Jay Purcival
New Member
Hi all, I recently bought a non running ucf20 LS400 1996 hoping to get it going easily. I later discovered the previous owner had replaced the ecu and had no luck starting it since and the old ecu is gone. I have tested cam and crank sensors, spark is good, compression is good and it will fire with starter fluid but will not keep itself alive. I have discovered while cranking the earth side of the injectors will not actuate so I am not getting any injection pulse or command. The other thing that makes this suspicious to me is the absence of a security light. LED works when powered externally but no security light activity when you put the key in the ignition or lock the vehicle. I have 2 keys and a wireless fob, 1 genuine black key, 1 aftermarket key with separate wireless fob. Have attempted virginising immo ecu and leaving key in ignition. nothing changed. tried retrieving mil codes however mil stays on solid with ign. on. any help would be greatly appreciated and a direction to go in would be super helpful. immo delete would be a phenomenal solution for me but properly fixing helps too, I have an XGecu EEPROM reader/writer. ECU part number: 89661-50390 Immo ecm p.n. : 89780-50010. Non vvti engine vin starting with JT753UF
