I know we have these threads all the time. We've checked, double checked, tripple checked the grounds. Done VATS relearn. I've even disabled the anti theft and still have no spark when cranking.

Getting a Crank Position Sensor code so we swapped it for the one that was in his 4.8. Cleared the code and it still came back.
Gonna check on getting a new one tomorrow if O'Reilly's is open but if that doesn't do it i'm stumped on what else to check.

 

24x or 58x crank?

 

did you try and crank it on the 4.8 tune? you shouldnt have had to change anything, just make some adjustments to the tune. this the same computer? or did you swap them out also

 

whatever is on an 04 lq4 should be the same as the 99 4.8

truck is a 99 and we used 02 injectors. I loaded an 02 6.0 LQ4 tune. I don't see how that would be any different than using an 02 4.8 tune and swapping displacement, ve and such.

I can switch to an 02 4.8 tune and make adjustments and try it again tomorrow. but I really don't see what the difference would be

 

[QUOTE=viciousknid;4647338]whatever is on an 04 lq4 should be the same as the 99 4.8



well you can tell by the color of the senor a 24x is black and the 58x is grey from what i remember.

 

both had black sensors.

 

Don't waste your money on a new crank position sensor Joshua, it's highly unlikely that the sensors from both engines went bad...I'd check all the wiring to the sensor and the terminals at the connector, as well as the wiring to the PCM. Any chance that the reluctor on the crank of the LQ4 got damaged?

 

i suppose it's possible but i never noticed any damage on it. Going to check the wiring tomorrow if I don't have to work.

 

Dis crank relearn and code went away but still no spark

Tried 02 6.0 tune and his stock 99 4.8 tune but still no spark.
Checked all fuses and grounds several times. Everything is connected

Not sure what else to do

 

Did you do a full write or just a calibration flash?