vt 3.8 to vx 5.7 convertion starting problem

[vt5.7wagon]

hi guys i have just done a engine swap to my vt all went in great but having problems starting it fires but stalls straight away i used the vx 5.7 ecu and gearbox computer but didnt replace the bcm its like the ecu finds somthing wrong and shuts down. it only cranks for 3 or 4 seconds and might fire up in that period but then stalls. it had a maffless tune allready done and i fitted a cam. its got fuel presour
even with the fuel pump realay out it only cranks for 3 or 4 secs
its like you have to be quik to turn the key and crank it or it dosnt even crank
i have tryed the spare key and replaced the key reader
thanks guys want to get this bad boy on the road

[acarmody]

You need to get a Tech-2 to pair the ECU with the BCM or else the security system kicks in and goes THIEF.

All Holden dealerships will have one, or some of the better Auto-Sparkies might have one.

[gunsmoke]

We had a simular problem when we put an R8 manual engine into a Merc 300c. We solved that by changing to the auto computer...but you said you have the auto computer from the box didnt you..so I guess Im no help sorry bout that.

[letthiswork1]

If you don't mind me asking.. How much did this conversion set you back...?