on the XFI and on the XIM right away during cranking? The same applies to XIM; It has to wait for cam pulse to synchronize before sorting spark.
 
Yes.. Sorry, didn't see the XIM reference. Are you seeing the cam LED on the XFI and on the XIM right away during cranking? The same applies to XIM; It has to wait for cam pulse to synchronize before sorting spark.
yes ,both XFI and XIM crank and cam led are blinking right away but no go for 10 sec .I had spark tester on ign wire and it had spark ,just do not know if in synch .
Greg
 
yes ,both XFI and XIM crank and cam led are blinking right away but no go for 10 sec .I had spark tester on ign wire and it had spark ,just do not know if in synch .
Greg
I just wanted to let everybody know that my long cranking problem is fixed for sure , what it turned out to be was wiring/connection problem somewhere , I decided to go through all grounds and connectors I could think of ,unplug - spray contact cleaner - plug back in couple of times -you know the drill , for last 3 days car starts perfect , better then stock car :whistle: ,thanks everybody for input /help with this problem .
Greg
 
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