LS2 will crank but not start
03-07-2008, 01:09 PM
#1
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LS2 will crank but not start Hey guys
I swapped a LS2 from a 05 GTO in my RX7 and have now completed the work. The problem is the engine just wont fire up. It will crank happily but I get no fuel and no spark. My wiring is done right I checked it many times and I get the switched constant 12V to the coils and the injectors its the pulsed signal that is totally lacking. I have Aeroforcetech OBD2 gauges hooked up to the OBD2 port and they show my all the engine stats. I get an RPM signal on cranking and it does some stuff with the fuel tables as I see it. The gauges also have a option to show DTCs but no faults show up.
Fuel Pump gets turned on an primered by the ECU and the fuel pressure is right at 58PSI.
Does anybody have an idea what it could be? I double checked on everything. Engine and is PCM are perfectly grounded. The switched and constant 12V sources are clean and all fused.
I swapped a LS2 from a 05 GTO in my RX7 and have now completed the work. The problem is the engine just wont fire up. It will crank happily but I get no fuel and no spark. My wiring is done right I checked it many times and I get the switched constant 12V to the coils and the injectors its the pulsed signal that is totally lacking. I have Aeroforcetech OBD2 gauges hooked up to the OBD2 port and they show my all the engine stats. I get an RPM signal on cranking and it does some stuff with the fuel tables as I see it. The gauges also have a option to show DTCs but no faults show up.
Fuel Pump gets turned on an primered by the ECU and the fuel pressure is right at 58PSI.
Does anybody have an idea what it could be? I double checked on everything. Engine and is PCM are perfectly grounded. The switched and constant 12V sources are clean and all fused.
03-07-2008, 06:14 PM
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Both crank and cam sensor are securely fitted in the plug and plugged in. I meassured through from sensor harness to the PCM and both paths are free of problems. Dont have an oszi so cant check the sensors.
03-07-2008, 10:31 PM
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Sounds like you might not be getting a cam signal. Wonder if they re-pin to clean up the harness and the cam wires got switched. There different from a LS1 to a LS2.
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03-24-2008, 06:08 PM
#9
make sure the reluctor wheel and the crank sensor have the correct distance between the two. on my engine build somehow one of those fins got bent just the tiniest bit and the crank sensor wouldn't pick up the signal. bent it back put a file to it and it fired right up. pissed me off though...also check the wires on the crank sensor they can look like they are in threw the back, but give them each a little tug to make sure.
03-25-2008, 05:26 AM
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Did you run the starter (crank signal) wire FROM YOUR CAR directly to the LS2 starter or to the crank request pin on the ECM. Sounds like a VATS problem. Also you need power while cranking to the neutral safety pin of the ECM and clutch switch signal.
